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.
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.
- 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.
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.