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Exercise of the Month - February 2009: “Interval Training”

Attenuating the aging process is a goal many of us shoot for. Sure, people in their 20s and even 30s don’t put much thought into it, but I know many in their 40s, 50s, 60s, etc… who exercise to slow physiological aging. Interval Training (IT), when performed correctly, is a great way to increase oxygen demands and slow the aging process. Interestingly enough, IT makes your mitochondria more efficient.

Wait a second, what the heck are mitochondria? Simply put, mitochondria are units of your cells that are responsible for energy production. Adequate interval training facilitates the usage of mitochondria by improving energy production. An applicable analogy is the healing process from a cut/wound. The quicker a wound heals, the greater ability your mitochondria function. In the exercise world, the harder a person exercises, the greater the mitochondrial changes. This leads to a progressive change in biological age as time goes by.

interval training class

Incorporating IT into your workouts should initially be a manipulation to any major training variable (i.e. speed, resistance, range of motion). Specifically, implementing a system where you alternate your speed at specific time intervals during a cycling workout is a great way to begin. While I much prefer Airdyne bikes (pictured), a spinning bike or stationary bike are acceptable. A basic template would look as follows for a 3-week cycling interval workout:

Week 1 (cycling MON, WED, FRI): 15 sec. sprint; 45 seconds rest x 8
Week 2 (cycling MON, WED, FRI): 15 sec. sprint; 45 seconds rest x 9
Week 3 (cycling MON, WED, FRI): 15 sec. sprint; 45 seconds rest x 10

As you can see from the above, a work:rest ratio of 1:3 is performed with 1 additional sprint done each week. While the goal at first would be to increase the number of times you can perform the above, one thing to think about would be manipulating the work:rest ratio as time goes on. That is, you’d eventually work towards a work:rest ratio of 1:2 if possible.

While I am a huge proponent of IT, I do recommend using a heart rate monitor to get an idea where your heart rate falls during the workouts. The aforementioned cycling progression is one where only time is taken into account. The gold standard is to start and stop the intervals when your heart rate reaches a certain level. For example, each interval would begin when your heart rate reaches a certain pulse number rather than starting after a certain amount of time passes. I refer to this as “physiological intervals” rather than “timed intervals.” If a heart rate monitor is not an option, try the basic times intervals for now. In a future edition, I’ll discuss more about interval training. Between then and now, give the IT a try. E-mail me ( if you have specific questions on program design.

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