Effects of detraining on cardiorespiratory fitness of individuals with chronic stroke

ABSTRACT

Background

Aerobic training can improve cardiorespiratory fitness in individuals after stroke. However, the effects of short-term and long-term detraining are not well known.

Objective

To determine the effects of short-term (1-month) and long-term (6-month) detraining on cardiorespiratory fitness (VO_2peak) of individuals after stroke, who participated in aerobic training.

Methods

A cohort study was developed. Twenty adults (57 ± 11 years old) with stroke were included. After completing an outpatient aerobic training, participants were divided into gain group (VO_2peak increase >1.3 ml.kg⁻¹.min⁻¹ from before to immediately after the training) or non-gain group (VO_2peak change ≤1.3 ml.kg⁻¹.min⁻¹). Cardiorespiratory fitness (VO_2peak), obtained by the cardiopulmonary exercise test was assessed one and 6 months after the end of the training (short- and long-term detraining, respectively), or collected retrospectively from patient chart (before and after the training).

Results

There was found a significant interaction effect (time*group) for VO_2peak (F= 6.108;p < 0,001). Higher values in the VO_2peak observed in the gain group with the aerobic training (F = 25.86; p< .001) were significantly reduced with short-term detraining, reaching values similar to that observed before the training and to that of the non-gain group (F = 14.81;p= .001). Both groups had similar VO_2peak values within long-term detraining (F = 2.70;p= .12), with no significant differences from the values observed before the training and after short-term detraining (0.11 ≤ p≤ 1.00).

Conclusions

Detraining on cardiorespiratory fitness of individuals after chronic stroke occurred within only 1 month. Therefore, it is important to maintain aerobic training throughout life.

KEYWORDS:

• Stroke
• cardiorespiratory fitness
• VO_2peak
• detraining

Additional information

Funding

This work was supported in part by the following Brazilian grant agencies: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) – Finance Code #001, Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), and Pró-reitoria de Pesquisa da Universidade Federal de Minas Gerais (PRPq/UFMG);Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) [Finance Code #001];Pró-reitoria de Pesquisa da Universidade Federal de Minas Gerais (PRPq/UFMG) [04/2019];Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) [302494/2018-9];Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) [PPM-00496-17];