The Umeå High-Intensity Training Study

This randomized controlled trial will evaluate the effect of high-intensity training (HIT) in older sedentary people. Seventy older people, aged 65 and over, will be randomized to HIT or moderate-intensity continuous training (MICT). HIT sessions will consist of 10 repeated 6-seconds regulated high intensity cycling sprints against an individualized load. MICT (control group) sessions will consist of aerobic training regulated against an individualized load set to reach a moderate submaximal exercise intensity. Both groups will be performed twice weekly for 12 weeks. The study will evaluate the effects on 1) Cardiovascular function, 2) Brain health, 3) Muscular function, 4) Psychological health, 5) Physical activity, 6) Metabolic health, and 7) Examine the feasibility (attendance, achieved intensity, adverse events) as well as the experiences of HIT. Most outcomes will be assessed at baseline, 3 months (directly after intervention period), and 9 months by blinded assessors.