Table 3.

Respiratory and heart rate variability measures during intermittent exercise for Young (n = 11) and Older (n = 13) females.

	Ex1	Ex2	Ex3	Ex4
Respiratory measures
Respiratory rate (breaths/min)
Young	26.3 ± 4.7	27.8 ± 5.1	28.1 ± 5.2	29.7 ± 5.9
Older	22.5 ± 3.1	24.0 ± 3.8	24.7 ± 4.0	25.4 ± 4.6
Tidal volume (L)
Young	1.19 ± 0.16	1.13 ± 0.16	1.13 ± 0.14	1.08 ± 0.14
Older	1.33 ± 0.24	1.24 ± 0.23	1.25 ± 0.20	1.22 ± 0.19
Ventilatory rate (L/min)
Young	29.8 ± 4.1	30.1 ± 3.3	30.3 ± 3.5	30.7 ± 3.8
Older	28.8 ± 2.2	28.6 ± 2.8	29.7 ± 2.4	29.6 ± 2.4
V̇O2 (L/min)
Young	17.5 ± 3.1	17.3 ± 3.1	17.6 ± 3.2	17.6 ± 3.3
Older	16.1 ± 2.4	15.9 ± 2.8	16.6 ± 2.6	16.6 ± 2.5
Heart rate variability measures
α1
Young	0.82 ± 0.28	0.77 ± 0.25	0.83 ± 0.30	0.84 ± 0.33
Older	0.80 ± 0.18	0.78 ± 0.21	0.75 ± 0.25	0.72 ± 0.27
α2
Young	1.06 ± 0.16	1.08 ± 0.13	1.02 ± 0.13	1.00 ± 0.18
Older	1.04 ± 0.23	1.06 ± 0.24	1.02 ± 0.28	1.05 ± 0.26
LLE
Young	1.54 ± 0.18	1.58 ± 0.16	1.56 ± 0.18	1.56 ± 0.22
Older	1.56 ± 0.16	1.55 ± 0.19	1.59 ± 0.13	1.59 ± 0.16
shannEn
Young	3.31 ± 0.33	3.16 ± 0.51	3.15 ± 0.53	3.20 ± 0.52
Older	3.66 ± 0.43	3.51 ± 0.42	3.43 ± 0.55	3.40 ± 0.69
CSI
Young	2.27 ± 0.74	2.06 ± 0.58	2.16 ± 0.84	2.18 ± 0.84
Older	2.22 ± 0.77	2.10 ± 0.75	1.97 ± 0.59	1.96 ± 0.71
CVI
Young	−2.70 ± 0.20	−2.78 ± 0.30	−2.79 ± 0.29	−2.76 ± 0.27
Older	−2.50 ± 0.31	−2.59 ± 0.32	−2.62 ± 0.37	−2.64 ± 0.42

V̇O₂ = rate of oxygen consumption; Heart rate variability measures as defined in Table 1.