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Cardio Zone Training: Part 1 of 3—Endurance

Cardio is cardio, right? Just get that heart rate up, and you’re good to go! While that old-school training may be better than a couch-potato philosophy, it’s not enough to achieve peak fitness, and it’s certainly not a good plan for the long haul.

To make every minute of cardio work fully in your favor, you need to do more than go like hell—you need to train your heart rate zones. 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, all while minimizing your risk of injury. If you use cardio zone training properly, you will not only become more fit, you will also become faster and have more stamina.

To get you and your heart started on the road to smart zone training, we asked 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, to provide an introductory three-part cardio program that trains all of your heart rate zones to improve your cardiovascular health and overall strength.

Wicks' program is divided into three one-week installments, one for each zone:

  1. Cardio Zone Training: Part 1 of 3—Endurance: Improve muscle strength and stamina
  2. Cardio Zone Training: Part 2 of 3—Threshold: Use tempo training to increase your lactic threshold
  3. Cardio Zone Training: Part 3 of 3—Speed: Break out of the comfort zone to increase cardiovascular strength
Thirty Minutes a Day, Five Days Per Week—Or More…
Wicks' cardio zone program can be done in the gym, year round, in just 30 minutes a day, five days per week. Wicks chose the 30-minute length because most gyms cap the time limit on their cardio equipment at 30 minutes during peak hours. That said, if you have the time, the inclination, and the fitness level, feel free to increase the workout time to 45 minutes, an hour, or even more. Endurance athletes in particular should consider increasing the length of these workout sessions.

Equipment Flexibility: Choose Your Position
For each of the three weeks of cardio workouts, Wicks has assigned a particular piece of equipment for you to use. These equipment pieces are suggestions, not mandates. With the exception of the third week—sprinting—you can swap out pieces of equipment and apply the same workout to another machine. That said, be sure to mix it up. You'll get the best benefits by varying not only your target heart rate, but also your method of exercise.

Made for General Audiences
One final disclaimer: The cardio zone three-week training program is a general-audience fitness program. Heart rate zones are broken down into broad areas, with the understanding that there are other kinds of zones and ways of defining them. If your zone training is complex enough that you’re concerned with those subtleties, this program may be too general for your needs.

Getting Started: Calculate Your Rate of Perceived Exertion
In this program, you will work between 50 and 90 percent of your maximum heart rate. Your maximum heart rate is generally loosely calculated as the number 220 minus your age (for example, if you are 50 years old, your max heart rate would be 170); you can also have an evaluation by a physician to determine your max more accurately.

To measure your heart rate, you can buy a heart rate monitor and use a chart like the one at the American Heart Association to keep track of it. However, by using a monitor and chart to track your heart rate, you are relying on potentially arbitrary numbers, which are immune to changes in your fitness level.

Instead, Wicks recommends you use your Rate of Perceived Exertion (RPE). Your RPE will be how hard, on a scale of 1 to 10, you perceive yourself to be working. As you get fitter, a higher heart rate will feel easier, but if you are relying on your RPE, you will continue to push yourself up to your new, higher target range. “Basing a workout on your RPE means you’re basing it, not on arbitrary values that are given to you, but on what you are putting into it,” says Wicks. It’s a method that adapts with you.

To measure your RPE, concentrate on how much talking you could do at your current rate of exertion. Below, a handy table to guide you:

Talk Test RPE Scale Heart Rate (% Max)
The weather, politics, books; you could talk about anything, with ease. 2 - 3 40 - 50%
Breathing slightly labored; you can still talk, but you have to focus. 4 - 5 50 - 60%
Breathing challenging, but doable. Talking is more effort, and you’d just as soon not. 6 - 7 60 - 75%
Breathing hard; conversation nearly impossible. 8 - 9 75 - 90%
Can’t talk without gasping for air. You can’t sustain this level of intensity for more than a few seconds—nor should you. 10 90%
Cardio Zone Week One: Endurance Training
For this first week of the three-week program, you will train in the lowest zones—your heart rate will remain in the 50 to 65 percent range of your maximum. This is called endurance training, which improves muscle strength and trains your muscles to cope with lactic acid build-up. Endurance training helps you develop greater capillary density to oxygenate muscles, which in turn will lengthen the amount of time you can maintain exercise with less fatigue.

For the endurance portion of the program, Wicks chose the bike. There are many kinds of bikes you can use—most gyms will have spin bikes, upright bikes, and recumbent bikes. For all bikes, the two variables you can control to shape your workout are cadence and resistance. On the upright or recumbent bikes, these measures are quantifiable using the bike’s programs; on a spin bike, you will have to find ways to measure these variables for yourself. For this program you can use any type of bike you have available, because you will take all of your own measurements.

Cadence: Wicks has an axe to grind about cadence, and here it is: “No matter what, you should never cycle slower than 70 RPM, nor faster than 120 RPM. To do otherwise is to have either so much or so little resistance that you risk injury.” Don’t let the bike’s computer tell you your RPM—make taking that measurement a part of your workout. To time your cadence on the bike, put your right hand above your right leg such that your right knee lightly bumps your hand each time your leg reaches the top of your pedal stroke. Now, count the number of times your knee hits your hand in 15 seconds. Multiply that number by four and you have a true measure of your RPM. That 15-second number should never be less than 17 or more than 30.

Resistance: For this program, you add resistance to achieve a goal—so you will add just enough resistance to reach a target RPE. How much resistance that requires will depend on you, and will change over time as you get more fit—and it’s for this reason that we won’t give you an arbitrary number to plug into the bike. Use trial and error, and keep close track of your RPE to know how much is enough.

Repeat this program five days during this first week of the cardio zone program to build your endurance. On your two days off, do some light cardio (jogging, walking, hiking) to stay loose.

Phase Exercise Time RPE Description
Warm-up Spin or other bike 5 mins 3 - 4 Try to set a steady rhythm, getting your breathing going. You should have light resistance on the bike, so that you are not just spinning the pedals, but have to put light pressure against them to keep them moving.
Phase I Spin or other bike 10 mins 5 Increase your speed to bring your RPE to 5 or a little more. Use the knee test to measure your cadence; you should be at around a 24 or 25, or 90 to 100 RPM. Settle into that rhythm, and don’t drop off it for 10 minutes. This is going to feel like a very long time; Wicks advises, “To get this to go by faster, break out the iPod and the tunes.”
Phase II Spin or other bike 10 mins 6 - 6.5 To bring your heart rate just one notch higher, you will now increase your resistance. Keep the same speed as in Phase I, but increase your resistance until you perceive that you are working a little harder, and it is a degree more difficult to speak; try to stay just below an RPE of 7. Still at 90 to 100 RPM, maintain this resistance as you cycle for another 10 minutes. Again, 10 uninterrupted, unvaried minutes on the bike is going to feel like a very long time. Unfortunately, as Wicks says, “To get endurance, you have to endure.” Enduring is easier with distractions—the TV, the iPod, whatever—but don’t lose track of your speed; use the knee test periodically to check.
Cool-down Spin or other bike 5 mins 3 - 4 For this five-minute cool-down, gradually lower the resistance and your speed until you return to an RPE of 4.