Abstract
Endurance training results in diverse adaptations that lead to increased
performance and health benefits. A commonly measured training response is the
analysis of oxygen uptake kinetics, representing the demand of a determined load
(speed/work) on the cardiovascular, respiratory, and metabolic systems,
providing useful information for the prescription of constant load or
interval-type aerobic exercise. There is evidence that during high-intensity
aerobic exercise some interventions prescribe brief interval times
(<1-min), which may lead to a dissociation between the load prescribed
and the oxygen uptake demanded, potentially affecting training outcomes.
Therefore, this review explored the time to achieve a close association between
the speed/work prescribed and the oxygen uptake demanded after the onset
of high-intensity aerobic exercise. The evidence assessed revealed that at least
80% of the oxygen uptake amplitude is reached when phase II of oxygen
uptake kinetics is completed (1 to 2 minutes after the onset of
exercise, depending on the training status). We propose that the minimum
work-time during high-intensity aerobic interval training sessions should be at
least 1 minute for athletes and 2 minutes for non-athletes. This
suggestion could be used by coaches, physical trainers, clinicians and sports or
health scientists for the prescription of high-intensity aerobic interval
training.
Key words
endurance training - high-intensity aerobic exercise - oxygen uptake demanded - running - cycling