High-intensity interval training: cumulative fatigue and implications in prescription for physical reconditioning

Moderate-intensity physical exercise is generally recommended in cases of significant deconditioning caused by lack of physical activity or state of health, but with quite variable success.

High intensity interval training (HIIT) and, more particularly, sprint interval training (SIT) has been shown to be a very effective method of rapidly improving fitness. However, there is still work to do when talking about its optimal and safe prescription. A better understanding of its possible negative effects is required in order to specify the optimal doses for each concrete case. For instance, a big amount of cumulative fatigue could lead to a plateau on the expected benefits or even to deleterious effects on the general health condition.

This project aims to characterize how fatigue accumulates as a function of the duration, frequency and duration of exposure to this type of stimulation and its consequences on the dose-effect relationship. The cumulative fatigue will be quantified from the recovery of the high-intensity interval sessions which will be evaluated from the measurement of neuromuscular performance, the reactivation of the parasympathetic system (heart rate variability) and by perceptual-fatigue questionnaires.

The major goal is to establish how to adapt the workloads (dose, frequency, duration) and to propose monitoring methods to readjust and personalize the workloads during a reconditioning program based on high intensity interval training.