Elastic Tubing Resistance Training and Autonomic Modulation in Subjects with Chronic Obstructive Pulmonary Disease

Table 2

Intergroup differences for heart rate variability, muscle strength, and walking distance between the moments before and after training.

Descriptive	Elastic tubing; ()	Conventional training; ()
Heart rate variability
rMSSD (ms)	2,25 (9,00)	2,80 (6,40)	0,923
SDNN (ms)	2,45 (13,75)	3,20 (12,70)	0,879
LF (ms^2)	7,50 (189,50)	27,00 (138,00)	0,478
HF (ms^2)	16,50 (138,50)	23,00 (87,00)	0,989
LF/HF	−0,03 (1,55)	0,42 (1,45)	0,459
VLF (ms)	13,50 (414,50)	89,00 (276,00)	0,496
Total power (%)	193,78 (818,00)	161,00 (337,00)	0,465
TINN (ms)	2,50 (85,00)	10,00 (85,00)	0,428
RRtri	0,90 (2,87)	0,69 (3,18)	0,857
SD1 (ms)	1,65 (6,30)	2,00 (4,50)	0,945
SD2 (ms)	2,90 (19,38)	5,50 (19,10)	0,857
Muscle strength and walking distance
Knee flexion (N)	14,88 ± 28,35	16,54 ± 21,05	0,550
Knee extension (N)	11,80 ± 32,52	19,91 ± 42,99	0,510ª
Shoulder flexion (N)	4,42 ± 14,74	9,24 ± 13,38	0,292ª
Shoulder abduction (N)	6,79 ± 13,67	6,44 ± 9,60	0,929
Elbow flexion (N)	0,91 ± 44,00	7,45 ± 35,07	0,550
6MWT (m)	35,83 ± 73,27	28,89 ± 30,11	0,700

: significance level by Mann–Whitney test or “a” for Student’s -test for unpaired data; ms: milliseconds; ms²: squared milliseconds; rMSSD: the root mean square of successive difference between consecutive heart beats; SDNN: the standard deviation of normal-to-normal intervals; LF: low frequency; HF: high frequency; VLF: very low frequency; TINN: triangular interpolation of the interval between consecutive heart beats; RRtri: triangular index; SD1: standard deviation of instant variability; SD2: standard deviation of long-term interval between consecutive heart beats; 6MWT: distance walked in the six-minute walking test; N: Newton; m: meters. Values are expressed as median (interquartile range) or mean ± standard deviation.