Aerobic Threshold Evaluation Using a Sweat Lactate Sensor in Healthy Women

Abstract The use of a sweat lactate sensor to evaluate the aerobic threshold has not been fully validated in women with low sweat rates. This study aimed to validate aerobic threshold assessment using a sweat lactate sensor in healthy women. Sixteen healthy women who underwent exercise tests using respiratory gas analysis were included. Sweat lactate levels were monitored using a wearable lactate sensor, and the sweat rate was measured using a ventilated capsule perspiration meter. A correlation analysis between the sweat lactate threshold and the ventilatory threshold was performed. The degree of discrepancy between the sweat lactate threshold and the ventilatory threshold was also examined based on sweating dynamics. In all cases, the sweat lactate threshold was detected using a sweat lactate sensor. Although a significant correlation was observed between the sweat lactate threshold and the ventilatory threshold (r s=0.769), the sweat lactate threshold was significantly delayed compared with the ventilatory threshold, and the difference in the degree of discrepancy between the sweat lactate threshold and the ventilatory threshold increased with increasing thresholds. The onset of sweating was a significant predictor of the discrepancy between the sweat lactate threshold and the ventilatory threshold (r=0.873). Thus, in healthy women, the aerobic threshold assessment using the sweat lactate sensor was feasible. This study demonstrated that late-onset sweating was an important factor in delayed sweat lactate threshold relative to the ventilatory threshold.