Strength Dose-Response Curve
Trained participants experience maximal strength gains training each muscle group 2 days per week with an average training intensity of 80% of their 1 RM, or approximately 8 RM. Four sets performed per muscle group elicited the most gains in both trained and untrained. Interestingly, only marginal benefits were observed between 2 and 4 sets per muscle group in trained individuals.
Rhea warns their dose-response curves represent mean training levels and should not be construed as supporting training at a particular volume or intensity on a constant basis. Instead, effective programs should incorporate varied training doses (volume, frequency, and/or intensity) [particularly for trained individuals].
Untrained participants (less than 1 year of consistent training) experience maximal strength gains with an average training intensity of 60% of their 1 RM or approximately a 12 RM, training each muscle group 3 days per week. Novices weight training 2 times per week may make approximately 80% of the strength gains as compared to training 3 times per week.
Rhea et al (2003) suggested caution when prescribing multiple-set programs to those who have not been training consistently for at least 1 year. Adequate time is required to become accustomed to the stress of resistance exercise and avoid over-stress injuries in the early phases of training. Novice trainees may also lack the desire to commit to a training program requiring the additional time needed to perform multiple sets and thus reduce adherence to the exercise regimen.
Braith RW, Graves JE, Pollock ML, Leggett SL, Carpenter DM, Colvin AB (1989). Comparison of 2 vs 3 days/week of variable resistance training during 10- and 18-week programs. Int J Sports Med. 10(6):450-4.
Rhea MR, Alvar BA, Burkett LN, Ball SD (2003). A meta-analysis to determine the dose response for strength development. Med Sci Sports Exerc. 35(3):456-64.
Ahtiainen et. al. compared 2 to 5 minute rest periods in previously strength-trained men. No significant difference in acute hormonal and neuromuscular responses or long-term training adaptations in muscle strength and mass were found.
Ahtiainen JP, Pakarinen A, Alen M, Kraemer WJ, Häkkinen K (2005). Short vs. long rest period between the sets in hypertrophic resistance training: influence on muscle strength, size, and hormonal adaptations in trained men. J Strength Cond Res.19(3):572-82.
3 minute rests between sets of bench press allowed for more repetition to be performed than rests of 2 or 1 minute.
Willardson JM, Burkett LN (2006). The effect of rest interval length on bench press performance with heavy vs. light loads. J Strength Cond Res. 20(2):396-9.
Squat strength gains were not significantly different between 2 minutes versus 4 minutes rest between sets.
Willardson JM, Burkett LN (2008). The effect of different rest intervals between sets on volume components and strength gains. J Strength Cond Res. 22(1):146-52.
Light activity between sets can improve recovery. In a study conducted at University of Kansas, subjects completed six sets of squats (85% 10RM) with 4 minute rest periods between sets. Rest periods consisted of either sitting quietly (passive recovery) or cycling at 25% or 50% of VO2max (active recovery). Blood lactate was significantly lower when cycling at 25% of VO2max compared to the other two types of rest periods. Following the initial workout, the 25% VO2 recovery group continued to perform more repetitions to exhaustion (65% if 10RM) compared to the other two recovery groups. Also see Dodd (1984).
Corder K, Potteiger J , Nau K, Figoni S, Hershberger S (1998). Effects of active and passive recovery on lactate, RPE, and performance during resistance training. Medicine and Science in Sports and Exercise, 30(5), Supplement abstract 194.
Corder KP, Potteiger JA, Nau KL, Figoni SE, Hershberger SL (2000). Effects of active and passive recovery conditions on blood lactate, rating of perceived exertion, and performance during resistance exercise. Journal of Strength and Conditioning Research, 14: 151-156.
Gentil (2013) found no statistically significant additional size or strength gains in untrained young men when including isolated exercises in a program of compound exercises. 29 untrained young men participated in a 10 week training program of either only compound exercise (Pulldown and Bench Press) or a combination of compound and isolated exercises (Pulldown, Bench Press, Arm Curls, and Triceps Extensions). Muscle size as measured by ultrasound increased significantly in both groups (Compound Only 6.5%; Combination 7.04%) as did strength as measured by peak torque (Compound Only 10.4%; Combination 12.85%) but no statistically significant differences were seen between groups for either muscle size or strength.
Gentil P1, Soares SR, Pereira MC, Cunha RR, Martorelli SS, Martorelli AS, Bottaro M (2013). Effect of adding single-joint exercises to a multi-joint exercise resistance-training program on strength and hypertrophy in untrained subjects. Appl Physiol Nutr Metab. 38(3):341-4.
Making workload alterations (8RM, 6RM, 4RM) every workout was more effective in eliciting strength gains than doing so every 4 weeks.
Rhea MR, Ball SD, Phillips WT, Burkett LN (2002). A comparison of linear and daily undulating periodized programs with equated volume and intensity for strength. J Strength Cond Res. 16(2):250-5.
Hunter et. al. compared variable resistant training (once-weekly training at 80%, 65%, and 50% 1RM) versus training 3 times a week at 80% 1RM in men and women over the age of 60. After 6 months, both groups made similar strength and lean body mass gains. However, the variable resistant training group reported lower perceived exertion during a carrying task.
Hunter GR, Wetzstein CJ, McLafferty CL Jr, Zuckerman PA, Landers KA, Bamman MM (2001). High-resistance versus variable-resistance training in older adults. Med Sci Sports Exerc. 33(10):1759-64.
Painter et. al. compared daily undulating periodization (DUP) versus a block periodization during a 10 week study. Although no statistically significant differences in strength and rate of force development were found between the two training groups, the block periodization group performed less volume of work (35% less volume load) and consequently greater improvements per volume load. Based on these training efficiency scores, the authors concluded that a block training model was more efficient than a DUP model in producing similar strength gains. The authors discussed the less work during the tapering period of the block periodization in contrast to the accumulative fatigue presumably experienced by subjects using the DUP. It is intersting to note that both training protocols varied workloads at least nearly every workout (repetition range variations for DUP and percent 1RM variations for Block Training). Also the Block Training program included the Power Snatch and volume tapering, whereas the DUP program included neither for seemingly unexplained reasons.
Painter KB, Haff GG, Ramsey MW, McBride J, Triplett T, Sands WA, Lamont HS, Stone ME, Stone MH (2012). Strength gains: block versus daily undulating periodization weight training among track and field athletes. Int J Sports Physiol Perform. 7(2):161-9.
See sample programs based on varying workloads: