Dose-response relationship for size and strength: 5, 3 or 1 set?

When the goal is to increase hypertrophy and strength levels, it appears that training volume may be a key factor. Over the years there has been great debate between whether individuals should perform 1 set or 3 sets for increasing strength and muscle mass. Review papers on the topic tend to favor multiple sets over single sets. This certainly isn’t to say that single sets aren’t effective, just that multiple sets are likely more effective. Less understood is the effect of even more sets on strength and hypertrophy. If 3 sets are better than 1, would 5 sets be even better?

Some new research out of Brazil by Radaelli et al. (2014) published in the Journal of Strength and Conditioning research endeavored to determine if longitudinal training using 1, 3, or 5 sets resulted in any differences in strength and hypertrophy gains. Forty-eight men (~24 years old) from the Brazilian Navy School of Lieutenants were split into a 1-set group, 3-set group and 5-set group and a control group. The soldiers all had experience with calisthenic type training (push ups, sit-ups, etc.) but did not have a resistance training background.

Over the course of 6 months, the subjects trained 3 times per week (95% compliance). The workout structure involved full body workouts on exercise machines including: bench press, leg press, lat pull down, leg extension, shoulder press, leg curl, biceps curl, crunches and triceps extensions. All groups performed 8-12 reps to concentric failure. Weight was increased by 5-10% whenever 12 reps were achieved in all sets for an exercise. 90-120 seconds rest was provided between sets.

Before and after the training program, 5RM’s, 20RM’s, vertical jump, body fat (skin-fold thickness), upper arm muscle thickness (ultra-sonography) was assessed for all groups. The table lists which groups made the most progress.

The authors conclude that there is a dose response relationship between training volume and gains in strength, endurance and body composition. Compared to week 1, training volume completed increased by (approximately) 22,000 kg for the 5-set group, 17,000 in the 3-set group and 9,000 in the 1-set group. It is quite clear the the 5-set protocol was the most effective at improving performance markers.

One of the drawbacks of the 5-set protocol is the additional time that is required to complete the workouts. However, if time permits, performing 5 sets over 3 or 1 may yield superior results in the long term.

Reference:

Radaelli, R., Fleck, S. J., Leite, T., Leite, R. D., Pinto, R. S., Fernandes, L., & Simão, R. (2014). Dose Response of 1, 3 and 5 Sets of Resistance Exercise on Strength, Local Muscular Endurance and Hypertrophy. Journal of Strength and Conditioning Research. Ahead of print.