Most bodybuilders train with sets of 6-8 reps using heavy weights, but some dissidents prefer to do sets of 10-14 reps using slightly lighter weights. One disadvantage of a training scheme with longer sets is that it contributes less to strength development, according to many handbooks. Not so, say sports scientists at Bergen University College in Norway.
The researchers got a group of about 30 students do weight training for 8 weeks. The students went twice a week to the gym and did sets of 6-8 reps. [6RM]
Another group of about the same number of students did the same but did sets of 10-14 reps. [12RM]
Before and after the training period the researchers measured the weight with which the students could just manage to squat for 1 rep [1RM Squat] on a Smith machine, and the weight with which they could just manage 1 rep bench press [1RM Bench press].
The figure below shows that both training methods had practically the same effect on the subjects’ maximal strength.
“Although the literature supports various resistance training protocols, complete consensus does not exist as to the most effective method to increase maximal strength”, the Norwegians write. “On the basis of the results from our study, we believe that the importance of high load in resistance training may have been exaggerated.”
“It is assumed that weight training with heavy weights represents a considerable risk of injury. Fitness enthusiasts, as well as patients with musculoskeletal dysfunction, should attempt to attain the benefits of resistance training by the use of the minimal external resistance needed to achieve the desired response.”
Sets of 6-8 reps build up just as much strength as sets of 10-14 reps
“The important factor is to design a programme for the individual to provide the proper stimuli to attain maximal benefit at the lowest risk. The results of our study support the notion that completing sets to exhaustion may be more important than a low number of repetition maximum within the span from 6 to 12 repetitions for healthy young adults.”
“Further investigations should be undertaken to examine if these findings may be generalized to patients with muscle weakness caused by musculoskeletal disorders.”
Comparison of two resistance training protocols, 6RM versus 12RM, to increase the 1RM in healthy young adults. A single-blind, randomized controlled trial.
The purpose of the study is to compare the effect in healthy young adults of two resistance training protocols, six-repetition maximum (RM) versus 12RM on maximum strength (1RM).
A single-blind, randomized controlled trial was used in the study. Sixty-two healthy physical therapy students, with age (mean [+standard deviation]) 23 (+2.6)? years, weight 67.4 (+11.7) ?kg and height 171.7 (+8.4) ?cm, of both genders who were recreationally active, but not training systematically, volunteered to participate in the study. They were randomized into two groups (group 1: 24 women and 8 men; group 2: 23 women and 7 men) by a block randomization procedure that ensured equal gender distribution. Sealed envelopes were used to conceal allocation to groups.
Group 1 did three sets of 6RM of each exercise, and group 2 did three sets of 12RM. Both groups performed the exercises twice per week for 8?weeks with 3?minutes rest between sets and exercises. Primary outcomes were maximum strength defined as one-repetition maximum squat (1RMSq) for lower-body strength and bench press (1RMBp) for upper-body strength. Secondary outcomes were body weight and Uro Kaleva Kekkonen (UKK) Fitness Index.
Both groups increased strength significantly (p?< ?0.001) in 1RMSq (6RM 13.6%, 12RM 13.5%) and 1RMBp (6RM 9.2%, 12RM 8.4%). There was no significant difference in the change between the two groups, no change in body weight and only a small increase in UKK Fitness Index.
Both 6RM and 12RM training protocols improve maximum strength in recreationally active healthy young adults, with no significant difference between the protocols.
PMID: 22147680 [PubMed – indexed for MEDLINE]