 
Supplementary Online Material 
 
Anaerobic Threshold Using Sweat Lactate Sensor under Hypoxia 
Hiroki Okawara, Yuji Iwasawa, Tomonori Sawada, Kazuhisa Sugai, Kyohei Daigo, Yuta Seki, Genki Ichihara, Daisuke Nakashima, Motoaki Sano, Masaya Nakamura, Kazuki 
Sato, Keiichi Fukuda, Yoshinori Katsumata 
 
This supplementary material has been provided by the authors to give readers additional information about their work. 
 
 
APPENDIX 
 
Supplementary Figure 1. Imaging of sweat lactate levels, local sweat rate, and blood lactate values during incremental exercise under normoxia 
Representative graphs of sweat lactate levels (orange), local sweat rate (blue), and blood lactate values (red) during hypoxic exercise with a stepwise incremental protocol (25 
W/min) ergometer are shown. 
Abbreviations: VT=ventilatory threshold; sLT=sweat lactate threshold. 
 
 
 
Supplementary Figure 2. Measured parameters in normoxia.  
The graph shows the measured parameters (a; VO2/Body weight, b; Heart rate, c; Sweat lactate, d; sweat rate) at rest, warm up, VT, and peak in hypoxia. Data are shown as 
mean (±standard deviation). 
Abbreviations: VO2=oxygen uptake: VT=ventilatory threshold: HR=heart rate: sLA=sweat lactate: SR=sweat rate. 
 
a) VO2
c) sLA
d) SR
b) HR 
Supplementary Figure 2
 
Supplementary Figure 3. Reliability testing of the time at sLT determined by the same evaluator in normoxia. 
(a) The graph shows the relationship between the repeatedly determined sweat lactate threshold (sLT) by the same evaluator (b) The graph shows the Bland–Altman plots, 
which indicate the respective differences between the repeatedly determined sLT by the same evaluator (y-axis) for each individual against the mean of the time at the 
repeatedly determined sLT (x-axis) in normoxia. R, correlation coefficient; p, p-value; ventilatory threshold; sLT, sweat lactate threshold. 
 
Supplementary Figure 3
a)
b)
R = 0.70
p < 0.01
 
 
Supplementary Figure 4. Validity testing of the time at VT and sLT in normoxia 
(a) The graph shows the relationship between the time from the start of the measurement (seconds) at VT and sLT. (b) The graph shows the Bland–Altman plots, which 
indicate the respective differences between the time from the start of measurement (s) at the VT and sLT (y-axis) for each individual against the mean of the time at the VT 
and sLT (x-axis) in hypoxia. R, correlation coefficient; VT, ventilatory threshold; sLT, sweat lactate threshold. 
 
 
pp
y
g
a)
b)
R = 0.69
p < 0.01
Supplementary Table 1. Intra-evaluator reliability of sweat lactate threshold determination in normoxia 
Hypoxia 
 
N 
Evaluator  1 
Evaluator  2 
Evaluator  3 
ICC (95%CI) 
sLT [sec] 
Mean 
20 
553.3 
486.3 
533.6 
0.782 (0.607 - 0.898) 
SD 
84.4 
89.8 
80.8 
bLT [sec] 
Mean 
20 
643.9 
605.6 
611.3 
0.621 (0.363 - 0.813) 
SD 
77.1 
67.4 
81.9 
VT [sec] 
Mean 
20 
563.1 
552.2 
552.6 
0.711 (0.500 - 0.861) 
SD 
56.5 
45.3 
60.0 
ICC, intraclass correlation; sLT, sweat lactate threshold; bLT, blood lactate threshold; VT, ventilatory threshold; 
SD, standard deviation. 
 

Anaerobic threshold using sweat lactate sensor under hypoxia.
Okawara, Hiroki,Iwasawa, Yuji,Sawada, Tomonori,Sugai, Kazuhisa,Daigo, Kyohei,Seki, Yuta,Ichihara, Genki,Nakashima, Daisuke,Sano, Motoaki,Nakamura, Masaya,Sato, Kazuki,Fukuda, Keiichi,Katsumata, Yoshinori