Are three sets necessary to optimise your strength?
It’s as regular and straightforward as tying your shoes: when you go to the gym you complete three sets of each of your chosen strengthening exercises – not just one or two, and not as many as four. Three is the magic number – the quantity of sets which will optimise your strength gains over time. Whether you are bench-pressing, leg-pressing, biceps-curling, hitting lat pull-downs or performing any other kind of resistance exercise, three sets must be performed before you can consider your routine complete.
In research carried out at the University of Florida, 42 adult weightlifters with a mean of six years of weight-training experience were divided into two groups, one performing one set of a nine-exercise resistance-training circuit three times a week for 13 weeks, and the second performing three sets of the same circuit at the same frequency for the same period of time. For each of the exercises, including leg extensions, leg curls, chest presses, overhead presses and biceps curls, 8-12 repetitions were performed to muscular failure; (that is, the resistance for each drill was set so that subjects could complete at least eight reps but not more than 12, and the intensity could thus be called 8-12 rep max).
After 13 weeks, both groups had significantly improved muscular endurance while doing chest presses and leg extensions (muscular endurance being defined as the number of repetitions to failure, using 75% of the pre-training 1-rep max for each exercise). Both groups also significantly improved 1-rep max strength for the five key exercises and significantly enhanced lean body mass.
The key finding, however, was that the one-set lifters improved all three characteristics just as much as those who put in three times as much work!
Citing findings such as these, one-set supporters like to tell multi-set trainers that they would be better off limiting themselves to just one set of any single exercise, then moving on to another one designed to produce a different type of sport-specific strength, rather than yoking themselves to unproductive repetitions of a limited number of movement patterns.
However, it should be noted that not all research is so supportive of one-set strength training. In a recent study by one of the most respected figures in strength-training research, Dietmar Schmidtbleicher of Johann Wolfgang Goethe University in Frankfurt am Main, Germany, three sets proved superior to one. In this investigation, 27 experienced female strength-trainers were randomly assigned to a single-set group, a three-set group, or a non-training control group. Both of the training groups took part in a whole-body strengthening programme, working out twice a week for six weeks with such exercises as bilateral leg extensions, bilateral leg curls, abdominal crunches, seated hip adductions/abductions, seated bench presses and lateral pull-downs. The single-set group performed one set of 6-9 repetitions to failure of each exercise per workout, while the three-set group completed three sets per workout at the same intensity; the rest interval between sets was two minutes.
Studies support three-set training
In a more recent investigation from Arizona State University, three-set training also emerged a clear winner. In this study, 16 experienced strength-trainers were equally divided into one-set and three-set groups, both of which trained three times a week for 12 weeks. One-repetition maximums were recorded for all athletes for both the bench press and leg press before the study began, midway through the investigation and after 12 weeks of training.
The subjects focused on the bench press and leg press during their training, using an undulating-periodisation pattern (see lead article, p1) and intensities of 4-rep and 8-rep max. After 12 weeks, the three-set trainers had upgraded their leg-press 1-rep max strength by 56%, from 226 to 344kg, while the one-set athletes had improved by just 26%, from 269 to 337kg – a statistically-significant difference. For the bench press, three-set athletes upped 1-rep max strength by 16% over the second half of the 12-week period, while the one-set group managed only a 3% improvement – also a statistically significant difference.
What are we to believe? Bear in mind that the one-set v three-set controversy cuts to the heart of the basic question about which aspect of exercise actually stimulates muscles to adapt in ways which boost their strength. One theory is that training at high intensity (ie with high muscle tension) is the key trigger for improving maximum strength. This being the case, the number of sets completed would be of relatively minor importance, since exposure of muscles to high tension could easily be accomplished with one set.
However, many exercise physiologists believe that maximisation of strength also hinges on the creation of some sort of fatigue stimulus within muscles. In support of this principle, research has shown that long, fatiguing isometric contractions produce greater gains in maximum strength than shorter, less-fatiguing isometric contractions, even when the time duration of muscle activity is equivalent. For example, one study found that four highly fatiguing 30-second contractions induced greater maximum strength than 40 three-second contractions of the same muscle group, even though the amount of time in contraction was exactly the same in both cases.
Fatigue helps build maximum strength
An ingenious recent study also supported the induction-of-fatigue mechanism for creating maximal strength. To hasten fatigue in the muscles undergoing strength training, scientists actually applied tourniquets to the subjects’ limbs, so producing ischemia (reduced blood flow) in the working muscles. Four weeks of training with tourniquets (and thus reduced blood flow to the active muscles) did not compromise the gains in strength achieved by the muscles; in fact, the muscles with tourniquet-restricted blood supplies (and thus, in theory, the greatest amount of fatigue) actually made greater strength gains than those with normal blood flow!
These latter studies support the notion that three-set strength training is superior to one-set work, since fatigue levels would be higher in the former. Indeed, although research findings are inconsistent, the scientific scales seem to be tipping in the three-set direction. Thus it would seem reasonable to persist with – or shift to – three-set training. Three sets can provide muscles with sufficient intensity and fatigue to induce the greatest possible enhancements in maximal strength.