Physiother Res Int. 2011 Dec 7. doi: 10.1002/pri.527. [Epub ahead of print]
Comparison of Two Resistance Training Protocols, 6RM versus 12RM, to Increase the 1RM in Healthy Young Adults. A Single-Blind, Randomized Controlled Trial.
Aarskog R, Wisnes A, Wilhelmsen K, Skogen A, Bjordal JM.
Purpose. 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). Method. 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. Interventions. 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. Results. 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. Conclusion. Both 6RM and 12RM training protocols improve maximum strength in recreationally active healthy young adults, with no significant difference between the protocols.