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Showing posts with label strength training. Show all posts
Showing posts with label strength training. Show all posts

Wednesday, September 21, 2011

Tips On Improving Your Cholesterol Profile

The beneficial effects on the heart and circulatory system of a having a low blood level (below 130) of LDL cholesterol and a high blood level (above 55) of HDL cholesterol are well established. It is also good to have a ratio of total cholesterol to HDL cholesterol of no more than 4.0. If your levels don’t meet these criteria, you might benefit from the recommendations listed in an online Men’s Health Magazine article by Bill Phillips dated September 13, 2011. It presents the following ways, purportedly based on scientific studies, of improving your cholesterol profile without drugs:

Raise Your HDL Level


  • Eat at least 2 oz (57 gm) of nuts per day.
  • Do endurance exercise at least 20 min/day
  • Do 3 sets of 6-8 reps of the half squat, leg extension, and leg press, with 2 min max rest between sets, 2x/wk
  • Take a 1000 mg calcium supplement daily with 400 IU of Vitamin D-3
  • Eat fresh, not processed, white fish (e.g. cod, sole, flounder)
  • Take a daily 10-20 mg polycosanol supplement
  • Drink cranberry juice
  • Eat 2.5 oz of dark chocolate daily
Lower Your LDL Level
  • Eat a grapefruit daily
  • Eat several small meals a day
  • Eat food fortified with oat bran
  • Switch from a margarine containing trans fats to a spread that doesn’t
  • Drink Concord grape juice
  • Take phytosterol or phytostanol supplements in pills or margarine form
  • Add whole grains, nuts, and beans to your diet
Bottom Line

These seem like good recommendations. Just observe the following precautions:
  • Don’t overdo the calories by adding these items to your diet. Remove other items when you add these.
  • Endurance exercise is important for everyone. Weight training alone is not optimal for health.
  • Do not exceed 1000 mg of calcium/day from all sources (1200 mg/day if you're over 70) because of a possible increased risk of prostate cancer.
  • Don’t eat only white fish, because darker, fattier fish like salmon and mackerel are high in beneficial omega-3 fish oil.
  • Don’t overdo the juice because even natural juices contain a lot of sugar, especially fructose, which can increase fatty deposits in the liver and around the midsection.
  • Look for brands of dark chocolate without added milk fat.
  • Several small meals means SMALL.
  • The margarine brands that contain phytosterols and phytostanols contain some trans fats that are not listed because they're less than 0.5 mg per serving. So you may prefer getting these supplements in tablet form.

 

Monday, April 4, 2011

Effectiveness of Different Kinds of Strength Training Periodization

Periodization of strength training entails changing over time the weight handled in each exercise along with the number of repetitions per set. When the weight used is higher, the number of repetitions is lower and when the weight used is lower, the number of repetitions is higher. It is widely agreed among strength and conditioning professionals that periodized strength training is more effective than non-periodized training.

There are various versions of strength training periodization, including:
  • Traditional periodization - The trainee starts with relative light weights and high repetitions, and over a period of several weeks, increases the amount of weight lifted while decreasing the number of repetitions. For example, the trainee might begin by doing 10 repetitions per set with 60% of the maximum weight that can be lifted for a single repetition and progress to 4 repetitions with 80% of the max weight.
  • Daily Undulating Periodization - On different days, the trainee uses a different combination of weights and repetitions. A sample schedule might be medium weight and medium reps on Monday, light weight and high reps on Wednesday, and heavy weight and low reps on Friday.
  • Weekly Undulating Periodization - Weight and reps fluctuate from week to week. A sample schedule might be low weight and high reps on week 1, medium weight and medium reps on week 2, and high weight and low reps on week 3, with this 3-week pattern repeating several times.
A recent study by Apel, Lacey, and Kell in the Journal of Strength and Conditioning Research (vol. 25, no. 3, pp. 694-703, 2011) sought to determine the relative effectiveness of traditional vs. weekly undulating periodization.

Experimental Procedure
Forty-two young, physically active men were divided into three groups of 14 that trained for 12 weeks as follows:
  • Control group - Performed no strength training
  • Traditional periodization (TP) - Increased the resistance in a fairly linear manner from 57% of max the first week to 80% of max the final week.
  • Weekly Undulating Periodization (WUP) - Started at 57% of max, but increased resistance over 3 weeks before reducing weight close to where it started and increasing it back again over 3 weeks. This was done over 3 cycles in which both the starting and ending weight for each 3-week cycle became greater than for the previous 3-week cycle, ending at 78% of max.
There were 15 different exercises selected to work the entire body. The exercises used, rest time, total exercise volume and average percent of maximum weight used were the same in both groups. There were 3 training sessions per week for the first 2 weeks and 4 per week for the remaining weeks, in which half the exercises were performed 2 days per week (e.g. Mon. and Thu.) and the other half on 2 other days per week (e.g. Tue. and Fri).

Results
  • Both periodized training groups increased significantly in strength, while the control group did not.
  • Increases in back squat strength were significantly greater for the TP group (54%) than for the WUP group (34%).
  • Increases in bench press strength were significantly greater for the TP group (24%) than for the WUP group (19%).
  • Increases in pull-down strength were significantly greater for the TP group (29%) than for the WUP group (19%).
  • Increases in dumbbell shoulder press strength were significantly greater for the TP group (48%) than for the WUP group (36%).
  • Increases in leg extension strength were greater for the TP group (39%) than for the WUP group (27%), although the between-group difference did not reach statistical significance.
  • There was more muscle soreness and fatigue reported among the WUD group, which may have hindered training progress.
Bottom Line
For this group of recreationally active males, traditional periodization produced superior results to weekly undulating periodization. The between-group differences were great enough to be meaningful.

Thursday, March 31, 2011

Is Cycling Actually Detrimental to Bone Health?

An article by Nichols and Rauh in the Journal of Strength and Conditioning Research (vol. 25, no. 3, March, pp. 727-734, 2011) showed that hours of weekly bicycling exercise, in the absence of weight-resisted or impact exercise may actually be worse for bone density than no exercise at all. While such exercise seems fine for keeping the heart, lungs, and circulatory system healthy, and bodyweight under control, the evidence shows that it is a poor exercise for bone health.

Experimental Procedure
The study tracked, over a 7-year period, bone density in the lumbar spine, total hip, and femoral neck (segment of the thigh bone adjacent to the pelvis) as well as body fat and lean tissue measurements of 19 Master’s competitive cyclists and 18 non-athletes, who averaged 51 years of age at the start of the study.

Results
  • At both the initial and final testing, the cyclists had consistently lower bone mineral density at all sites measured than the non-athletes.
  • After statistical adjustment for changes in body mass index, lean mass, calcium intake and exercise habits, the cyclists lost more bone mineral density over the 7 years than the non-athletes.
  • The subjects who reported doing weight-bearing or impact exercise lost significantly less bone density in the spine and femoral neck than those who did not do such exercise.
  • At initial testing, 84% of the cyclists and 50% of the non-athletes met the criterion for osteopenia (subnormal bone density).
  • At the final testing, 90% of the cyclists and 61% of the non-athletes met the criterion for osteopenia.
  • Six of the cyclists but only one of the non-athletes had full-blown osteoporosis (critically low bone-density) by the end of the study.
  • Even when they were made aware of bone-density problems, very few of the subjects changed their diets to include more calcium.
Bottom Line
The evidence provides a strong indication that cycling is not beneficial to bone health. If done in the absence of weight-resisted exercise (e.g. squat, deadlift) or impact exercise (e.g. running, gymnastics, dance) bone loss is likely to result. One hypothesis is that the lack of impact or weight on the bone fails to stimulate mineralization, while calcium-containing sweat is lost during heavy cycling exercise. Another possibility is that endurance exercise tends to suppress testosterone, which helps maintain bone mass. Older competitive cyclists are at great risk for bone fracture because of their low bone density and high risk of bicycle crashes. Weight-resisted or impact exercise should be started when people are young because that is when bone is most readily mineralized.

Tuesday, March 29, 2011

Maintaining Strength and Muscle Mass As We Age

An article entitled, “Staying Strong: How exercise and diet can help preserve your muscles” appeared in the April 2011 issue of the Nutrition Action Health Letter, a publication of the Center for Science in the Public Interest. The article stated some interesting facts, including:
  • Starting in their late 30s and early 40s, most people lose a quarter pound of muscle per year.
  • Several studies have shown that resistance exercise can restore and preserve strength and power, even at an advanced age.
  • Resistance exercise also helps prevent loss in bone density and may even reverse age-related loss.
  • People with Type II diabetes can lower their blood sugar by doing resistance exercise.
  • After a large protein feeding (~ 30 grams, the quantity in 4 ounces of cooked meat) both younger and older people show equivalent protein synthesis (muscle-building) responses.
  • After a small protein feeding (~ 14 grams, the quantity in an egg plus a glass of  milk) younger people synthesize about half the protein they synthesized in the large feeding BUT PEOPLE OVER 60 SHOW ALMOST NO PROTEIN SYSTHESIS. In other words, the larger protein portions are necessary for the older people to synthesize any protein at all. However, anything above 30 grams of protein in a meal is either burned off as energy or stored as fat. So extremely large protein meals do not aid in muscle-building.
  • Of the 9 essential amino acids that our bodies can’t manufacture and must ingest, leucine is by far the most important for muscle development, especially for older individuals. Researchers recommend a minimum of 3 grams of leucine per meal, in addition to other amino acids. Animal products generally have relatively high percentages of leucine. Protein from whey (a byproduct of cheese-making) is relatively high in leucine and makes a good protein supplement.
  • Plant protein contains a smaller percentage of leucine, but soy is the best of the common plant proteins in regard to leucine content.
  • According to researchers, ingesting protein shortly after exercise provides the greatest boost for muscle building. Two hours is the longest one should wait before ingesting protein after resistance exercise.
  • While the U.S. Institute of Medicine set a Recommended Daily Allowance (RDA) of 0.36 grams of protein per pound bodyweight per day, researchers feel that about 0.50 grams of protein per pound bodyweight per day can best promote muscle building and minimize muscle loss as we age.
Bottom Line
Regular resistance exercise and adequate protein intake are essential for increasing and maintaining strength and muscle mass, especially as we age. A daily protein intake of half a gram per pound bodyweight is recommended (e.g. a 200 lb person should take in 100 grams of protein daily). The protein should not be concentrated in one meal but should be distributed over the day in meals containing about 30 grams of protein.

Friday, February 4, 2011

13 Iowa Football Players with Rhabdomyolysis: A Case of Coaching Incompetence

Thirteen University of Iowa football players were recently hospitalized for rhabdomyolysis caused by extreme physical exertion. Symptoms of the ailment include dark-colored urine, fatigue, muscle weakness, and muscle tenderness. Although the athletes have since been released from the hospital, information has not been released as to whether any permanent injury has resulted.

Rhabdomyolysis is a serious medical problem. It occurs when myoglobin leaks out of muscle cells due alcoholism, crush injuries, heatstroke, extreme physical exertion and other causes. Just as hemoglobin in red blood cells carries oxygen to the muscles and other body tissue to provide energy through oxidation of carbohydrates and fats, myoglobin carries oxygen within the muscle cells to the mitochondria, which are the oxidative energy-production units within the cells. Myoglobin is a large molecule and, when it leaks into the blood stream, it travels to the kidneys for removal. However, the myoglobin molecules are too large for the kidneys to readily clear, and can easily block the kidney’s filtration system. In addition, myoglobin breaks down into potentially harmful compounds. Permanent kidney damage or even kidney failure may result, which may require lifelong dialysis or a kidney transplant. See the National Institutes of Health for further information on rhabdomyolysis.

Extreme muscle soreness brings with it with a significant risk for rhabdomyolysis. Virtually all muscle soreness is attributable to the eccentric phase of exercise, which occurs when the muscle is lengthened while resisting. This occurs in the lowering phase of every weightlifting or calisthenic repetition, and also in the initial ground-contact phase of running, particularly downhill running. It also occurs during the deceleration phase of sports activities, as in braking for directional change and bringing a moving limb to a halt.

There is no excuse for any strength and conditioning coach to induce rhabdomyolysis. The press has reported that the workouts of the Iowa football players were extremely severe and may have been used as a punishment. One athlete said, “I had to squat 240 pounds 100 times and it was timed. I can’t walk and I fell down the stairs.” Another one said, “Hands Down the hardest workout I’ve ever had in my life!”. In addition, the severe workout occurred just after the athletes returned from winter break, during which most of them had not engaged in heavy resistance exercise. That made them particularly vulnerable to extreme muscle soreness and rhabdomyolysis.

Such an approach is totally unnecessary. Firstly, exercise should never be used as a punishment. Secondly, any knowledgeable and competent coach has to be aware that any exercise regimen that induces extreme muscle soreness presents a significant risk for rhabdomyolysis. Muscle soreness is not a prerequisite for muscle strengthening! The most effective way to increase strength is to start with light resistance and gradually increase the weight lifted over a period of time as the muscles strengthen. High repetitions are totally unnecessary for strength and power athletes like football players. Muscle fatigue following a workout is expected and desirable within limits, but muscle soreness is unnecessary and can actually slow down progress in strength development.

An extensive article and interview of coaches, doctors, and a parent of one of the players is available on the Internet.

Tuesday, January 4, 2011

Does Heavily Advertised Exercise Equipment Really Provide Advantages?

Advertisements on TV and elsewhere make it appear that, if you buy the latest innovative exercise device you will make faster and greater gains than you could using more conventional exercise equipment. Unfortunately, such claims, however seductive, do not usually stand up to scrutiny. The following articles in the December 2010 issue (vol. 24, no. 12) of the Journal of Strength and Conditioning Research highlight instances in which such equipment fails to provide any training advantage over standard exercises.

An article by Youdas et al. (pp. 3552-3562) compared the electrical activity of 4 chest, arm, and shoulder muscles of 20 subjects doing pushups using the Perfect-Pushup device and the same subjects doing standard pushups. The Perfect-Pushup device allows free horizontal rotation of the hands during the pushup movement while, during the standard pushup, the hands maintain their position throughout the movement. Pushups both with and without the device were done 3 different ways - using wide, shoulder-width, and narrow hand placements. While the results showed some small advantages of either the Perfect-Pushup or standard pushup as to the intensity of involvement of specific muscles when using particular hand positions, neither the Perfect-Pushup nor standard pushup showed any overall superiority to the other form of exercise. Hand position had a much more striking effect on muscle involvement, indicating that pushups should be done at various hand placements in order to stimulate a wide range of chest, shoulder, and arm musculature.

Another article by Youdas et al. (pp. 3404-3414) compared exercise using the Perfect-Pullup device to standard pull-ups (overhand grip) and chin-ups (underhand grip) using an overhead straight bar. The Perfect-Pullup device allows free horizontal rotation of the hands during the pull-up movement while, during the standard pull-up and chin-up, the hands maintain their position throughout the movement. Muscle electrical activity sensors were used to monitor the effort of 7 different muscle groups for 21 men and 4 women during the exercises. The results showed that, while there were some significant differences in muscle activation between the chin-up and pull-up, there were no significant differences between the Perfect-Pullup device and either the chin-up or pull-up. The authors concluded that the Perfect-Pullup device did not provide any advantage over standard pull-ups or chin-ups.

An article by Willardson et al. (pp. 3415-3421) compared the electrical activity of 3 abdominal muscles and 1 set of back muscles during 3 traditional trunk exercises and abdominal exercise using a device called the Ab Circle. Results showed no statistically significant differences in muscle activity between the Ab Circle and standard exercises. Yet the mean activity of the rectus abdominis muscles (6-pack) and lower abdominal stabilizer muscles was highest during the standard crunch, and the erector spinae (low back) muscles and external obliques (lateral waist) were most active during the side bridge. Thus the Ab Circle provided no advantage over standard calisthenic exercises for working the abdominal and low back musculature.

An article by Schoffstall, Titcomb, and Kilbourne (pp. 3422-3426) compared the electrical activity of 5 muscles involved in abdominal and hip flexion (upper rectus abdominis, lower rectus abdominis, internal obliques, external obliques, and rectus femoris) during the following isometric exercises:
- Crunch
- Supine V-up (while facing upward, back and legs rise off the ground to make a V-shape)
- Prone V-up (while facing down, butt rises up while hands and feet approach each other, making inverted V-shape) done as follows:
  • Feet on ground (no equipment)
  • Feet on FB large exercise ball
  • Feet on Power Slide
  • Feet supported by TRX suspension straps
  • Feet on Power Wheel
The results showed that:
  • All exercises stimulated the external obliques, upper rectus abdominis, and lower rectus abdominis similarly
  • The supine V-up without equipment showed greater internal oblique activity than the V-up done on the slide board.
  • The rectus femoris was less active during the crunch than during any of the other exercises. This is not surprising since the knees are specifically bent during a crunch to take the hip-flexors out of play and focus only on the abdominal muscles.
  • Overall, the prone and supine V-up exercises done without equipment provided as much training stimulus to the muscles tested as did the prone V-up using any of the commercial equipment.
Bottom Line
These studies indicate that much of the exercise equipment heavily marketed to the public provides no advantage in training stimulus over standard exercises. The only advantage of such equipment is that it provides variety, which may be important to maintain the motivation to exercise. Some exercise enthusiasts, even when informed that such equipment usually provides no shortcuts to the results they desire, may still wish to purchase them in order to keep their workout fresh, and that is fine. However, for those who would rather use their money for different purposes, there are other ways to add variety to a workout. Using standard gym equipment, a wide variety of exercises can be performed, especially using free-weight barbells and dumbbells and an overhead bar for hanging exercises.

Thursday, November 18, 2010

The Drawback of Exercising on Unstable Surfaces



Stability training, mainly in the form of lifting weights while standing on unstable surfaces, became somewhat popular with the advent of the Bosu Ball, which is a hemispheric ball about 2+ feet across mounted on a flat plastic base. The idea is that the instability of the surface brings muscles into play that are required for maintaining stability; muscles that would be minimally involved when exercising on a stable surface.

A study by Chulvi-Dedrano et al. in the Journal of Strength and Conditioning Research (vol. 24, no. 10, pp. 2723-2730, 2010) tested force production and muscle electrical activity during deadlifts on a stable surface and on two different unstable surfaces.

Method
31 young adult subjects did the following:
  1. Isometric deadlift in which the lifter pulled upward maximally for 5 seconds against an immovable bar
  2. Dynamic deadlift in which a barbell weighing 70% of the individual’s maximal isometric deadlift was lifted for 5 repetitions 
Lifting force was measured during the isometric efforts. Muscle electrical activity of the lower back muscles (paraspinals) was measured during both the isometric and dynamic lifts to indicate how hard the muscles were working. Both of the lifts were done on the following 3 surfaces:
  1. Stable floor
  2. Bosu Ball
  3. T-Bow (a curved board that can rock laterally as one stands on it)
Results
  • In the isometric deadlift, both the force produced and the muscle electrical activity were significantly higher on the stable surface than on either unstable surface.
  • In the dynamic deadlift, muscle electrical activity was significantly higher on the stable surface than on either unstable surface
Bottom Line
This study backs up other ones that have shown that exercising on unstable surfaces does not provide as much stimulus as stable-surface training to the main muscles (prime movers) used to effect the exercise movement. It has previously been shown that more weight can be handled when lifting on stable than unstable surfaces, providing greater stimulus to the muscles. In view of these factors, training on unstable surfaces is not best for increasing the size or strength of the major muscles. However, since such training does bring stability muscles into play, it can be effectively used as a supplement to training on stable surfaces, especially for athletes who engage in sports in which maintaining stability is of major importance (e.g. hockey, figure skating, snow-boarding, gymnastics). The major part of the resistance workout should still be on stable surfaces.

Tuesday, October 26, 2010

Plyometric Training for Improved Sports Performance

Plyometric training has been popular among strength and physical conditioning coaches for a number of years. Yet many people who exercise on their own are not familiar with this method. Simply put, plyometric exercise involved rapid stretch and shortening of a muscle. This occurs in such movements as hopping, jumping, and bouncing. For example, when you jump vertically, you naturally first do a countermovement in which you bend your knees quickly while stretching your quadriceps (front thigh) muscles, then rapidly contract those muscles to straighten the knees and propel the body upwards. Thus, repeated vertical jumps are one kind of plyometric exercise.

There are various gradations of plyometric exercise, and it is considered prudent to start with low-stress ones before progressing to more difficult ones. One of the most stressful plyometric exercises is depth-jumping, in which one jumps down from a box and, after contacting the ground, immediately jumps vertically. This is considered dangerous for anyone who does not already have a strong lower body and has not progressed from low-stress, through moderate-stress, to high-stress plyometric exercise. Various sources have recommended being able to squat with 1.5 times one’s bodyweight before taking on a serious plyometric exercise program. However, it is generally considered safe for people in good health without orthopedic problems to perform low-stress plyometric exercises like low bounces, hops, and jumps.

A recent study by Chelly et al. in the Journal of Strength and Conditioning Research (Vol 24, no. 10, pp. 2670-2676, 2010), showed how effective plyometric training can be.

Method
A group of experienced young male soccer players, average age 19 years, trained as follows:
  • August - preseason training consisting of light resistance exercise and calisthenics
  • September through March (the competitive season) - The players trained 5 days per week for 90 minutes by doing skill and tactical drills along with 30 minutes of continuous play. On one day per week they engaged in a competitive soccer game against another team.
The subjects were divided into 2 groups:

Group 1 only did the training program above.
Group 2 did the training program above plus from January-March they also did the following plyometric training twice per week:
  • Week 1: 5 sets of jumping over ten 40-cm (24“) hurdles spaced 1 meter (39.4”) apart
  • Week 2: 7 sets of jumping over ten 40-cm (24“) hurdles spaced 1 meter (39.4”) apart
  • Week 3: 10 sets of jumping over ten 40-cm (24“) hurdles spaced 1 meter (39.4”) apart
  • Week 4: 5 sets of jumping over ten 60-cm (36“) hurdles spaced 1 meter (39.4”) apart
  • Week 5: 4 sets of depth-jumps from a 40-cm (24“) box
  • Week 6: 4 sets of depth-jumps from a 40-cm (24“) box
  • Week 7: 4 sets of depth-jumps from a 40-cm (24“) box
  • Week 8: 4 sets of depth-jumps from a 40-cm (24“) box

Extensive testing on speed, power, and jump height was performed before and after the training.

Results

The group that did regular soccer training did not show significant improvement in any of the pre-post tests.

The group that did plyometric training in addition to their regular soccer training showed the following statistically significant improvements:
  • Thigh muscle volume: +2.5%
  • Cycle ergometer absolute power: +4.5%
  • Cycle ergometer power relative to body mass: +5.9%
  • Jump height without a countermovement: +8.3%
  • Jump height with a countermovement: +2.5%
  • 40-meter sprint first step velocity: +18.2%
  • 40-meter sprint velocity over first 5 meters: +10.0%
  • 40-meter sprint velocity between 35 and 40 meters: +9.8%

Bottom Line
Although not all studies of plyometric training have produced improvements of this magnitude, it appears that the evidence supports inclusion of plyometric exercise in physical training programs for sports involving sprinting and/or jumping.

NOTE: This description of experimental results is for informational purposes only and does not constitute a recommendation. Anyone engaging in an exercise program should obtain proper medical authorization before doing so.

Tuesday, July 27, 2010

Grouping Exercises Saves Times While Providing Equal Benefits

The benefits of the multiple mini-circuit method of performing resistance exercise have been described previously in this blog. It involves doing a set of each of 2-5 exercises in a grouping, then repeating the cycle 3 or more times before going on to the next exercise grouping. The advantages include:
  • A lot of exercise can be done in a given time period.
  • Each muscle group has adequate recovery time.
  • Heart rate remains high, affording some aerobic conditioning.
  • The body becomes accustomed to intermittent high-intensity exertions, relevant to many sports.
A recent article by Robbins at al. in the Journal of Strength and Conditioning Research (vol. 24, no. 7, pp. 1782-1789, 2010) provides research support for this exercise method.

Study Method
18 physically trained men performed the following two exercises:
  • Bench Pull - lie face down on a bench and perform a rowing movement to raise a barbell lying under the bench
  • Bench Throw - Perform an explosive bench press movement throwing the bar upwards, using a specially designed machine that catches the barbell so it does not fall back down on the lifter
On one day they first did 3 sets of bench pulls followed by 3 sets of bench throws for a total of about 20 minutes of exercise. On another day, they alternated sets of bench pull and bench press, accomplishing 3 sets of each, for a total of about 10 minutes of exercise.

Results
Even though the alternating sets took half as much time as performing 3 sets of one exercise followed by 3 sets of the other exercise, the subjects were able to handle as much weight for as many repetitions of each exercise in both types of routines. In addition, measures such as bench press throw height, peak power, peak velocity, and muscle electrical activity were the same for both routines.

Bottom Line
While saving a lot of time, performing exercises in groupings worked the muscles as well as doing all sets of each exercise before going on to the next exercise. Thus, the grouping method enables a full workout to be performed in much less time or allows more work to be done in a given amount of time.

NOTE: Our descriptions of exercise programs are for educational purposes and do not constitute recommendations. Anyone embarking on a physical exercise program must be in good enough health to safely do so. Fitness to exercise can best be determined by a physician's clearance.

Friday, July 2, 2010

Can Mental Imagery Improve Physical Strength?

Mental imagery involves envisioning oneself performing a physical activity without actually doing it. It is currently used by many high-level athletes to enhance their physical performance. While the method is well-accepted for maintaining focus and consistency of technique, its use has recently been examined for improving strength as well.

Study Method
In a study by Lebon, Collet and Guillot in the Journal of Strength and Conditioning Research (vol. 26, no. 6, pp. 1680-1687, 2010) male college athletes who had not been weight training were put on a program of bench-press and leg-press training 3 times per week for 4 weeks. The only difference between the training groups was that the imagery group visualized doing each exercise during the between-set rest periods while the control group performed another thought task.

Results
Both groups improved in strength and the number of repetitions they could perform with 80% of the maximal weight they could lift during pre-training tests. However, the imagery group improved 26% in leg press strength vs. 21% in the control group. Repetitions with 80% of pre-training max increased 92% in the imagery group vs. 79% in the control group. Both between-group differences were statistically significant. There were no differences between training groups as to changes in bench-press performance and neither group showed any significant increases in muscle-size.

Bottom Line
It is known that the strength gains resulting from the first few weeks of training are largely due to neuromuscular adaptations rather than muscle-size increases. Mental imagery may enhance the neuromuscular component of strength change and thus the most applicable to novice lifters. It is not clear why the method was effective for the leg press but not the bench press.

Tuesday, June 22, 2010

How to Avoid Weightlifting-Related Shoulder Injuries

Terms used in this article:
  • Rotator cuff: Muscles (supraspinatus, infraspinatus, teres minor, subscapularis) that stabilize the shoulder joint and rotate the arm at the shoulder
  • Internal shoulder rotation: Standing with your upper arm against your torso with your elbow at a right angle, rotate your upper arm inward until your hand touches your abdomen.
  • External shoulder rotation: From the position you just attained by internally rotating your shoulder, rotate your upper arm outward so that your hand moves away from your abdomen, as you would when throwing a Frisbee.
  • Trapezius muscle: Extends from the back of your head and neck down your central upper back and serves to raise the shoulders and draw them backwards.
  • Range of motion: The number of degrees through which a joint can be rotated.

A recent article by Kolber et al. in the Journal of Strength and Conditioning Research (Vol 24, no 6, pp. 1696-1704, 2010) reviewed existing scientific research articles on shoulder injuries brought on by weightlifting. It noted that 25-35% of people who engage in resistance training sustain an injury severe enough to require medical attention and that 36% of such injuries are to the shoulder. The vulnerability of the shoulder is related to the high number of exercises that involve the shoulder, the great stresses the exercises place on the shoulder, and the unfavorable positions in which some exercises place the shoulder. In addition, many lifters do not warm up properly, select a balanced set of exercises, use proper lifting technique, or modify/eliminate exercises that cause pain. Major muscles are frequently worked to the exclusion of minor ones, leading to muscle imbalances. Shoulder muscles commonly injured include the pectoralis major, biceps, deltoid and rotator cuff group.

The Most Common Signs of Shoulder-Dysfunction Among Weightlifters:
  • Reduced internal shoulder rotation range of motion
  • Excessive external shoulder rotation range of motion
  • Underdeveloped external rotation strength relative to internal rotation strength
  • Underdeveloped external rotation strength relative to arm abduction (raising) strength
  • Underdeveloped lower trapezius strength relative to upper trapezius strength
  • Instability of the anterior (front) shoulder
  • Tightness of the posterior (rear) shoulder
Common Pain-Producing Exercises
The following exercises in which the upper arm is raised to the side and parallel to the floor while the forearm is vertical put the shoulder in a fully externally rotated position and are considered hazardous:
  • Behind the neck pull-down
  • Behind the neck overhead press
  • Overhead stack machine press in which the hands move rearward as the weight is lifted
Other exercises, although generally safe, also associated with shoulder pain:
  • Bench press
  • Incline chest fly
  • Supine chest fly
  • Dip
  • Biceps curl
The following may help to prevent weightlifting-related shoulder injury:
  • Discontinue any exercise that causes pain.
  • If an exercise hurts, try variations that do not hurt (e.g. bench press with rolled up towel on chest to limit movement).
  • Balance every push exercise with a pull exercise in the opposite direction.
  • Balance exercises involving major body movements (e.g. bench press, pull-down) with those that stabilize and rotate the shoulder.
  • Exercises that strengthen external shoulder rotation are particularly important (e.g. do the external rotation movement described above, resisted by weight stack cable or elastic band).
  • Do strength exercises for the lower trapezius (e.g. rowing motions with elbows high and shoulders drawn fully back).
  • Do flexibility exercises to increase internal shoulder rotation.
  • Do flexibility exercises to stretch the rear shoulder (e.g. Stand with upper arm parallel to the ground. Grip elbow with other hand and pull arm horizontally across the chest).

Wednesday, June 2, 2010

Caffeine May Interfere With Muscle Building

An online article in the Journal of Sports Science and Medicine by Wu and Lin (vol 9, pp 262-269, 2010) indicates that going heavy on the caffeine before resistance training may be counterproductive.


Experimental method
Ten men performed a workout consisting of 3 sets of 8 exercises. Each set consisted of 10 repetitions of 75% of the weight that could be lifted only once. On one day, the workout was performed an hour after caffeine ingestion and on another day an hour after ingesting a non-caffeinated placebo. The amount of caffeine was 6 mg/kg or about 475 mg for a 175 lb man. That’s about the amount of caffeine in one-and-a-half 16 oz Starbucks Grande coffees or four-and-a-half 8 oz cups of home-brewed coffee. Blood was analyzed at various times for levels of insulin, testosterone, cortisol, growth hormone, glucose, free fatty acid and lactic acid.

Results
As has been observed in previous studies, blood levels of free fatty acids were higher in those who ingested caffeine than in those who did not. That is why caffeine is considered an ergogenic aid (performance enhancer) for endurance sports. Long distance runners often take in caffeine to promote the burning of fats in preference to carbohydrates, allowing the limited store of carbohydrates in the muscle and liver to last longer, sparing the athlete from “hitting the wall’ later in the race.

A result not noted in previous studies was that blood concentration of human growth hormone (HGH) was significantly lower when the subjects had previously ingested caffeine than when they hadn‘t. Since HGH is a muscle-building hormone, caffeine ingestion prior to resistance training can be considered counterproductive.

There were no significant differences in blood levels of insulin, testosterone and cortisol between caffeine and no-caffeine conditions.

Bottom Line
It appears prudent to avoid caffeine consumption for at least 3 hours prior to a resistance training session in order to maximize results. Since the time it take for the body to rid itself of half of ingested caffeine is approximately 5 hours in healthy adults, then excessive caffeine consumption is not recommended, even several hours before a workout.

Tuesday, May 25, 2010

Grouping Weightlifting Exercises for Time-Efficiency

The usual recommended rest period between sets of a weightlifting exercise is 1-5 minutes. Short rest periods are most often used by bodybuilders, while longer rest periods are often used by athletes looking to achieve maximum strength in specific lifts, such as those engaged in powerlifting or Olympic weightlifting competition. Most athletes and recreational lifters rest 2-3 minutes between sets.

Since the rest period between sets can account for the great majority of total workout time, some strength and conditioning coaches and athletes favor doing exercises in groups of 2-5, doing a set of each of the exercises in the group, then repeating the cycle 3 or more times before going on to the next group. The exercises within a given group involve different muscles. There is typically little time between sets but, because of the grouping system, more substantial time between sets of the same exercise. Such a routine has been called "multiple mini-circuits." The advantages of this type of program are that:
  • A lot of exercise can be done in a given time period
  • Each muscle group has adequate recovery time
  • Heart rate remains high, affording some aerobic conditioning
  • The body becomes accustomed to intermittent high-intensity exertions, relevant to many sports
The time-efficiency of such a workout is substantial. A typical weightlifting set takes about 30 seconds. If the trainee moves directly from one exercise to the next, there is generally only 30-40 seconds between the end of one set and the beginning of another. Thus, after becoming accustomed to this type of workout, a trainee can typically do 40-50 exercise sets in one hour, without sacrificing weight lifted or repetitions accomplished. In comparison, someone doing sets of the same exercise consecutively, with 2-3 minutes of rest in between, typically completes only 18-24 sets within an hour. Thus, performing exercise in groups allows one to either do twice as many exercises in a given amount of time or to take half the time to do the same number of exercises.

The exercises within a group use different movements and involve different muscle groups. A group might consist of:

  1. Push: bench press
  2. Pull: stack row
  3. Leg: squat
  4. Torso: leg raise
3-5 such groupings make for a comprehensive total-body workout. Done twice per week, this leaves time for a lot of other conditioning activities such as sport drills, plyometrics, distance running, speed work, and agility training.

The results of a research study by Robbins et al. (Journal of Strength and Conditioning Research, vol 24, no 5, pp 1237-1245, 2010) supports this type of training. In the study, following a warmup, 16 males performed 3 sets of bench press and 3 sets of bench pulls 2 different ways:
  1. 3 consecutive sets of bench pull beginning 4 minutes apart, followed by 3 consecutive sets of bench press beginning 4 minutes apart, for a total workout time of 20 minutes.
  2. 3 pairs of alternating sets of bench pull and bench press beginning 2 minutes apart for a total workout time of 10 minutes.
Note that both routines provided 4 minutes between sets of the same exercise. Analysis of the study results showed the two workouts similar in effect on the muscles. Both were similar in muscle electrical activity, the amount of weight lifted, and the number of repetitions performed in each set. The study also gave support for grouping more than 2 exercises together, as full recovery was not achieved with 4 minutes between sets of the same exercise.

Medical Disclaimer
This description of exercise practices and experimental results is for informational purposes only and does not constitute a recommendation. Anyone engaging in an exercise program should obtain proper medical authorization before doing so.

Monday, May 17, 2010

Making the Best Use Your Time in the Gym

I'm frequently amazed by how much time many people waste in the gym. This particularly applies weight lifters, because it is difficult to waste time when you’re on a cardio machine or in a group exercise class, both of which provide largely non-stop exercise. But lifting allows you to go at your own pace, so it is very easy to get lazy or distracted. You may have even been given the incorrect advice that a work-to-rest ratio of one to five is the right way to exercise.

I recently saw a gym patron talking on a cell phone most of the time and doing a minimum of lifting between conversations. I’ve seen many others standing around chatting for long periods. Then there are the people who do a set of exercise and sit on the bench or machine for 3-5 minutes before doing another set, oblivious to other people who are waiting to use the device. I even saw one gym patron reading magazine articles between sets. And personal trainers, who have great influence over their trainees, often chat extensively with their clients. That might be effective for promoting a client-trainer relationship, but it’s certainly not the best for physical conditioning.

Long rests between lifting sets is recommended for a very limited number of competitive strength athletes, such as Olympic weightlifters, who spend hours in the gym in their quest to maximize the weight they can lift and need long rest periods for full recovery and to focus on technique. However, such time-intensive programs are not effective for bodybuilders or athletes in most sports that require a good balance of strength, muscular endurance, and overall conditioning. It takes an inordinate amount of time to do a comprehensive workout when there is a lot of time between exercise sets. Most of us have lives outside of the gym and must work out efficiently to get the desired benefits within a limited amount of time. Even high-level athletes often must commit so much time to the practice of their sport that they do not have many hours in the week left to spend in the gym on training.

One way to do a comprehensive workout in a limited time is to work out in groups of 2-5 exercises. For example, you can first go through the following group 3 times: 1) an upper-body push exercise, 2) an upper-body pull exercise, 3) a lower-body push exercise, and 4) a torso exercise. After the first group is done, a second and then a third group of exercises are performed. While a beginner should rest as needed between sets, as one becomes conditioned , the only rest needed between sets is the time required to walk between stations and adjust the weight. Using this method, a well-conditioned lifter can accomplish more than 40 sets of exercise in one hour. Some advantages of this system are:
  • There is enough rest between sets of the same exercise to allow optimal recovery time for that muscle group.
  • Both strength and muscular endurance are developed
  • The heart rate stays up, providing some aerobic benefit
  • More calories are burned per hour.
  • The routine provides whole-body conditioning essential to most sports
  • The workout leaves more time to work on speed, power, agility, and endurance, as well as practice of one's sport.
Bottom Line
Time spent in the gym talking, sitting, standing around, or reading does not contribute to one’s physical development. A great majority of gym time should be spent exercising unless the gym is the center of one's social life. A routine based on cycling through groups of 2-5 exercises provides a lot of muscle work in a limited amount of time, and provides the added benefit of total body conditioning.

Thursday, April 29, 2010

Complex, Specific Training Improves Sports Performance

Introduction
It is much more difficult to improve the physical performance of highly trained athletes than of previously untrained subjects. Thus, it is noteworthy that the study described below by Alves et al. (Journal of Strength and Conditioning Research, vol 24, no 4, pages 936-941, 2010) produced significant performance improvement among elite young Portugese soccer players using brief exercise sessions once or twice per week.

Experimental Method
23 young elite soccer players underwent the following tests before and after an 8-week period:
  • vertical jump from a static, bent-knee position
  • vertical jump using a dynamic countermovement (natural quick knee bend)
  • 5 meter sprint
  • 15 meter sprint
  • soccer agility test
All subject initially did 2 weeks of general weight training before being divided into 3 experimental groups that did the following for 6 weeks in addition to their normal soccer training:

Group 1 - Once a week, before their regular soccer training session, they went through the following 3 exercise stations:
  1. 6 reps of squats with 85% of max weight, 5 meters of high-knee skipping, 5 meter sprint
  2. 6 reps of calf raises with 90% of max weight, 8 vertical jumps, 3 soccer-ball high-head hits
  3. 6 reps of knee extension with 80% of max weight, 6 jumps from seated position, 3 60-cm drop jumps
Group 2 - The same routine as Group 1, but done twice a week instead of once a week.

Group 3 - Control group - did no exercises supplementary to their regular soccer practice.

Results:
5-meter sprint time improved 9% for Group 1 and 6% for Group 2
15-meter sprint time improved 7% for Group 1 and 3% for Group 2
vertical jump from static bent-knee position improved 13% for Group 1 and 10% for Group 2
none of the groups improved significantly in the countermovement jumps or agility test
the control group did not improve in any of the tests

Conclusions
A relatively short exercise program of weight-lifting, jumping, and sport-specific movements performed once or twice per week can significantly improve the physical performance of elite athletes. Even though the results of the once per week and twice per week exercise groups did not differ significantly, it appears that the subjects responded better to doing the program once per week rather than twice per week when regular sport training was persued concurrently.

Thursday, April 8, 2010

Brock Lesnar's Workout - Perfect Example of Functional Training

See the video of one of Brock Lesnar's workouts. Lesnar is the current top heavyweight of the Ultimate Fighting Championship (UFC), the most popular mixed martial arts organization in the U.S. He won the NCAA heavyweight wrestling championship in 2000 and later became a professional (choreographed) wrestler. When he joined the UFC, he became a dominant force. Watch this highlight video to see his speed and power.

Lesnar's workout is a prime example of functional training. No doubt weight-lifting and running are essential for a base level of fitness. However, to really excel in a sport or other physically demanding activity, one has to train in ways that simulate the activity to be improved. Lesnar's routine is based on 5-minute rounds as are UFC fights. His exercises are mostly whole-body, multi-directional, asymmetrical, and highly taxing to the lactic-acid energy system. No doubt Lesnar does a lot of conventional weight-liting. However, his lesson to us is that, in order to excel in a sport or other physical activity, training must be supplemented by routines that simulate the target activity as to which muscles and energy systems are used and the way they are used.

Tuesday, April 6, 2010

Vibration Training Can Increase Jump Height

Introduction
Because of evidence supporting their effectiveness for improving strength, flexibility and power, whole body vibration platforms have become increasingly available in fitness centers and athletic training facilities. These platforms generally provide repeated vertical fluctuations at a user-selected rate and amplitude (distance). One study reported that frequencies of 20-30 Hz (cycles per second) produced the greatest gains in flexibility and strength. Amplitude adjustment generally ranges from 1-15 mm (0.04-0.60").

While it is easy to train previously untrained people to increase strength and power, it is more difficult to produce improvement in those already trained. Thus, the study described below provided a challenge to whole-body vibration training.

Experimental Method
In a study by Wyon, Guinan, and Hawkey published in the Journal of Strength and Conditioning Research (vol 24, no 3, pp. 866-870, 2010) 18 female undergraduate dance majors, who were currently engaged in 12-16 hours of dance training per week, were divided into the following two groups that were tested before and after a 6-week experimental period:

Experimental Group: In addition to their normal dance training, these subjects did whole-body vibration training two times a week separated by 2 rest days. The training consisted of twice holding each of the following positions for 30 sec while on a vibration platform set at a frequency of 35 Hz and amplitude of 4 mm (0.16").

     Half-squat with knees pointing outwards
     Right leg leading lunge
     Left leg leading lunge
     Maximal height calf raise
     Forward torso bend (at least 90 degrees) with knees straight

Control Group: In addition to their normal dance training, this group held each of the same positions as the experimental group, but on a stable floor rather than on a vibration platform.

Results
The experimental groups improved 2.3 cm (0.9" or 6%) in their maximal vertical jump, while the control group actually declined by 1.5 cm (0.6" or 4%). This difference was statistically significant.

Bottom Line
Whole-body vibration training appears to hold promise for training athletes and dancers. The experimental training required only 5 minutes twice a week. Because the physical demands on in-season dancers and athletes are great, strength and power training is usually limited to avoid overtraining. However, whole-body vibration training seems to be able to improve performance without excessively stressing the athlete. An added advantage is the previous evidence that such training can improve bone mineral density. Low bone density has been a problem with female dancers and athletes who maintain low bodyfat, such as gymnasts and distance runners.

Tuesday, March 16, 2010

Improving Performance in High-Level Athletes

Introduction
     It is not difficult to improve the physical performance of people who have had little or no intense training. Yet, it is much more challenging to improve the performance of high-level athletes who presumably have been training and competing at intense levels for considerable time. After all, their training and play have already stimulated their bodies to make major physiological changes, and many have likely reached a plateau by which they are no longer improving in their physical performance. However, a study by Wong et al. in the latest issue of the Journal of Strength and Conditioning Research (vol 24, no 3, 2010, pp. 653-660) shows that even the performance of professional athletes can be improved by a well-designed training program.

Experimental Methods
A group of Hong Kong professional soccer players were divided into 2 groups that trained for 8 weeks during the pre-season as follows:
  • Group 1: made up of 20 players who engaged in strength training and high-intensity interval training twice per week in addition to their regular soccer training. The strength training consisted of 4 sets of 6 repetitions of high pull, jump squat, bench press, back half squat, and chin-up. The high-intensity intervals consisted of sixteen 15-second sprints at 20% faster than maximal aerobic speed interspersed with 15-second rest periods. The method for determining maximal aerobic speed was not clearly described. However, it might be taken as the fastest pace at which one can run 3-5 miles (5-8 km).
  • Group 2: made up of 19 players engaged in only their regular soccer training.

Results
Only Group 1 improved significantly in the vertical jump (by 4%), 10-meter sprint time (by 6%), and 30-meter sprint time (by 3%).
Group 1 improved twice as much (20%) in a test of shuttle-running at progressively increasing speed as Group 2 (9%).

Bottom Line
Even high-level athletes can improve their physical performance by following a well-designed training program. Twice per week sessions of high-intensity interval training and weight training in addition to regular sport training appear effective for high-level athletes. It should be noted that this was pre-season training. Generally, during a competitive season, exercise other than regular sport-drills and competition is cut back considerably to avoid overtraining.

Medical Disclaimer
This description of experimental results is for informational purposes only and does not constitute a recommendation. Anyone engaging in an exercise program should obtain proper medical authorization before doing so.

Tuesday, March 9, 2010

Regular Stretching Can Increase Weight Training Gains

Introduction
The value of stretching has been somewhat controversial. While there is no doubt that stretching is necessary for athletes whose limbs go through extreme ranges of motion in their sports (e.g. hurdlers, gymnasts) there is little evidence that it benefits other athletes. Regular stretching has not been shown to reduce the incidence of injuries among runners, and static stretching done right before "explosive" activities like jumping and sprinting actually impairs performance (although not next-day performance). However, a recent study by Kokkonen et al. in  the Journal of Strength and Conditioning Research (vol 24, no 2, 2010, pages 502-506) indicates that regular static stretching can actually increase weight training gains, at least for the first several weeks of a training program.

Experimental Procedure
Group 1 - Performed 3 sets of 6 repetitions of knee extension, knee flexion, and
               leg press 3 days per week (Monday, Wednesday, Friday) for 8 weeks
Group 2 - Performed the same weight training routine as Group 1 but also did a stretching
               routine twice a week (Tuesday, Thursday) consisting of 15 stretches for the hamstrings,
               quadriceps, aductors, abductors, external and internal rotators, planter flexors, and dorsiflexors.
               Each stretch was done for 3 sets of 15-second holds with 15 seconds of rest in between sets.

Results
Group 1 improved in knee flexion, knee extension, and leg press max lifts by 12, 14, and 9% respectively, while Group 2 improved 16, 27, and 31% respectively. For the latter 2 lifts, improvement was significantly greater for group 2.

Bottom Line
A static stretching routine performed Tuesdays and Thursdays can increases strength gains obtained from weight training on Mondays, Wednesdays, and Fridays, at least during the first several weeks of a training program.

Wednesday, February 10, 2010

An Effective Method for Improving Sprint Speed

Introduction
Resisted sprinting has become a standard training method for sprinters and other athletes who rely on their sprint speed (e.g. football players). There are various way to provide resistance to sprinting, such as small parachutes pulled by sprinters, push and pull sleds and carts, and long elastic cords. Evidence for the effectiveness of resisted sprinting, especially in combination with strength training, was provided in a recent article by Ross et al. in the Journal of Strength and Conditioning Research (vol 23, no 2, 2009).

Experimental Method
25 college-age male athletes (American football, soccer, track and field), were divided among the following 3 training groups, all of which trained for 7 weeks:

  1. Resisted Sprint Training: Did 8-12 sets of 40-60-meter sprints on a treadmill with 2-3 minutes rest in between. A proprietary device pulled back on the sprinters with up to 25% of their bodyweight. 25-40% of the sprints in each training session were resisted and the rest were unresisted.
  2. Strength Training: Did a split routine of 10 weight-resisted exercises two days per week and 9 other exercises two days per week plus a core circuit each workout. Each exercise was done for 3-4 sets of 6-10 repetitions. There were 26-30 total sets per workout in addition to the core circuit.
  3. Combined-Training: Did both the Resisted Sprint Training and Strength Training programs described above, on different days.

Experimental Results
  • Only the Combined-Training group improved significantly in 30-meter sprint time.
  • The Resisted-Sprint Training group improved somewhat in 30-m sprint time, but the change did not quite reach statistical significance.
  • Only the Combined-Training group improved significantly in treadmill sprint peak power.
  • All 3 training groups significantly improved their maximum barbell squat (6.6-8.4 kg) without any statistically significant difference among the improvements of the groups.

Bottom Line:
Resisted Sprint Training, especially in combination with Strength Training, is effective in improving sprint time, even among athletes who are already practiced in their sports.