Table 4.

Heart Rate Kinetics

	Young	Middle-Aged	Older	P-Value
HR Baseline (bpm)	78.7 ± 11.6	65.4 ± 10.4	67.5 ± 9.0	<0.001*^
HR Time Delay (s)	−16.1 ± 9.0	−10.6 ± 7.0	−11.8 ± 8.6	<0.01^*
HR τ (s)	70.8 ± 26.5	56.0 ± 22.5	83.6 ± 38.8	<0.001#
HR Amplitude (bpm)	54.8 ± 9.8	47.0 ± 7.2	41.3 ± 9.3#	<0.001*^#
HR Steady State (bpm)	131.1 ± 10.6	110.8 ± 9.5	105.6 ± 10.3	<0.001*^

Data are presented as mean ± standard deviation. bpm, beats per minute; s, seconds. The p-value represents the analysis of variance. Symbols indicate significant pairwise differences from Tukey post-hoc analysis:

^*p ≤ 0.025 for young vs. older adults

^{^}p ≤ 0.025 for young vs. middle-aged adults

^#p ≤ 0.025 for middle-aged vs. older adults.