Objective. This study aimed to compare cardiovascular and muscular acute responses of descending (DSW) and ascending (ASW) stair walking in patients with symptomatic lower extremity peripheral artery disease (PAD).
Methods. Patients randomly performed DSW and ASW exercise sessions (matched for mechanical work) consisting in 6 repetitions of two min effort interspersed with two min recovery. At the end of each repetition, heart rate (HR), systolic blood pressure (SBP), rate of perceived exertion (RPE), calf muscle oxygen saturation (StO2), and claudication pain were assessed. Plantar flexion maximal voluntary isometric contraction (MVC-iso) was measured pre-, post-, and 48h post-exercise. Delayed-onset muscle soreness (DOMS) was assessed at 24h, 48h, and 72h post-exercise. Perceived enjoyment of the training sessions were also recorded.
Results. Nine symptomatic patients with chronic Fontaine stage II PAD were included (62.0±2.4 yr; ankle-brachial index 0.77±0.05). Compared to ASW, DSW elicited a significantly lower HR (-17%, P≤0.001), SBP (-18%, P≤0.001), RPE (-30%, P≤0.001), calf muscle desaturation (-11%, P≤0.001), and claudication pain (-60%, P≤0.001). DSW was significantly more appreciated (+16%, P=0.02). Compared to post-ASW, MVC-iso was significantly lower 48h post-DSW (-8%, P=0.03). In addition, DOMS was significantly higher following DSW session (main effect over the three time points: +76%; P=0.035).
Conclusions. At matched mechanical work, DSW elicited lower cardiovascular response and calf muscle desaturation compared to ASW in symptomatic patients with chronic PAD. DSW was associated with decreased claudication pain, likely contributing to greater perceived exercise enjoyment. Introduced progressively in training programs to minimize muscle damage, DSW may be a promising and complementary training modality to optimize health-related outcomes in patients with symptomatic PAD. Further studies are however needed to determine benefit of DSW on walking impairment in chronic PAD.