Recent research indicates that one solution to aging (slowing it down, that is), lies in the ability of our muscles to maximally use oxygen, both at rest and during exercise. In fact, regular aerobic exercise may decrease biological age by as many as ten years. Maybe more. (British Journal of Medicine, Dr. R. J. Shepard, 2008) The harder you exercise (read: Intense!) the greater the reduction in biological age.

I’m a huge fan of interval training, and when I read these studies promising such benefits, I just get giddy. Interval training is one of the most effective ways to achieve the level of intensity needed to increase the oxygen demands of your muscles. Maximal oxygen consumption peaks at around age 35, and as with all things, declines with age – especially so after age 60.

I’m tackling cardio interval training in this blog, but similar tactics can also be applied to strength training. It’s almost a sure bet you’ll see that post next!

Interval Training = intense exercise (all out effort) for short bursts. For the purposes of this post, and assuming you are in good health, 1-3 minutes should do the trick. This may seem overly simplified, but a good example would be your regular running workout. We call this “steady state” training – your pace is constant, your breathing is comfortably challenging, you could go all day at the same pace. Interval training shocks the system, so to speak, by elevating the heart rate to about 85% of its max. This is where the real changes that slow aging take place.

Incorporating interval training into your workout

There are many ways to skin this cat. To keep things simple, I’ve listed the most common ways interval training can be incorporated into a steady state workout:

• Increase your speed. Make certain you are injury free and in good health before you choose this method, as increasing speed has been linked to higher injury rates than other modes. (Carrol et al. 1992)
• Add impact. Squat jumps, burpees (squat thrusts), explosive jumping from the ground to a stair step or other raised platform…anything that briefly increases the intensity the exercise you’re doing. I like to incorporate plyometrics into track workouts, where running/jogging laps are briefly interrupted with a set of high-knee skips, explosive lateral shuffling, or power jacks (exagerated jumping jacks).
• Add resistance. If you’re working out on a stationary cycle or elliptical machine, this is a very simple component to change. Simply increase the resistance for short bouts. To determine if the resistance is hard enough, I use this general rule of thumb: if you have to lower resistance after 15-20 seconds, the resistance is too high. If you can continue past 3 minutes, it is likely too easy. In other words, after 1-3 mins, you WANT (or need) to end the interval and begin a 2-3 minute recovery.
• Increase the incline. This is easier to manipulate on a treadmill, however hill work can be incorporated into an outdoor workout too. If you’re on the treadmill, you can keep the speed constant, but increase the incline for short periods. Again, 1-3 minutes is sufficient. One of my favorite outdoor versions of this involves my sister-in-law’s neighborhood in Wake Forest, NC where the hills are steep and abundant. When we visit, I lace of up shoes, warm up for 5-10 minutes,  and head one block south of her home where the route around this large block starts uphill, then levels off before going down hill for the recovery part of the workout. I credit this workout with helping me tackle the hills in last spring’s Flying Pig half-marathon in Cincinnati.

Make sure the recovery portion of the interval is two to three times as long as the all-out effort. If your interval was 1 minute long, then the recovery should be 2-3 minutes. Perform your interval workout once per week for starters, increasing to two times per week (not on successive days) to see further improvements.

* Note: Blue Sky Gym and the author disclaim any liability for any injury, physical or emotional, suffered during or as a result of exercise or activities recommended. As always, you should use common sense and consult your health professional before beginning any exercise routine or program.