Author(s): BELMONTE, G., GERVASI, M., PATTI, A., FORMIGLIO, E., PIRAS, S.I., DI MITRI, I.R., BIANCO, A. FERNÁNDEZ-PEÑA, E., Institution: UNIVERSITY OF PALERMO, Country: ITALY, Abstract-ID: 1732

INTRODUCTION:
Far-infrared (FIR)–emitting textiles have been proposed as a passive strategy to modulate thermoregulation and reduce cardiovascular strain during endurance exercise [1]. In this context, the choice of textile fiber has been shown to significantly influence thermoregulatory efficiency and perceived comfort during cycling performance at a temperate condition [2]. This randomized crossover study investigated the acute effects of a full-body FIR garment compared to a placebo during cycling at ventilatory threshold 1 (VT1), accounting for environmental variability.
METHODS:
Nine junior and one Under 23 male cyclists (17.4 ± 1.4 years; VO₂max 67.9 ± 3.5 ml·kg⁻¹·min⁻¹) completed standardized sessions including 40 min at VT1 and a 5-s maximal sprint. Heart rate (HR), skin temperature, core temperature, peak and area under curve (AUC) temperature, VO₂ mean, gross efficiency, hydration markers, perceived comfort and hematological variables were collected. Repeated-measures ANCOVA (within factor: garment) was performed using mean room temperature and relative humidity as covariates. Partial eta squared (ηp²) was calculated. Time-series variables were analyzed using linear mixed models (LMM) with garment × time interaction and environmental covariates.
RESULTS:
Mean room temperature across sections was 21.04; humidity 58.57. HR mean and HR AUC were significantly lower with FIR (respectively, Δ ≈ −4.2 bpm; Δ ≈ −158 bpm·s; p < 0.005, ηp²=.453), indicating reduced cardiovascular strain. Core temperature peak and AUC were significantly lower with FIR (Δ ≈-0.1; p < 0.05; ηp²=.378), whereas skin temperature peak was slightly higher. VO₂ mean, gross efficiency and sprint peak power were unaffected (p > 0.05). No clear differences were observed in body mass loss, hematocrit, hemoglobin or plasma volume variation (p > 0.05). Time-series analysis revealed a significant garment × time interaction for perceived comfort (p = 0.0125), indicating divergent perceptual trajectories despite similar global means.
CONCLUSION:
In conclusion, FIR-emitting garments significantly attenuate cardiovascular and central thermal strain during moderate-intensity cycling in temperate conditions. The simultaneous reduction in heart rate and core temperature suggests that FIR technology facilitates a more efficient heat redistribution rather than affecting total metabolic heat production. Future studies should focus on the applicability of FIR in cycling at intensities higher than VT1.

References:
1. Bontemps B, Gruet M, Vercruyssen F, Louis J. Utilisation of far infrared-emitting garments for optimising performance and recovery in sport: Real potential or new fad? A systematic review. PLoS One. 2021.
2. Ferguson, J., Hadid, A., Epstein, Y., & Jensen, D. Effect of Clothing Fabric on 20-km Cycling Performance in Endurance Athletes. Frontiers in sports and active living 2022.