Muscles In Minutes

Plenty of pain, little time and a lot of effect? High Intensity Training (HIT) is said to make you stronger, fitter and give you more endurance after a few minutes of extreme exertion. At least that is the theory. The question is, what effect do full power work-outs have?

Zumba is done, high intensity training sessions are en vogue: according to a study by the American College of Sports Medicine (ACSM), High Intensity Training (HIT) is the world’s biggest fitness trend in 2014. Instead of working moderately and over time at one level, high intensity training sessions systematically push you to your limits. For example, you’ll sprint for three or four minutes at such speeds that you cannot make it one second longer. “HIT appeared on our top 20 list for the very first time in 2014. This proves how quickly this type of training has impressed fitness enthusiasts,” says Walter R. Thompson, head of the research. It is no surprise. Most people suffer from an acute lack of time; to be able to exercise for a short time at a very intense and effective level looks to hit the nail on the head.

Though this type of training is not really new. “Performance sports training has always applied interval drills to increase endurance,” explains sports physician Andreas Nieß, University Tübingen. “As early as the Thirties middle- and long-distance runners trained according to this concept.” Prominent runners like Emil Zatopek, a Czech runner also called “Locomotive”,  owe their success to ultra-tough interval training. In the last decade HIT has also gained significance for game sports where endurance is required. “Soccer players, for example, were able to improve their maximum oxygen intake with less training time involved than any continuous training”, Nieß explains.

hitHigh Intensity Training (HIT) or High-Intensity Interval Training (HIIT) is a training method applied to improve endurance. It uses the highest intensity exercises an individual will endure in intervals between 30 and 300 seconds. The restorative phase that follows is either the same or longer than each period of stimulation. The intensity of each stimulation interval is between 80 to 100 percent of the exercising individual’s maximum oxygen intake. Maximum oxygen intake is the maximum amount of oxygen the body can absorb from the air breathed in under maximum stress. During moderate endurance training (motto: run without gasping for air) the athlete exercises without a break usually at a relatively constant and low stress intensity, where the level of stimulation generally lies between 50 to 80 percent of maximum oxygen intake.

There is a plethora of studies covering the effects of high intensity training methods. Martin Gibala of  McMaster University in Ontario divided bicyclists into two groups. During two weeks one group exercised six times for two hours on a stationary bike, while the other group trained six times for ten minutes at high intensity and completely exhausted themselves. The result? Both groups increased fitness and endurance to the same level. Other analyses showed that even extremely fit athletes were able to considerably increase their endurance with HIT.

High intensity training has a positive effect even on type 2 diabetes and cardiovascular disorders. Researchers found that as little as three training units with intervals of ten minutes each can considerably lower blood sugar levels. Sports physician Nieß: “This also makes HIT interesting to people who exercise with a preventative or therapeutic goal, and who have so far subscribed to continuous training methods.”

Yet, to increase general endurance high intensity power training is not enough. “A marathon runner cannot forego endurance runs over long distances because he or she needs to prepare the muscle metabolism to cope optimally with the 42.2 kilometers of the competition,” recommends Nieß. HIT novices should start their training cautiously under professional supervision to avoid overstressing and injuries. A medical check-up prior to starting the training is recommended.

Those who overdo power training and exercise at high intensity for more than five hours per week increase their risk for heart attacks. This is the result of two independent studies sketched out by the trade publication “Heart”. Other research claims that HIT may be beneficial to increase fitness even after bypass surgery. It may even be a method to improve performance in patients with cardiac insufficiency.

It is clear that not everyone can withstand major physical stress. HIT is not recommended for beginners new to sports: “Beginners lack sufficient muscular endurance, resilience of the connective tissue, and joint stability,” Cologne-based sports researcher Ingo Froböse explains. “Training with a high intensity level is not just unsuitable for them but also dangerous.”