Table 3 Main effects and interaction effects of linear mixed effects models of maximum PSI^a

Group (ref. comparison)

0.26 (0.30), t = 0.87

0.08 (0.27), t = 0.31

Max Heat Index (HI_max)^b

0.01 (0.02), t = 0.77

0.02 (0.02), t = 1.25

 medium-high

2.01 (0.33), t = 6.03

0.87 (0.43), t = 2.03

 high

2.99 (0.45), t = 6.63

1.96 (0.51), t = 3.81

 large-1

–

−0.01 (0.42), t = − 0.02

 large-2

–

− 0.73 (0.51), t = − 1.44

Age

–

− 0.03 (0.01), t = −2.95

Sex (ref. female)

–

− 0.14 (0.28), t = − 0.49

BMI

–

0.04 (0.02), t = 2.05

Group*effort

P = 0.21

P = 0.39

 medium-high

−0.61 (0.44), t = −1.40

− 0.37 (0.40), t = − 0.92

 high

−0.91 (0.57), t = − 1.60

−0.67 (0.53), t = − 1.27

HI_max^b *effort

P = 0.01

P = 0.10

 medium-high

0.11 (0.04), t = 2.71

0.08 (0.04), t = 1.91

 high

0.08 (0.05), t = 1.79

0.05 (0.04), t = 1.19