“As we exercise and challenge our muscles, we cause breakdown within the muscle fibers, which in turn stimulates muscle growth/regrowth, hypertrophy (increase muscle size) and strength,” said Jacklyn Plonski, an outpatient orthopedic and pediatric physical therapist. “Mechanical stimulation of a muscle [with a device like the Theragun] causes increased blood flow and the release of histamines to the stimulated area. What this does is allow the increased blood flow to decrease the inflammatory response, decrease muscle soreness, and break up knots in athlete’s musculature.” She likened this technique to using a foam roller or getting a professional treatment done.
Shelby Milne, an athletic trainer at UPenn, said that the athletes there swear by Theraguns and have used them for both pre- and post-training (they currently use a different brand of percussive therapy devices). “The oscillations can also act as a warming modality for the muscles and tissues before the activity,” she said.
While Plonksi has seen anecdotal evidence supporting the use of a Theragun, and no apparent negative effects, she recommends always talking to your medical provider first before starting a regimen like this.