Effects of Pulsed Electromagnetic Field Application on Aerobic Performance in Runners During Short-Term Altitude Training

Abstract

Pulsed Electromagnetic Field (PEMF) application increases microcirculation throughout the body and has been shown to be beneficial in clinical populations. In athletic populations, PEMF is used to improve recovery. Altitude training has long been used by endurance athletes to improve sea-level performance. PURPOSE: To determine if recovery with PEMF during altitude performance leads to greater improvements in VO2Peak, and ventilatory threshold (VT) in cross-country runners. METHODS: Fourteen male NCAA cross-country runners (age: 19.07±0.92 y.o.) with initial VO2Peakof 73.13 ± 5.65 ml/kg/min participated in the study.Subjects were randomly assigned either to the PEMF intervention (INT) (n=8) or to a control group (CON) (n=6). VO2Peakand VT were evaluated using a metabolic cart at sea-level, pre- and post-training. Runners from sea level traveled to high altitude where they lived at 1322m above sea-level for 6 days. Six training sessions were performed at altitudes ranging from 881.25±148.87m to 1047.70±237.29m above sea-level with training sessions averaging a duration of 75.25±7.04 mins, speed of 13.02±1.60 kmph and distance of 16.42±2.95 km. Subjects in INT received PEMF application prior to and after training, while subjects in CON did not. RESULTS: There was no significant difference in either absolute or relative VO2Peak. A main-effect of time was found for absolute VT (p<0.01), which changed from 3.35±0.52 L/min to 3.89±0.55 L/min, and VT relative to VO2Peak(p<0.01), which changed from 73.10±1.60% of VO2Peak to 87.08±1.82% of VO2Peak. There was no significant difference between groups for absolute VT (p=0.24) however, the INT group displayed a positive-trend for VT relative to VO2Peak(INT: 18.28%, CON: 9.68%; group*time p=0.07). Consequently, there was a main effect of time for heart-rate at VT (p=0.02), which changed from 168.10±3.25 bpm to 175.34±3.49 bpm, with no difference between groups (group*time p=0.11). CONCLUSION: While altitude training showed some positive adaptations in cross-country runners, the addition of PEMF did not improve these adaptations significantly. This can be attributed to the short duration of application, since a positive-trend was found for VT relative to VO2Peak. PEMF could have beneficial effects when combined with a longer duration of altitude training.