Interval Training and Time

People frequently complain about time, or, more specifically, lack of time. People don’t have time to exercise, or eat right, or take care of themselves. They don’t have time to do something every day for an hour. Cher said, “Fitness- if it came in a bottle, everyone would be thin.” We are constantly looking for a way to do things quickly, to reduce the amount of time it takes to be fit. Fortunately, research has good news for all of the people who don’t have time. Interval training in short bursts has a positive impact on cardiovascular health and metabolism. Research by Walter, Smith, Kendall, Stout, and Cramer (2010) found high intensity interval training led to a decrease in body mass and an increase in VO2 max in untrained women. Subjects performed 15 minutes of exercise on a cycle ergometer broken up into 5 sets of 2 minutes high intensity followed by one minute of passive recovery for two months. Another study, performed by Gibala, Little, van Essen, Wilkin, Burgomaster, Safdar, Raha, and Tamopolsky (2006), compared the effects of traditional endurance training to sprint interval training in college-aged men. The endurance training group cycled continuously for 90-120 minutes at 65% of their heart rate maximum while the sprint-interval training group performed 4-6 30 second sprints followed by a 4 minute recovery. After two weeks, the endurance training group had spent 10.5 hours exercising while the sprint-interval group had spent 2.5 hours exercising. The skeletal muscle and physiological changes between the groups were almost exactly the same.  

So, why is any of this important? If you are short on time and don’t feel like you have an hour to devote to exercise, you can get the same cardiovascular effects from short bouts of high intensity work. The caveat, of course, is you have to be willing to work really hard during the work interval to gain maximum health benefits. Fifteen minutes devoted to exercise can make a huge difference in your overall health and well-being. Time and motivation are a challenge for all of us. I would argue everyone has fifteen minutes a day to devote to fitness. Remember: you only have one body. You might as well use it.

Yours in health and wellness,


Walter, A.A., Smith, A.E., Kendall, K.L., Stout, J.R., & Cramer, J.T., (2010).  Six weeks of high-intensity interval training with and without beta-alanine supplementation for improving cardiovascular fitness in women.  Journal of Strength and Conditioning Research, 24(5), pp. 1199-1207.

Gibala, M.J., Little, J.P., van Essen, M., Wilkin, G.P., Burgomaster, K.A., Safdar, A., Raha, S., & Tarnopolsky, M.A., (2006).  Short-term sprint interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance.  Journal of Physiology, 575(3), pp. 901-911.