Background It is generally accepted that strength and muscle mass can be increased by strength training programs. Results are known to depend on training volume and training intensity.^{1 2} Strength increases when performing sets to the Repetition Maximum (PM) or even to the point of momentary muscular failure (PmF) and muscle hypertrophy has been proven to be superior to the results of sets performed at lower levels of intensity.^{3 4}

Methods In this study (n=43) subjects trained twice a week for ten weeks. One group performed high-intensity training (n=16) and did only one drop-set of each exercise to the point of momentary muscular failure (HIT), whereas the other group (n=14) performed as many repetitions as possible in each set and did three sets of each exercise (3ST). The control group (n=13) did not strength train at all. The body composition of all groups was analysed in weeks 0 and 11. Subjects also performed strength tests for nine exercises in weeks 0 and 11.

Results Strength tests and bioelectrical impedance analysis (Tanita MC 180, MA) show increased strength and muscle mass in both training groups but not in the control group.⁵ However, both strength and muscle mass increased to a greater extent in HIT than in 3ST. After ten weeks of training HIT increased the maximum number of repetitions in the nine test exercise by an average of 25 (15.7/40.3) repetitions per exercise while 3ST increased repetitions by an average of only 15 (6.4/24) repetitions per exercise. Furthermore, HIT increased to a significantly greater extent than 3ST while simultaneously decreasing body fat.

Discussion/Conclusions One set of HIT is sufficient to improve muscle mass and strength. On average, results over a training period of ten weeks are better than those of 3ST. Further studies are needed to examine the effects of HIT and 3ST training periods longer than ten weeks.