Myomuscle

Post processing of data occurred in myoMUSCLE™ (Noraxon, Scottsdale, AZ, USA). EMG signals were filtered using a band‐pass filter (Butterworth, 40 and 450 Hz cutoffs) following current recommendations (St. George et al., 2018 (link)). Peak amplitude over a 100 ms duration during social isolation was determined and used for normalization. EMG signals were rectified and then normalized to the peak value obtained previously. The frequency content of the EMG signal was determined using a Fast Fourier transformation (FFT) (myoMUSCLE™, Noraxon, Scottsdale AZ, USA). The average rectified value (ARV, %) and median frequency (MF, Hz) were calculated (myoMUSCLE™, Noraxon, Scottsdale AZ, USA) for the first 30 s (0–30 s), middle 30 s (75–150 s), and final 30 s (150–180 s) of each treatment period.

Muscle activity during strength and fatigue testing was recorded via a wireless EMG system (Ultium-EMG, Noraxon USA Inc., Scottsdale, AZ, USA). EMG electrodes were placed bilaterally over the rectus femoris, vastus medialis, vastus lateralis, and semitendinosus according to a 3D Muscle Map provided by the EMG software (MR 3.14, myoMUSCLE, Noraxon USA Inc., Scottsdale, AZ, USA) that followed SENIAM guidelines. Site preparation included shaving leg hair and vigorously scrubbing with an alcohol wipe before placing the EMG electrodes (3M Red Dot Monitoring Electrode, Model 2560; 3M Corp., St. Paul, MN, USA; 2 cm between each 1.3 cm effective area). Once the electrodes and wireless transmitters were in place, they were secured with elastic bandages. EMG data were collected at 2000 Hz.