Different physiological and perceptual parameters responses to six squat exercise variations

With the use of high-precision wearable devices to monitor internal load increasing exponentially (Seshadri, 2019), objective measures, heart rate (HR) and muscle oxygen saturation (SmO2), and subjective measures, rate of perceived exertion (RPE) are widely used in the context of resistance training for the differentiated information they provide. This study compared the effects of six body-weight squat variations on HR, SmO2, and RPE. Fourteen healthy recreational trained participants (age=28.8±7.6 years old; height=1.72±0.07 m; weight=71.9±10.3 kg) underwent two testing sessions: a familiarisation session, and an experimental session where all exercises were performed in a randomised order. The six variations of the squat were 1) deep, 2) jump, 3) wall-sit, 4) uneven, 5) single-leg, and 6) unstable. Each variation was performed for 90 seconds, with five minutes of passive recovery between variations. Two near-infrared spectroscopy devices fixed on the vastus lateralis (VL) and on the soleus (SL) muscles, and a HR monitor were used to assess SmO2 and HR, respectively. RPE was registered immediately after each exercise. The average HR (HR avg), average SmO2 (SmO2 avg), amplitude of deoxygenation (SmO2 deoxy), and RPE were determined. A one-way ANOVA (repeated measures) was applied, followed by the Bonferroni post hoc pair-wise comparisons. Statistical significance was accepted at p