High intensity interval training refers to the basic concept of alternating brief periods of vigorous exercise with short periods of recovery. Serious endurance athletes have long appreciated its powerful performance benefits, but what is the scientific evidence to support claims that HIT will improve your health?
When describing the current state of interval training research, I often use an analogy borrowed from the pharmaceutical industry. Current physical activity guidelines, which generally call for at least 150 minutes of moderate– to vigorous-intensity aerobic physical activity per week, represent the well-established drug of choice and are based on a rich body of scientific evidence.
In its most recent “position stand” on exercise prescription, the ACSM adopted an evidence-based medicine approach, which involves the careful and systematic analysis of published literature on a given topic. It concluded that research on the health benefits associated with traditional aerobic training constituted Category A evidence, the highest rating. In contrast, HIT can be viewed as an emerging new drug on the market. It is showing considerable promise in early feasibility studies, but there is nowhere near the evidence required to suggest this type of training elicits all of the health benefits associated with traditional aerobic training.