The squat is one of the most widely used exercises in resistance training programs. The aim of this narrative review was to analyze the effect of the squat on lower-limb muscle hypertrophy. Briefly, the available literature indicates that the squat is an effective exercise for inducing hypertrophy of the quadriceps, mainly the vastii, but also the rectus femoris, although to a reduced magnitude. Multiple lines of evidence suggest little to no hamstring hypertrophy from the back squat. Although the gluteus maximus clearly participates mechanically in the back squat, few longitudinal studies exist on the topic. The limited evidence available on this topic suggests deeper squats may be more hypertrophic for the gluteus maximus, and that, squat depth beyond 90° of knee flexion may not provide further hypertrophy of the knee extensors. Despite the popularity of the many squat variations, there are still controversies surrounding their hypertrophic potential for lower-limb musculature. Further studies are needed to investigate the hypertrophic effects of different squat variations, as well as differences in hypertrophy because of squat depth, stance, barbell position, and different squat apparatuses/machines.

The main purpose of the present study was to investigate the acute effects of different training loads on ratings of perceived exertion and discomfort and feelings of pleasure/displeasure in resistance-trained men. Twelve resistance-trained men (26.7±3.5 years, 85.1±17.5 kg, and 174. 9±9.9 cm) performed 3 sets of the bench press, squat on a hack machine, and lat pulldown, until volitional concentric failure in two separate conditions: a moderate load (MOD) consisting of a relative load of 8–12 repetitions maximum (RM), and a light load (LIT) consisting of a relative load of 25–30RM. The session rating of perceived exertion (sRPE), session rating of perceived discomfort (sRPD), and session pleasure/displeasure feelings (sPDF) were assessed after 15 min after the ending of each session. A randomized, counterbalanced, crossover study was performed with 48 h recovery afforded between sessions. Differences between conditions were observed for sRPE and sRPD, in which scores for LIT were greater than MOD (sRPE: MOD=5.5±1.0 vs. LIT=6.4±0.7; sRPD: MOD=6.7±1.7 vs. LIT=8.7±1.0). For sPDF, MOD reported feelings of pleasure (1.2), whereas the LIT presented a feeling of displeasure (–2.3). Results suggest that resistance training performed with a light load until failure induces higher degrees of effort, discomfort and displeasure compared to a moderate load.