Respostas agudas da caminhada contínua e intervalada em marcadores hemodinâmicos, metabólicos e na reatividade simpatovagal de idosas

Abstract

Walking is the most popular form of physical exercise among the elderly, and its practice can delay the effects of aging. Recently, an alternative model has been proposed, known as interval walking (IW), which provides an improvement in physical fitness and health parameters. However, none analyzed its impact on hemodynamic and autonomic adjustments in the elderly, which could contribute to a better IW rescription. Objective: Measure the acute responses in a continuous walking (CW) or IW session in elderly women, and compare them according to the level of physical activity. Methods: Thirty of five elderly women, between 60 and 75 years old, composed the sample. In the first session, an incremental test was performed to determine the maximum walking speed (MWS). Subsequently, the participants were randomized to the IW (5 x 3min @ 95% MWS: 3min@ 55% MWS) or CW protocols (30 minutes at 75% of the MWS). Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), oxygen uptake (V̇ O2), glucose, blood lactate (LAC), and rating of perceived exertion (RPE) were collected in the moments before, during and after the sessions. Heart rate variability (HRV) was recorded in a supine and orthostatic position and sympathovagal reactivity was measured before and after exercise sessions. Results: In comparison to CW, IW provided greater VO2PICO (p = 0.002) and FCPICO (p = 0.004). For lactate, there was interaction, and the statistically significant increase from the pre- to the post-walk moment occurred only in IW (p = 0.003). There was an effect of the moment (pre vs. post) for SBP (F = 31.19; p <0.001), DBP (F = 6.69; p = 0.012) and glucose (F = 46.92; p <0.001 ) and RR intervals measured in the pre- and post-walk moments. Moment vs. time interaction was identified walking mode in the raiz quadrada media da diferença do intervalo de sucessivas (RMSSD, p = 0.04), and in the high frequency (HF, p = 0.04). Sympathovagal reactivity was not affected by the type of walking. Conclusions: The absence of a statistically significant difference in sympathovagal reactivity shows that, from an autonomic point of view, the two modes of walking can be safe for elderly women. Although both protocols did not differ statistically in terms of the subjective perception of effort, interval walking induced a greater metabolic and cardiorespiratory impact.