With 5 weeks to go until the New York City Marathon, I’ve started to include some interval training in my marathon preparation. Once per week, I’m going to the track to push my heart rate to it’s maximum to attend to my VO2max. Sounds like fun, doesn’t it?
Given the popularity of VO2max and it’s importance to distance running, it’s no surprise that it has been extensively studied. Indeed, VO2max is the most often measured physiological variable in the field of exercise physiology. One of the biggest questions in the field of exercise physiology is whether VO2max is limited more by cardiac factors (which send blood and oxygen to the muscles) or by muscular factors (which use the oxygen to regenerate ATP for muscle contraction). I’ve heard many of my colleagues argue about this at scientific conferences. (Scientists like to argue.) While unfit people are equally limited by cardiac and muscular factors because they lack both a high blood flow to the muscles and abundant metabolic machinery, highly-trained distance runners seem to be more cardiac limited. Training appears to result in a shift of the limitation on the sliding scale—the more fit you become, the more you move away from a metabolic limitation to VO2max and the closer you move to an oxygen supply limitation.
While inexperienced or low-mileage runners can increase their VO2max by increasing their running mileage due to the many cellular changes that occur in the muscles, increasing the volume of slow running is ineffective for enhancing VO2max in highly-trained runners.
So, what’s the best way to improve VO2max if you’ve already been running lots of miles? Intensity. Training intensity is the most important variable to improve VO2max, with the most potent intensity being 95 to 100% VO2max. Running at or very close to your VO2max (which is the equivalent of running at your max heart rate) places maximal stress on your cardiovascular system, which presents a strong stimulus to increase your heart’s maximal stroke volume (the amount of blood your heart pumps with each beat) and consequently increase VO2max.
Imagine what your heart goes through during an interval workout. After you complete the workout, your heart says, “Geez, Jason is running hard workouts on a regular basis that cause me to reach my maximum capability to pump blood. If he keeps doing this and I don’t do something, I’m not going to be able to survive.” So, in response to the imposed threat of running at your heart’s maximum ability to pump blood, your heart responds by increasing its pumping strength and by enlarging its most important chamber so that it can send more blood and oxygen to the working skeletal muscles. Pretty elegant, huh? A larger heart increases your VO2max because it gives you a larger max stroke volume and cardiac output.
So I go to the track on Tuesdays to increase my stroke volume. Not a bad way to spend an evening.
Here’s some sample VO2max workouts for you to try:
(1) 5 to 6 x 800 meters at VO2max pace with a 1:≤1 work-to-rest ratio
(2) 4 to 5 x 1,000 meters at VO2max pace with a 1:≤1 work-to-rest ratio
(3) 3 to 4 x 1,200 meters at VO2max pace with a 1:≤1 work-to-rest ratio
(4) 15 to 20 x 400 meters at VO2max pace with a 1:<1 work-to-rest ratio
(5) 35 to 40 x 200 meters at VO2max pace with a 1:<1 work-to-rest ratio
(6) VO2max Ladder: 2 sets of 800, 1,000, and 1,200 meters at VO2max pace, with a 1:≤1 work-to-rest ratio
(7) VO2max Cut-Downs: 1 to 2 sets of 1,600, 1,200, 1,000, 800, and 400 meters at slightly slower than VO2max pace (about 5K race pace) for the 1,600, VO2max pace for the 1,200, 1,000, and 800, and slightly faster than VO2max pace for the 400, all with a 1:≤1 work-to-rest ratio
(8) VO2max Pyramid: 800, 1,000, 1,200, 1,000, and 800 meters at VO2max pace with a 1:≤1 work-to-rest ratio
Regardless of which distances you use, make the pace exactly the same (about 1.5-mile race pace for most runners; 2-mile race pace for very good runners) because the purpose of the workouts is the same: to train VO2max. Make the workouts harder by adding more reps, lengthening the distance of each work period, or shortening the recovery intervals.
I got my strong heart from my mom, who did an amazing job of raising twin boys by herself while taking care of her own mother. Here’s a bit of why I’m running the New York City Marathon in memory of her:
If you want to support my run in New York in memory of my mom, I have until October 10 to complete my fundraising. Please donate whatever you can to the American Cancer Society: http://main.acsevents.org/site/TR/DetermiNation/DNFY11EA?px=29614587&pg=personal&fr_id=54459.