Intensity vs. Time
Hot off the presses: another study confirming the benefits of high-intensity cardio vs. traditional, low-moderate intensity aerobics…
The usual excuse of “lack of time” for not doing enough exercise is blown away by new research published in The Journal of Physiology.
The study, from scientists at Canada’s McMaster University, adds to the growing evidence for the benefits of short term high-intensity interval training (HIT) as a time-efficient but safe alternative to traditional types of moderate long term exercise. Astonishingly, it is possible to get more by doing less!
“We have shown that interval training does not have to be ‘all out’ in order to be effective,” says Professor Martin Gibala. “Doing 10 one-minute sprints on a standard stationary bike with about one minute of rest in between, three times a week, works as well in improving muscle as many hours of conventional long-term biking less strenuously.”
…To achieve the study’s equivalent results by endurance training you’d need to complete over 10 hours of continuous moderate bicycling exercise over a two-week period.
I’ve been a fan of interval training for a long time. I won’t lie: it can be grueling. But it’s also mercifully short, and – more importantly – the alternating pace makes the time seem to fly by. Whatever else it may be, it ISN”T boring.
Less time, same benefits: works for me!
March 13, 2010
Intensity vs. Time – http://blog.ultimatefatburner.com/2010/0…
March 14, 2010
Curious question….and I suspect there may be something wrong with my logic here.
I have heard that much of the gains from HIIT as opposed to moderate intensity is that is the difference in the composition of the calories burned, the former burning more fat while the latter burns more carbs. If, however, the body is already in ketosis and there are so few carbs left to burn, will it have no choice but to burn the fat instead during the workout thereby negating any real difference in this regard as far as the two types of workouts go?
March 15, 2010
As exercise intensity increases, the ratio of substrates used for energy production changes as well: carbohydrate (glucose) utilization goes up and fat oxidation drops. At very high intensities, virtually no fat is burned to fuel the work being done.
I don’t imagine that being in ketosis would change that. But your muscles can utilize some of the ketones already produced, plus glucose produced from amino acids via gluconeogenesis. In fact, this is one of the benefits postulated by higher protein/low carb diets: there’s plenty of extra amino acids that can be broken down and utilized for energy (http://jn.nutrition.org/cgi/content/full/136/1/319S )
Nonetheless, I’d think doing HIIT during ketosis would be a damned unpleasant experience, as fatigue would set in pretty quickly… neither of the above substrates is ideal for high-intensity exercise. I’m reminded of a remark made by Lyle McDonald in “The Ultimate Diet 2.0″…
“I should mention right now that high reps and short rest periods on low-carbs is a miserable, miserable experience. Nausea, lightheadedness and a general desire to track me down and kick my ass are common reactions.”
Personally, I’d think I’d pass on the HIIT if I was on a keto diet. 😉
March 15, 2010
I’m glad to see that it’s not just me being a wuss. Thanks for the info Elissa!