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.

　

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.

Minimalist or “Barefoot” Running Shoes

For decades, running shoes were rated by Runner’s World magazine and other organizations largely on their ability to absorb shock. As a result, manufactures made heels and soles increasingly thick to rank highly in the ratings. This led to shoes that were quite bulky and thickly padded. In a countermovement to this trend, and inspired by a track coach who included barefoot running is his training programs, Nike came out with the first of the modern minimalist shoes, the Free, in 2004. This lightly-padded shoe was only intended for occasional use, not full weekly mileage.

Proponents of minimalist running shoes say that, because of their light cushioning, people running in them alter their gait to lessen shock. Such changes include landing on the midfoot or forefoot rather than the heel, shortening the stride, increasing stride frequency, and lowering peak impact force. This is claimed to reduce this risk of tibial stress fracture, plantar fasciitis, and other overuse injuries, and to strengthen the feet. Biomechanical testing has verified that Africans who grow up running barefoot strike the ground with only a third of the impact experienced by U.S. runners in shoes. Lightweight shoes also lower the energy cost of running, so a runner can go at a faster pace at the same level of exertion, which translates into faster race times.  However, running experts have cautioned that any switch from heavily cushioned standard running shoes to minimalist shoes must be gradual in order to allow the muscles, bones, and tendons of the foot and leg to adapt.

The minimalist running shoe movement accelerated significantly with the publication of the 2009 book, “Born to Run,” which revealed that the Tarahumara Indians of northern Mexico get fewer injuries than U.S. runners even though they wear very thin rubber sandals and run extremely long distances. Manufacturers other than Nike came up with their own versions of minimalist shoes. Vibram, an Italian company, introduced its Five Fingers model, in which each toe is individually gloved. It weighs a scant 5.7 oz and has a heel thickness of only 7.2 mm (compared with up to 38 mm on heavily padded “cushion” or “motion control” shoes). This model is now the leader of the minimalist shoe market.

Other running shoe companies have jumped on the minimalist bandwagon. Saucony came out with its Kinvara model, which has somewhat more protection than the free and is intended for regular, rather than occasional, use. New Balance will debut its Minimus in February, which the company says will give a free-foot feel but still have cushioning in key spots. Merrel will put out its Barefoot Collection in February with a sole from Vibram and a very light upper. Also in February, Nike will supplement it Free line with its Lunar Eclipse lightweight stability trainer. Addidas will introduce a light, fast, everyday shoe in the Fall of 2011. Other companies that do not plan to introduce minimalist shoes have been making their existing models lighter and more flexible. Yet there is concern within some shoe companies that runners may switch to minimalist shoes too rapidly and subject themselves to injury.

An important factor in how long it takes to adapt to a minimalist shoe is the difference in thickness between the forefoot and heel padding. It can range from zero for a shoe with no difference between the thickness of heel and forefoot padding, to a 12 mm greater thickness of heel than forefoot padding. If one has been accustomed to running in a heavily padded shoe with a large difference between the padding thickness of heel and forefoot, the adaptation time to a minimalist shoe should be considerable.

As of now, there have been no published articles comparing the injury rate of runners wearing minimalist shoes vs. those training in standard shoes. However, many of the runners who have switched to minimalist shoes swear by them. Yet few market watchers expect such shoes to ever capture a major share of the running shoe market. Currently, no more than 10% of running shoes sold could be called minimalist.

Bottom Line
While few studies have been done on minimalist shoes, evidence suggests that such shoes do alter running gait so as to reduce the degree of foot-strike impact and also allow the foot to flex in a natural manner while in contact with the ground. However, since most Americans have grown up walking, running, and playing sports  in supportive shoes with heels more thickly padded than forefeet, the adaptation to relatively flat and lightly padded shoes can be difficult and potentially injurious. Additionally, such shoes offer little protection against foot injury that can occur when stepping on a rock, tack, or other object. Those who are willing to accept the risk of trying such shoes should do so with caution and increase the weekly mileage they run in them very gradually. It remains to be seen whether the benefits of minimalist shoes outweigh their risks.

Is Elliptical Training as Good as Running for Improving Fitness?

Elliptical trainers have become very popular in gyms as well as in the home. Their popularity is due to a lack of impact on the body while providing resistance to both the lower and upper body musculature. The movement pattern looks similar to running but does not involve pounding of the feet on the ground. An added advantage is the relative silence of an elliptical device compared to a treadmill, which produces considerable noise from foot strikes and its motor.

An important question is whether the elliptical trainer provides as good an aerobic workout as a treadmill or running outside. A study by Brown et al. in the Journal of Strength and Conditioning Research (volume 24, number 6, pp. 1643-1649, 2010) was designed to answer that question.

Experimental Procedure
9 male and 9 female college-aged subjects worked out for 15 minutes on different days on both a treadmill and an elliptical trainer at a difficulty level they self-selected as “somewhat hard.” The subjects were instrumented to collect information on their rate of oxygen utilization, pulse rate and other relevant variables.

Results
The only statistically significant differences between exercise on the elliptical machine and the treadmill were that the elliptical machine produced higher:

• heart rate
• percentage of maximal rate of oxygen utilization
• Ratio of carbon-dioxide produced to oxygen used

However, there were no significant differences in total energy expenditure or total oxygen consumption.

Bottom Line
The similarities between the responses to exercise on the elliptical trainer and treadmill were far more important than their differences. They both produced very similar aerobic stimulus to the body when the subjects worked out at a moderate level of difficulty, which is typical. Therefore, for general health, one can use an elliptical trainer with confidence. However, since running is a very basic human activity that is essential for sports and reacting to emergencies, run training is still generally more useful. Someone who trains exclusively on an elliptical machine and reaches a high level of fitness will not perform as well when faced with a running challenge, and muscle soreness will surely result. Yet, elliptical training is a good way to maintain cardio-respiratory function for injured athletes and others who cannot tolerate lower body impact. It can also provide variety in training for those who run regularly.

Should You Skip Breakfast to Burn More Fat During a Workout?

An Associated Press article suggesting that, because skipping breakfast before a workout burns more fat, such a practice may be effective for body fat loss. Yet, the study on which the article is based provides absolutely no evidence that such a practice would result in a stable loss of body fat. Sure, if your body is depleted of stored carbohydrates in the form of muscle and liver glycogen, you will burn more fat during exercise. However, a close look at the article reveals that the fat burned is in the muscle, and not around the waist or other parts of the body where people generally want to lose fat. Thus, exercising in a fasted state merely depletes intramuscular fat that is replenished upon eating. So there is no net body fat loss unless one consumes fewer calories than are used, which requires dietary control. So we can’t escape from the truism that the only way to lose weight is to burn more calories than you take in.

The following are additional reasons not to exercise in a fasted state:

• You will feel less energetic and more lethargic
• The quality of your workout will diminish
• Your motivation to exercise will be reduced
• You will cannibalize muscle to convert protein into needed carbohydrates

The only advantage to running in a fasted state might be for long-distance runners who wish to train their bodies to preferentially burn fat, thereby sparing muscle and liver glycogen to avoid “hitting the wall” late in a race. However, training with long-distance runs accomplish the same goal.

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.

The Magic of Interval Training

The evidence continues to mount that interval training is very effective in a number of ways. For those not familiar with interval training, it involves short bouts of intense exercise (usually running, cycling or rowing) interspersed with longer periods of light exercise. An example involving running would be to warm up thoroughly first, then run a quarter-mile (~400m) at 85-90% of max speed, then walk or jog an eighth-mile (~200 m), repeating the run/walk cycle for 8-10 repetitions followed by a warm-down. There are many variations of interval training, and some involve even shorter bursts of intense exercise (e.g. 200m runs).

A recent article in the Journal of Strength and Conditioning Research (Tanisho and Hirakawa, vol 23, no. 8, 2009, pages 2405-2410) reinforces the efficacy of interval training. The subjects were 18 Japanese male lacrosse players who trained 3 days/wk for 15 weeks on an exercise cycle. The continuous-training (CT) group pedaled continuously for 20-25 minutes, while the intermittent-training group (IT) alternated 10-second max-speed pedaling with 20-second easy pedaling, for a total of 10 intervals (total time = 5 minutes). There was also a control group that did no training. Interestingly, the IT group improved almost as much (10%) in the maximal oxygen uptake test (gold standard of aerobic fitness) as the CT group (12%). However, only the IT group improved in maximal power output. The IT group was also the only one to improve in fatigability, measured as the ability to maintain cycling power output over 10 intervals of 10-second max-speed pedaling interspersed with 40-second recovery periods.

One would have to conclude that the interval training produced amazing results. The 5-minute interval training sessions produced almost as much increase in aerobic capability as 20-25 minutes of endurance training. Yet the interval training also produced significant gains in maximum power and in resistance to fatigue from repeated intense exertions bouts. IT was a truly remarkable and time-efficient form of training.

This type of training is clearly advantageous for most team sports, which generally involve short bursts of intense activity interspersed with mild-to-moderate activity. The effectiveness of the interval training supports the concept of Specificity of Training, by which training is most effective when it reflects important aspects of the sport in which improvement is sought. Distance running is not effective for most team-sport athletes because it has been shown to actually reduce max power output, needed for jumping and sprinting. Thus long runs are only recommended for athletes in endurance sports.

A word of caution is in order. No-one should engage in an exercise program without first determining whether a doctor's clearance is needed first. See our Exercise Risk Questionnaire. Even if you are cleared for general exercise, you may not be ready yet for interval training, which should only be undertaken by people who are already well-conditioned. It is an intense form of exercise that puts considerable strain on the heart, lungs, muscles, and bones. Running intervals can easily cause muscle pulls or other musculoskeletal injuries, so very thorough pre-interval warmups are necessary. Cycling and rowing intervals involve less impact and peak force on the musculoskeletal system than running and are thus less likely to produce injury. However, any interval training must be approached with caution. The key points are to start with a well-conditioned individual, warm up very thoroughly, and start at a moderate level of difficulty, increasing the intensity of intervals over a period of several weeks.