(41) THE EFFECTS OF PULSED ELECTROMAGNETIC FREQUENCY (PEMF) THERAPY ON RECOVERY FROM STRENUOUS EXERCISE IN COLLEGE-AGED MEN AND WOMEN

Abstract Details: Recovery from intensive exercise is essential for athletes. Consequently, many use novel modalities to aid this process. One example is pulsed electromagnetic field (PEMF) therapy, which involves a device that emits low frequency electromagnetic currents that may affect cell function.

Purpose: To detail whether PEMF therapy enhances recovery after fatiguing exercise.

Methods: Thirty-three (19 men, 14 women) college-aged subjects were allocated to one of three groups: PEMF (subjects received 22:32 min:s of PEMF therapy while holding the device); PLAC (placebo; subjects held a device that was not on for 22:32 min:s); and CONT (control; subjects sat for 22:32 min:s). Fatigue was induced by a 3-stage Yo-Yo running protocol. Recovery interventions were provided immediately after the fatigue protocol (0 hours), and 24, 48, and 72 hours post-fatigue protocol. Recovery was measured quantitatively by a 6-s peak power (PC) and cadence (PC) test on a cycle ergometer; vertical jump (VJ); and isometric leg/back dynamometer strength (LBD). These were taken at baseline (prior to fatigue protocol), immediately after the 0-hour recovery intervention, and after the interventions at 24, 48, and 72 hours. Qualitative recovery was measured by visual analogue and Likert scales pre and post each recovery intervention. A 3 (PEMF, PLAC, CONT) x 5 (baseline, 0, 24, 48, 72 hours) repeated measures ANOVA, with sex as a covariate, derived any between-group differences. Change scores relative to the baseline were calculated, and analyzed by a 3 x 4 (0-baseline, 24-baseline, 48-baseline, 72-baseline) repeated measures ANOVA. Paired samples t-tests compared the qualitative measures pre and post recovery intervention. A 3x8 and 3x4 repeated measures ANOVA calculated any differences in perceived recovery and the pre-post change scores.

Results: There were no significant time by group ANOVAs. The main effects for time for PP and PC, and the change scores, were significant. PP (p≤0.005) and PC (p< 0.001) at 0 hours were generally lower than at all other times. The PP and PC 0-baseline change scores were lower compared to change scores from the other time points (p< 0.001). Although not significant, the PEMF group had greater change scores for PP, VJ, and LBD compared to the other groups, especially at 24 hours (Figure 1). There was a significant decrease (p=0.003; d=0.707) in the PEMF group Likert scale score at 24 hours.

Conclusions: Although no significant differences in recovery between the groups were observed, change score and qualitative data suggested that the device used by the PEMF group had a positive influence on recovery and PP, VJ, and LBD performance 24 hours post fatigue protocol. Large standard deviations in the data suggest variation in individual responses. PRACTICAL APPLICATIONS: PEMF therapy may be beneficial to help with recovery from strenuous exercise among some individuals. Research is needed to ascertain mechanisms for how PEMF therapy could affect recovery.

Acknowledgements: Equipment for this research was provided by HAELO (Encino, CA, USA).