Aerobic fitness testing for competitive tennis

Question: So much has been written about fitness testing in tennis, how do you evaluate if someone is fit enough to play competitive tennis, especially in the area of aerobic fitness?

Answer: The USTA Sport Science Department has been conducting tennis-specific fitness tests for well over a decade and is developing a database to truly understand what it means to be fit for tennis competition. First, there are so many areas to consider: aerobic capacity, strength, power, endurance, flexibility, agility, dynamic balance, coordination and speed, to name a few. And in such a short column it would be impossible to give you a definitive answer in all these areas. However, I will give you some general fitness guidelines concerning aerobic capacity and advise you to contact the USTA Sport Science Department for tennis-specific fitness information at the highest level of competitive tennis.

VO2 max
The ideal way to measure aerobic capacity is to be evaluated with a VO2 max test. Every time you exercise, the heart, lungs and skeletal muscles are challenged to grow stronger and improve their functional capacity. The oxygen use at which you hit your maximal effort is called the VO2 max. Exercise oxygen consumption is the best measure of metabolic rate during exercise and is determined by a VO2 max test.

A VO2 max test shows how fit you are aerobically, as well as your maximum ability to take in, transport and use oxygen. It represents the maximal health and fitness of three major body systems: your lungs, which bring oxygen in; the heart, which pumps the oxygen out to the other muscles; and the muscles that use the oxygen for energy. Those three systems are challenged every time you exercise, and that is how you become more fit. They adapt to that stress every time you exercise by growing stronger during the recovery period.

The test produces a number we can compare with other people of your same age, sex and body weight to see where you are vs. where you should be, and where you need to be going. It also can determine if you are healthy and if your heart and lungs are working well together. An exercise program can be prescribed based on the result of this test.

I recommend the VO2 Max test both before you start a training program and then every six months to see what adaptations have taken place and how fit you have become. Once you reach the advanced level of aerobic fitness, we recommend being tested once a year. Before conducting any exercise test, please get medical clearance from your family physician.

Optional test
Since VO2 max tests require the use of sophisticated equipment and technical expertise, the exam is not readily available in all locations. If you have been exercising for a while and are medically cleared for any form of exercise, another test you might try is the 1.5-mile run. The higher your level of fitness, the faster you will run a given distance. However, the intensity of a 1.5-mile run is not recommended for people who are sedentary, severely unconditioned, those with joint problems, or people who are obese. The ideal site for a 1.5-mile run is a quarter-mile track at your local high school or college. By utilizing a stopwatch and being able to measure your heart rate, you can obtain a reasonable evaluation of your cardiorespiratory fitness. Then you can look at your time, and according to your age, determine your level of cardiorespiratory fitness. I refer you to Dr. Kenneth Cooper’s book, Aerobics Program for Total Well-Being, by Bantam Books. He has detailed directions and tables to which you can refer. The times for advanced fitness levels range from 9:45 for males aged 20-29 to under 12:30 for women of the same age. As we get older, times change, so do not assume these advanced levels are for all age groups. Also, remember that these are test results for the general population; not for tennis players specifically. Again, the USTA will have much more tennis-specific data.

How to train aerobically for tennis – target heart rate
To find your target heart rate, subtract your age from 220. Next, find 70 percent of that number, and then 85 percent of that number. For example, if you’re 40 years of age, subtract 40 from 220, which gives you an estimated maximum heart rate of 180. Step two: 70 percent of 180 is 126, and 85 percent of 180 is 153. So if you’re 40 years old, your training heart rate is between 126 and 153. Also, use the method of measuring your heart rate by feeling your pulse for only six seconds, then multiply the number of beats by 10 so you get the number of beats per minute. If you measure your heart rate for six seconds while you’re active, you’d like to be between 12 and 15 beats in six seconds, which would be between 120 beats and 150 beats per minute.

Interval exercise using target heart rate
(Caution: This is intended for experienced exercisers with no medical complications.) If you have not exercised in a while, start slowly. For the first month of exercise, here’s what you might do. Warm up for five minutes. Get your heart rate into the target zone. How do you know when you’re warmed up? You’ll break a light sweat, but measure your heart rate. Practice measuring your heart rate all the time. When your heart rate is in the target zone, start walking very quickly – or maybe go up a hill, and you’ll get your heart rate up to 85 percent of maximum. When you get to 85 percent, let it come down to 70 percent, then raise it again to 85 percent and let it come back down. If you have had a very sedentary lifestyle, fluctuations between 70 percent and 85 percent will not take much effort at first. You can do this by increasing the intensity of exercise – for example, by going up a hill, or by increasing the frequency of what you’re doing. In other words, walking faster or sprint- ing if you’re a runner. If you’re not a runner, don’t try sprinting until you’re really warmed up. Remember to work your way into exercise slowly.

Once you’ve done this regularly for at least two months, you can really have some fun with interval exercise. You’ll be able to go up even outside your target heart rate range. Maybe take your heart rate up to 90 percent or you may even want to go to 95 percent. Then let your heart rate come down to even 65 percent or 60 percent. But the goal is that you peak the peak and trough the trough. By peak the peak I mean you will get your heart rate high and then trough the trough by bringing your heart rate way down. The goal is to spend about 80 percent of your exercise time oscillating in the target heart rate zone. Then you can spend 10 percent of the time above it and 10 percent of the time below it. This method helps train your body to experience intervals that simulate, somewhat, how your heart responds during a tennis match.