Temperature and Blood Flow Changes in the Big Toe Skin of the Stationary Leg during Single-leg Pedaling Exercises

Abstract

[Purpose] The purpose of this study was to evaluate the changes in skin temperature and blood flow in the big toe of the contralateral inactive leg during single-leg cycling. [Participants and Methods] A single-leg pedaling exercise that used the right leg was performed by 13 healthy adult males (age 21.2 ± 0.2 years, height 172.5 ± 7.1 cm, weight 62.5 ± 6.8 kg, BMI 21.0 ± 1.6 kg/m²) in a reclined position. The exercise protocol involved four minutes of rest in a reclined position, three minutes of warm-up (load: 5 W), a period of incremental exercise (10 W/min), and a three-minute cool down (load: 0 W). Skin temperature and blood flow were continuously measured from baseline in the left big toe. The maximum work rate was measured during the period of incremental exercise. [Results] The skin temperature and skin blood flow in the contralateral inactive limb were not significantly different between rest and 10–100% exercise. Participants were divided by skin blood flow into two groups: those whose skin blood flow deviated during incremental exercise (deviance group, n=7) and those who did not show blood flow deviance (non-deviance group, n=6). Maximum exercise time and maximum work rate were significantly higher in the deviance group (max exercise time, 565.71 ± 61.73 sec; max work rate, 99.00 ± 9.96 W) than in the non-deviance group (max exercise time, 477.50 ± 59.49 sec; max work rate, 84.33 ± 9.83 W) (p<0.05). [Conclusion] The results of this study suggest that skin temperature and blood flow in the stationary leg during loaded exercises do not vary from the at-rest state. Therefore, we suggest that it is difficult to increase the skin blood flow of the big toe in the stationary leg by single-leg pedaling exercise.