Photobiomodulation by light emitting diode applied sequentially does not alter performance in cycling athletes

Area of Science:

• Sports Medicine
• Exercise Physiology
• Biomedical Engineering

Background:

• Photobiomodulation therapy (PBMT) utilizes light to influence cellular processes.
• Different wavelengths of light may have varying effects on physiological responses and athletic performance.
• The sequential application of PBMT in athletes requires further investigation.

Purpose of the Study:

• To analyze the effects of sequential PBMT at different wavelengths on cycling performance.
• To compare the efficacy of infrared, red, and combined red/infrared PBMT against a sham intervention.
• To evaluate PBMT's impact on physiological and biomechanical parameters in cyclists.

Main Methods:

• Forty-eight male cyclists underwent performance evaluations including incremental tests, VO2max, lactate analysis, and isokinetic assessments.
• PBMT (180 J) with infrared (IR), red (RED), or combined RED/IR wavelengths, or sham, was applied to quadriceps bilaterally over three consecutive days.
• Reevaluations occurred 24 hours post-intervention, with a one-week follow-up; effect size (Cohen's d) was calculated.

Main Results:

• No statistically significant differences were found across all variables for any condition (p > 0.005).
• Moderate to considerable effect sizes were observed for isokinetic torque and power in the combined RED/IR group compared to sham.
• Large effect sizes were noted for time to exhaustion and VO2max, and a moderate effect for anaerobic threshold in the RED/IR group versus sham.

Conclusions:

• PBMT alone, without concurrent training, did not yield significant cumulative performance effects in cycling athletes.
• The combination of red and infrared wavelengths demonstrated a promising trend for enhancing cycling performance metrics.
• Further research is warranted to optimize PBMT protocols for athletic performance enhancement.