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Cardio Zone Training: Part 3 of 3—Speed

By L.K. Regan

This article is part three of's three-part series on cardio zone training from Devin Wicks (ACSM-HFI, USAW Club Coach), a fitness operations director at the University of California, Berkeley, and specialty strength coach for some of the University's premier sports teams. Zone training, in which you target and then sustain particular ranges of an elevated heart rate, is the key to gaining the full range of benefits—muscular, cardiovascular, and metabolic—from cardiovascular exercise. You can use cardio zone training to become more fit and faster, and to develop more stamina.

If you haven't yet done so, please begin with the first two parts of this series:

  1. Cardio Zone Training: Part 1 of 3—Endurance: Get a background on the program, learn how to use your rate of perceived exertion to calculate your heart rate, and get your endurance-training program.
  2. Cardio Zone Training: Part 2 of 3—Threshold: Learn about and get your threshold training program, in which you will try to move the point of exertion at which your body begins to use anaerobic respiration.
Speed Zone Training
In previous weeks you've worked on building endurance and increasing your lactic threshold; now it's time to train in the very highest cardiac zone, sprints, in which you'll train for short bursts above 85 percent of your maximum heart rate.

Clearly, there are risks to training at this level. Your maximum heart rate is a true maximum—no matter what you do, your heart won’t beat faster than its maximum. It can’t. If you truly hit your maximum heart rate, you run the risk of exerting yourself so much that your heart cannot meet your body’s demand for oxygen, even beating as fast as it can. So while you want to approach your maximum heart rate, you don’t want to actually reach it. You also don’t want you to sustain this high heart rate for very long.

Important note: Always consult your doctor before beginning any new exercise program to make sure you are healthy enough to attempt it. This holds especially for sprints, which put a lot of stress on your heart.

Given the above warning, you may wonder, why do this at all? Sprints train your body’s efficiency at obtaining and delivering fuel, allowing you to function at high levels of exertion for longer with fewer repercussions. Through sprints, you can:
  1. increase your cardiac output (the amount of blood pumped with each beat of your heart);
  2. build up the amount of oxygen delivered to cells with each heart beat;
  3. boost your tolerance for lactic acid;
  4. enhance your glucose and fat-burning systems; and
  5. improve your ability to focus and persevere through very intense exercise.
“This is all about how strong your heart gets," says Wicks. "The more blood your heart pumps with each beat, the less hard it has to work to sustain a given level of cardiac exercise.” If you want to be able to go harder and longer, sprints will help get you there.

Notes on the Speed Training Program

Before you get started, it's important to clear up a nearly universal misconception—that sprinting is the same as full-out speed. “Sprinting,” says Wicks, “does not necessarily mean going fast. It means going at high intensity.”

Many people doing this program will be tempted to drop the machine’s resistance to next to nothing and go as fast as they possibly can. What's the problem with that? A very high risk of injury. You are almost certain to have poor form at extreme speeds. Instead, as with the endurance and threshold phases of the program, you should create the desired intensity through a mixture of variables, combining both speed and resistance with the goal of raising your heart rate, not just your miles per hour. Resistance with speed, please!

One final note: This is not reaction-time training, another context in which athletes may train with sprints. These sprints are part of a fitness training program, aimed at a more general audience.

For speed training, Wicks's program utilizes the elliptical machine—but if you want to trade to a different kind of machine you can, provided you remember to mix speed increases with another variable, either incline or resistance as applicable (either of these variables may apply to the elliptical, depending on the machine).

The speed portion of this training program is designed to be done three days per week—and no more than that! Those days off are crucial, since it is absolutely essential with sprints that you give yourself adequate recovery. “This intense workout is all about recovery. You do a lot of muscle breakdown when you sprint. And it’s during the recovery period that the rebuilding of those muscles takes place.” After you sprint, your muscles ideally recover to a new, higher level of strength; but if you don’t let them recover, they don’t have the opportunity to rebuild to that new level, and you’ve wasted all the hard work you put in. So instead of thinking of recovery as time off, think of it as the time when you actually get to collect the gains you’ve earned.

So what to do on the off days? Little to no cardio, and no heavy lifting. If you must hit the gym, Wicks recommends some circuit training-style lifting, in which you use lighter weights and lower intensity to give your body the critical recovery time it needs.

As in the endurance and threshold phases of the program, for speed training you will use your Rate of Perceived Exertion (RPE) as a measure of intensity and heart rate. To learn about calculating your RPE, see Cardio Zone Training: Part 1 of 3—Endurance".

Phase Exercise Time RPE Description
Warm-up Elliptical 5 mins 2 - 3 Just get moving. Get your breathing going and loosen up your muscles.
Speed Training Zone Elliptical 20 mins 9+ for the sprint; 3 - 4 for the recovery For the 20-minute speed training, you'll divide this 20 minutes into 30-second sprints at 9+ RPE, followed by two minutes of recovery at 3 - 4 RPE. At the end of the two-minute recovery, immediately ramp up and start your next 30-second sprint. In 20 minutes, you'll do eight intervals:

0 - 0:30 mins: Sprint at 9+ RPE
0:30 mins - 2:30 mins: Recovery at 3 - 4 RPE
2:30 - 3:00 mins: Sprint at 9+ RPE
3:00 mins - 5:00 mins: Recovery at 3 - 4 RPE
5:00 - 5:30 mins: Sprint at 9+ RPE
5:30 mins - 7:30 mins: Recovery at 3 - 4 RPE
7:30 - 8:00 mins: Sprint at 9+ RPE
8:00 mins - 10:00 mins: Recovery at 3 - 4 RPE
10:00 - 10:30 mins: Sprint at 9+ RPE
10:30 mins - 12:30 mins: Recovery at 3 - 4 RPE
12:30 - 13:00 mins: Sprint at 9+ RPE
13:00 mins - 15:00 mins: Recovery at 3 - 4 RPE
15:00 - 15:30 mins: Sprint at 9+ RPE
15:30 mins - 17:30 mins: Recovery at 3 - 4 RPE
17:30 - 18:00 mins: Sprint at 9+ RPE
18:00 mins - 20:00 mins: Recovery at 3 - 4 RPE

Make sure you sprint for the full 30 seconds; as Wicks says, “Don’t sandbag it.” You are trying to get your heart rate up around 90 percent of its max, so you should be breathing really hard, through your mouth, and should feel that talking, while possible if you absolutely had to, would require a struggle—you’d only be able to get out a few words without needing to pause, and you’d just as soon not talk at all. Likewise, you want to come all the way back on the recovery, to the point where, though you are breathing harder than normal, you can talk fluidly, in complete sentences, on any topic.
Cool-down Elliptical 5 mins 3 Use this as a recovery period again, maintaining light work as you allow your breathing to come a little slower and your muscles to recover.