Table 2.

Individual characteristics of low-, medium-, and high responders for resting T_re, ΔT_re, WBSR and HR [mean ± SD or median (Q1, Q3)] with p values from analysis of variance

	Resting Tre responders				ΔTre responders
	Low	Medium	High	p	Low	Medium	High	p
Pre- to post-HA change§ (°C)	0.2 (0.0, 0.3)m,h	− 0.1 (− 0.2, − 0.1)l,h	− 0.5 (− 0.6, − 0.4)l,m	< 0.001np	0.3 (0.2, 0.4)m,h	0.0 (0.0, 0.0)l,h	− 0.2 (− 0.3, − 0.2)l,m	< 0.001np
Sex (no. male/female)	3/5	7/1	5/3	–	5/3	6/2	4/4	–
Age (y)	27 (24, 35)	32 (30, 36)	28 (26, 36)	0.6np	34 ± 7	27 ± 5	32 ± 10	0.2
Body mass (kg)	70.7 ± 7.2	78.7 ± 12.4	77.5 ± 10.8	0.3	77.3 ± 11.9	76.7 ± 7.9	72.8 ± 12.1	0.7
BSA (m2)	1.9 ± 0.1	2.0 ± 0.2	2.0 ± 0.2	0.3	2.0 ± 0.2	2.0 ± 0.1	1.9 ± 0.2	0.7
BSA-to-mass ratio (cm2 kg−1)	268 ± 13	258 ± 18	259 ± 18	0.4	256 ± 18	262 ± 11	268 ± 19	0.4
Body fat (%)	25 ± 7	18 ± 4	19 ± 4	0.04	19 ± 5	18 ± 5	24 ± 7	0.06
$\dot{V}$O2peak,kg (mL kg−1  min−1)	46.3 ± 9.6	56.6 ± 6.1	52.7 ± 8.0	0.052	52.7 ± 7.0	56.2 ± 7.3	46.7 ± 10.0	0.09
Weekly exercise time× (min)	292 ± 117	385 ± 54	340 ± 166	0.4	406 ± 131	335 ± 115	275 ± 89	0.1

	WBSR responders				HR responders
	Low	Medium	High	p	Low	Medium	High	p
Pre- to post-HA change§ (g h−1/bpm)	70 (23, 84)m,h	250 (214, 279)l,h	455 (387, 652)l,m	< 0.001np	− 4 (− 4, − 1)m,h	− 9 (− 10, − 7)l,h	− 17 (− 19, − 15)l,m	< 0.001np
Sex (no. male/female)	3/5	5/3	7/1	–	7/1	3/5	5/3	–
Age (y)	30 ± 7	30 ± 8	34 ± 9	0.4	31 ± 8	32 ± 8	31 ± 8	0.9
Body mass (kg)	67.5 ± 7.3h	76.3 ± 9.3	83.0 ± 9.3l	0.006	83.4 ± 9.4h	74.2 ± 10.5	69.2 ± 6.8l	0.02
BSA (m2)	1.8 ± 0.1h	2.0 ± 0.2	2.1 ± 0.1l	0.02	2.1 ± 0.2h	1.9 ± 0.2	1.9 ± 0.1l	0.02
BSA-to-mass ratio (cm2 kg−1)	274 ± 15h	263 ± 12	249 ± 12l	0.005	252 ± 11	264 ± 19	270 ± 13	0.06
Body fat (%)	23 ± 6	19 ± 6	19 ± 4	0.3	18 ± 3	23 ± 7	20 ± 6	0.2
$\dot{V}$O2peak,kg (mL kg−1 min−1)	49.9 ± 8.8	55.7 ± 9.5	50.0 ± 7.9	0.3	54.2 ± 6.4	48.2 ± 8.4	53.2 ± 11.0	0.4
Weekly exercise time× (min)	303 ± 95	332 ± 107	385 ± 154	0.4	375 ± 64	353 ± 163	290 ± 118	0.4

p values ≤ 0.050 are highlighted in bold

SD standard deviation, Q1 first quartile, Q3 third quartile, BSA body surface area, $\dot{V}$˙O_2peak,kg maximum oxygen uptake relative to body mass, T_re rectal temperature, ΔT_re exercise-induced rise in rectal temperature, HR heart rate, WBSR whole-body sweat rate

^npFrom non-parametric test

^lSignificantly different from low responders (p ≤ 0.050)

^mSignificantly different from medium responders (p ≤ 0.050)

^hSignificantly different from high responders (p ≤ 0.050)

^§Pre- to post-HA change was calculated as heat stress test 2 minus heat stress test 1

^×swimming exercise excluded, n = 23