If you’re planning a triathlon this year in the summer, or in a different location than you are used to, please read this excerpt to plan for the adjustment your body will make. It’s an excellent excerpt from John Mora‘s Triathlon Workout Planner. This excerpt is reprinted with permission.
“Once you know your target zones, you must still do a little tweaking of the range numbers in order to further individualize your training for improved accuracy and efficiency. All training has to be individualized, and these adjustments take into account the different characteristics of each sport, outside conditions, and any illness or overtraining symptoms that may be happening within your body.
Some adjustments are sport-specific. It’s become obvious to me through the years that my heart rate while running is at least 10 beats higher than a similar perceived effort while riding my bike. That’s not uncommon, since running puts a pretty good wallop on the legs and causes a greater degree of stress on major muscle groups from the impact. Cycling is less stressful on joints, often resulting in a lower heart rate, and swimming is even less taxing.
To adjust for the unique demands of all three sports, you may want to adjust your training zones for cycling to be 10 fewer beats than what you would use for running. For example, if you’ve field-tested the target zone numbers you derived with the given formulas on a few runs at various intensities, then subtract 10 beats from your lower and upper limits in each zone to determine your cycling zones. For swimming, adjust your target zones down 5 beats from your adjusted cycling target zones.
You would also be wise to make a number of other adjustments to your heart rate training, depending on altitude, weather, and illness.
Altitude adjustments. If you are training or traveling to a race above an altitude of 6,000 feet (1,830 meters) for the first time, or if you do so infrequently, your heart rate will naturally be higher, even at rest. Above 10,000 feet (3,050 meters), you may find your heart rate is a full 50 percent higher. This increase is due to the lower concentration of oxygen in the air at higher altitudes. Of course, the more time you spend at higher altitudes, the greater your body’s ability to adapt, and you’ll probably see a return to your normal heart rate levels after 14 to 21 days. In fact, you can track your acclimatization with your heart rate monitor, noting how your rate decreases and finally gets back to normal within a few weeks. During this time of acclimatization, don’t push beyond your ability, and stay in your target zones. This means that you may have to slow down or lower the intensity of your training in the interim. Be patient—your body will adjust.
Hot-weather adjustments. Exercising in hot weather causes your body to work harder to keep itself cool. Increased blood flow to the skin and sweating cause an elevated heart rate response. The good news is that consistent training in heat brings about acclimatization in much the same way altitude training does. The body becomes much more efficient in dealing with the heat, resulting in a normal blood flow, decreased salt content in sweat, and a return to your normal heart rate. This adjustment usually takes about 10 days of consistent training or about half a dozen workouts in hot conditions. Always remember to hydrate properly (in hot or cold weather, but it’s usually more critical in heat). Dehydration can decrease your total blood volume, making the heart work harder and elevating your heart rate.
Illness. If you find that your resting heart rate has spiked unusually or that it is more difficult than normal to reach your target zones, it may well be that you are courting an illness such as a cold or flu. If you experience either or both of these conditions, back off and take a rest day or a few easy recovery workouts.”