Twelve-week high-intensity interval training (HIIT), moderate-to-vigorousintensity continuous training (MICT), and Nordic walking (NW) have been shown to improve functional capacity, quality of life (QoL), and depression symptoms in patients with coronary artery disease. However, their prolonged effects or whether the improvements can be sustained remains unknown. In this study we compared the effects of 12 weeks of HIIT, MICT, and NW on functional capacity, QoL, and depression symptoms at week 26.
Patients with coronary artery disease were randomized to a 12-week HIIT, MICT, or NW program followed by a 14-week observation phase. At baseline, and at weeks 12 and 26, functional capacity was measured with a 6-minute walk test (6MWT); QoL was assessed using the HeartQoL and Short Form-36; and depression severity using the Beck Depression Inventory-II. Prolonged (between baseline and week 26) and sustained (between weeks 12 and 26) effects were assessed using linear mixed models with repeated measures.
Of 130 participants randomized, 86 (HIIT: n = 29; MICT: n = 27; NW: n = 30) completed week 26 assessments. There were significant improvements in 6MWT distance, QoL, and depression symptoms from baseline to week 26 (P < 0.05); NW increased 6MWT distance (+94.2 ± 65.4 m) more than HIIT (+59.9 ± 52.6 m; interaction effect P = 0.025) or MICT (+55.6 ± 48.5 m; interaction effect P = 0.010). Between weeks 12 and 26, 6MWT distance and physical QoL increased significantly (P < 0.05).
Twelve weeks of HIIT, MICT, and NW have positive prolonged effects on functional capacity, QoL, and depression symptoms. However, NW conferred additional benefits in increasing functional capacity. The effects of the 12-week exercise programs were sustained at week 26.