For as long as I can remember, coaches and fitness professionals have debated the merits of single versus multiple-set strength training. I have personally trained in both manners, and I have conducted numerous research studies on the effects of single and multiple-set exercise protocols. In all of my experiences and experiments, I have found no significant differences between these two training methods.

Consider our most frequently referenced study with 77 intermediate level strength participants who trained 3 days a week for 10 weeks with assisted bar-dips (pectoralis major, anterior deltoids, and triceps muscles) and assisted chin-ups (latissimus dorsi, and biceps muscles). Group One did 1 set of bar-dip and 1 set of chin-ups, Group Two performed 2 sets of bar-dips and 2 sets of chin-ups, and Group Three completed 3 sets of bar-dips and 3 sets of chin-ups. Groups Two and Three rested 2 minutes between successive sets of each exercise.

After 10 weeks of training, all three groups were assessed for their improvement in bar-dip and chin-up performance, tested with bodyweight. Group One experienced an average bar-dip/chin-up increase of 4.8 repetitions, Group Two increased their average bar-dip/chin-up score by 4.1 repetitions, and Group Three had an average improvement of 5.2 bar-dip/chin-up repetitions. Statistically, there were no significant differences among the single, double and triple-set training protocols.

A classic follow-up study conducted at the University of Florida revealed similar results. After 14 weeks of strength training the knee extension and knee flexor muscles with leg extensions and leg curls, the 38 subjects recorded almost identical average strength gains regardless of performing 1 set or 3 sets of each exercise (14.5% increase vs. 15.5% increase).

Although dozens of other studies have shown similar strength benefits from single and multiple set training, a recent meta-analyses of more than 100 studies indicated that 4 sets of exercise (targeting a specific muscle group) may be the most effective strength-building protocol. Ignoring the methodological problems associated with meta-analyses, performing 4 sets of each exercise presents two practical problems for many people, namely time availability and physical ability.

For example, time-pressured men and women may have difficulty spending approximately 10 minutes at each exercise station (4 sets of 1 minute each with 2 minutes recovery time between sets). At this rate, 12 exercises would require about 2 hours for completion, compared to about 25 minutes for a single-set training protocol.

For others, particularly previously sedentary, deconditioned, and elderly individuals, 4 sets of each exercise may be simply too physically demanding. Although they may be able to gradually progress to higher volume training programs, they would be well-advised to begin with 1 good set of each exercise.

Our research with more than 1100 beginning participants (previously inactive adults between 20 and 80 years of age) featured 1 set (8 to 12 repetitions) of 10 exercises, performed 2 or 3 days a week for a period of 8 weeks. This 20 minutes per session strength training program has produced significant increases in lean (muscle) weight and significant decreases in fat weight. As shown in Table 1, the men averaged almost 4 pounds more lean weight and 7 pounds less fat weight, and the women averaged almost 2 pounds more lean weight and 4 pounds less fat weight. These results compare favorable with all other published studies on beginning strength training, regardless of the number of sets or exercises performed.

Table 1. Body composition changes following 8-weeks of single-set strength training (1132 subjects).

As participants continue training, they eventually encounter a strength plateau. When single-set exercise sessions no longer elicit further progress in strength or muscle development, a change in the training protocol becomes necessary. One means for increasing the training stimulus is a higher volume exercise program involving more sets, more exercises, or both. At this point, in their training, participants should be capable of performing higher volume strength training sessions, but they may not have the time to do so.

If time constraints prohibit multiple-set training, plateaued participants can enhance their single-set exercise sessions with high-intensity training techniques. Generally, these advanced training procedures require a few post-fatigue repetitions immediately following your standard exercise set. This is typically accomplished through breakdown repetitions (reducing the resistance by 10 to 20% at the point of temporary muscle failure and completing as many additional repetitions as possible) or assisted repetitions (having a partner assist in the lifting phase of additional repetitions upon experiencing temporary muscle failure).

Although adding less than 30 seconds to the extended exercise set, high-intensity training techniques have proved highly effective in our studies for the U.S. Navy. In the athletic arena, 12 of the professional football teams in the NFL presently use single-set, high-intensity strength training protocols.

Although essentially everyone should do strength training, relatively few people really enjoy doing it. If you are like me, you look forward to every strength workout, but we are definitely in the minority (a reasonable estimate is that about 5 to 10 percent of Americans do some form of strength exercise). While we would be perfectly happy spending a couple hours a day in the weightroom, most of us just don’t have the time to do so. Fortunately for us, and for all those who don’t particularly like either free-weights or weightstack machines, single-set training (alone or with high-intensity techniques) offers a safe, effective, and time-efficient option for strength and muscle development.