Timing-Dependent Neuromuscular Responses to Pulsed Electromagnetic Field (PEMF) Stimulation During Cycling Exercise...

Pulsed electromagnetic field (PEMF) increases the amplitude of muscle activity during physical exercise. This study investigated the effects of PEMF stimulation timing on neuromuscular activation in young sedentary males, during moderate-intensity constant-load cycling. We examined whether a PEMF applied at the beginning or during the middle of continuous exercise elicits differential effects on muscle activation. The participants performed a 30 min cycling task at 50% of VO₂max in which PEMF stimulation was alternately activated or deactivated in 15 min bouts. Surface electromyography (EMG) was recorded from the right vastus medialis and biceps femoris, and blood lactate samples were collected at baseline and during exercise. Data were analyzed via linear mixed-effects modeling. Active PEMF stimulation significantly increased normalized EMG amplitude in the vastus medialis (p < 0.001) and biceps femoris (p = 0.001) compared to inactive conditions, with the greatest effect observed when stimulation was applied after 15 min of exercise. Blood lactate concentrations were significantly elevated during PEMF application relative to baseline and inactive stimulation (p < 0.001). The timing of PEMF stimulation influenced neuromuscular responses during exercise, highlighting its potential as a tool to modulate muscle performance in sedentary individuals.