A scientific look at reps and sets

Mr. Shoulders · #1 (**permalink**) 01-15-2010

…When planning a workout you should first determine the desired training effect and select a repetition bracket to suit that goal. The following illustrates the typical training effect of various rep ranges...

1-5 Reps = Maximal strength increases through enhanced neural drive
6–8 Reps = Optimal compromise of maximal strength and hypertrophy gains
9-12 Reps = Maximal hypertrophy gains leading to increased maximal strength
13-20 Reps = Strength-endurance gains and lower hypertrophy gains.

Using this table we can see that the best gains in strength are made using very low reps (1 to 5) whilst the best gains in muscle size (hypertrophy) are made using medium to high reps (6 to 12). The weight you lift will be dictated by the rep range you choose. If you are looking to gain muscle size you would select a weight that allowed you to perform between 6 and 12 reps. If you can only complete 3 reps the weight is too heavy. If you can do more than the chosen number of reps, the weight is too light. In addition to the above it should be noted that the fibers in your muscles are "typed" according to their oxidative capacities and how fast they fatigue. In simplistic terms you have slow twitch fibers (type-I) and fast twitch fibers (type-II). Fast twitch fibers respond best to low-rep training whilst slow twitch fibers respond better to high-rep training. Therefore, you should periodically juggle low-rep training, intermediate-rep training, and high-rep training to make the best progress.

A Scientific Look at Sets...

A set is a group of consecutive reps. There are a number of factors to consider in determining how many sets to include in a workout; assuming that nutrition and rest are in check the most important factors are as follows.

1. Number of Reps Selected It is generally accepted that there is minimum amount of time a muscle must be stimulated for maximum size and strength gains. Conversely there is a maximum amount of time a muscle can be stimulated before overtraining sets in. Basically the more reps per set you perform the lower the number of work sets you should perform and vice versa.

2. Number of Exercises Per Training Session The more exercises you perform per muscle part, the fewer sets you need to achieve an optimal training effect for each exercise.

3. Muscle Size The number of sets performed should be proportionate to the size of the muscle mass trained. You would therefore expect to use more sets when training larger muscle groups than you would with smaller muscle groups. In direct conflict with this is the fact that smaller muscle groups recover more quickly than larger groups; it should be remembered that many smaller muscle groups are worked when training larger muscle groups e.g. biceps when training back.

4. Training Level One or two sets per exercise are usually enough for beginners whilst experienced trainees will often require increased volume.

5. Muscle Composition Muscles that are inherently fast-twitch respond best to more sets. Muscles that are inherently slow-twitch respond best to fewer sets.