If you do strength training to improve your sports performance or your general physical functioning in every day life, you can forget about leg-presses. Rather than wasting your time on the leg-press machine you would do better to concentrate on squats. We base this bold statement on a study that the German sports scientist Klaus Wirth published in the Journal of Strength and Conditioning Research.
The researchers divided almost 80 students into three groups. The first group, the control group, did nothing for eight weeks.
Training your legs on the leg-press? Squats are better…
A second group of students trained their legs on a leg-press machine twice a week for eight weeks; and a third group trained their legs by doing squats. The two training groups used the same training schedule.
The students who had done squats boosted their maximal strength while squatting by about a quarter. The students who had trained on the leg-press also boosted their maximal strength by a quarter while doing leg presses.
The researchers measured the amount of isometric strength the subjects could generate on a kind of leg-extension machine, before and after the training period. They also got the students to do jump squats and countermovement jumps so that they could measure – put simply – the speed the students were capable of developing.
The subjects who had done squats made progress in all three areas. The subjects that had trained on the leg-press machine made virtually no progress at all.
So the strength you develop by squatting results in and increase in strength and speed when doing real life movements. The strength that is built up by doing leg-press exercises does not have the same effect.
“The data suggest a large influence of the selection of training exercise on performance improvement – at least short-term”, wrote the researchers. “The squat was shown to be the more effective training exercise. Therefore, it should be preferred to the leg press.”
“This holds true especially in the special stage before competition because of the better transfer effects on jumping performance but must also be considered in the context of long-term development of speed-strength performance.”
The Impact of Back Squat and Leg-Press Exercises on Maximal Strength and Speed-Strength Parameters
Abstract: Wirth, K, Hartmann, H, Sander, A, Mickel, C, Szilvas, E, and Keiner, M. The impact of back squat and leg-press exercises on maximal strength and speed-strength parameters. J Strength Cond Res 30(5): 1205–1212, 2016—Strength training-induced increases in speed strength seem indisputable. For trainers and athletes, the most efficient exercise selection in the phase of preparation is of interest. Therefore, this study determined how the selection of training exercise influences the development of speed strength and maximal strength during an 8-week training intervention. Seventy-eight students participated in this study (39 in the training group and 39 as controls). Both groups were divided into 2 subgroups. The first training group (squat training group [SQ]) completed an 8-week strength training protocol using the parallel squat. The second training group (leg-press training group [LP]) used the same training protocol using the leg press (45° leg press). The control group was divided in 2 subgroups as controls for the SQ or the LP. Two-factorial analyses of variance were performed using a repeated measures model for all group comparisons and comparisons between pretest and posttest results. The SQ exhibited a statistically significant (p ? 0.05) increase in jump performance in squat jump (SJ, 12.4%) and countermovement jump (CMJ, 12.0%). Whereas, the changes in the LP did not reach statistical significance and amounted to improvements in SJ of 3.5% and CMJ 0.5%. The differences between groups were statistically significant (p ? 0.05). There are also indications that the squat exercise is more effective to increase drop jump performance. Therefore, the squat exercise increased the performance in SJ, CMJ, and reactive strength index more effectively compared with the leg-press in a short-term intervention. Consequently, if the strength training aims at improving jump performance, the squat should be preferred because of the better transfer effects.