No matter how hard we train, we can’t outrun (or out-swim or out-cycle) aging. What we can do, however, is know what to expect as we age, so we can plan our training accordingly. In this case, we’re talking about training zones: heart rate and functional threshold power (FTP). Two of the most common ways to measure progress—and avoid overtraining—have different factors that cause these zones to decline over time, and we are here to explain why and what to expect.
Why Heart Rate Training Zones Change As We Age
Even the top athletes can expect changes in heart-rate training zones with age. While research indicates that exercising at least four days per week can not only increase oxygen intake but also improve elasticity to the left ventricle—which hardens as we age and the more sedentary we are—athletes can still expect their heart rate to go down when exercising. No matter your age, your heart rate training zones should be specific to each sport. You won’t notice much of a change in your resting heart rate with age, but it does beat slower during exercise (thanks to changes in the blood vessels and hardening of the arteries).
Of course, the heart isn’t the only factor that contributes to changes in heart rate. “Besides changes to the heart, other physiological changes that occur with age, such as sarcopenia (loss of skeletal muscle mass and strength), will affect how we perform in training and racing,” explains Joan Scrivanich, an exercise physiologist and coach at Rise Endurance.
This not only means you may want to change how you determine heart-rate training zones—Scrivanich instructs it is best to base it on heart rate at lactate threshold versus maximum heart rate—but your training will look different as you require longer warm-ups and recovery. Additionally, should you take any medication or see any changes in your blood pressure as you age, it may also affect heart rate. Because of this, Scrivanich adds that you should always communicate goals with your doctor—particularly if you’re training consistently as you may have needs that are different than the regular patient.
And of course, heart-rate zones on the bike and run are always different—regardless of age. “The heart-rate zone on a bike will tend to be lower than for a run,” shares Ben Greenfield of Ben Greenfield Fitness and author of Boundless. “[This is] because of few upper body muscles being utilized and less cardiovascular demand for blood delivery, thus a higher stroke volume due to higher venous return, and thus a lower heart rate training zone for a bike.”
Why FTP Changes As We Age
If you’re not using heart-rate training zones on the bike and instead use a power meter, it’s likely you are using FTP to guide your training (which has been found to be an extremely reliable way to train). Rob Manning, DC, owner of Tailwind Coaching, reminds us that heart rate is a measure of input and FTP is a measure of output. Like heart rate, you can expect that to change as you age, as well. This can be attributed to VO2 max, of which FTP is a percentage of.
Research once again points to physiological changes slowing our training down as we age, specifically noting that “VO2max seems to be the most important physiological factor for women as well as men.” In this case, it is powered by the lower limbs, increasing your aerobic capacity and oxygen intake.
“Other factors that cause changes in FTP are mainly related to the amount of training you execute at your FTP, near it, and above it. One of the best ways to increase your FTP is to ride just below it in an area, we call ‘sweet spot,’ which is roughly 88-93 percent of your FTP,” advises Hunter Allen, CEO and founder of Peaks Coaching Group. “As we age, the more intense work we do, the more we are able to stave off ‘aging.’”
When Athletes Can Expect Age-Related Changes
You’re probably expecting that when these changes take place varies from athlete-to-athlete and if so, you’d be correct. With both expected performance decline and physiological changes at play, Allen notes that there is no standard degradation. “[However,] each of us will experience it,” he adds.
What you can expect, however, is for your age-related changes to occur in the swim and on the run before cycling. Further, if you’re doing iron-distance racing versus Olympic-distance triathlons, expect to see greater decline at larger mileages—in both running and cycling.
Retesting FTP and Heart Rate Training Zones Is Key As We Age
Whether you are using FTP or heart-rate training zones—or both—experts agree that on average you should test every eight weeks. Manning adds that different coaches will have different testing frequencies, with four weeks being the minimum. Testing will not only help you evaluate your current fitness level, but also reset training zones. Because of this, Allen stresses you should test following a rest week, “when you are fresh and strong.”
Furthermore, if you’re consistently testing and retesting, you’ll have a better handle on zones as they drift downward as you get older, enabling your training to be more accurate—and less frustrating—as you inevitably age “into” different training zones.
Related: Don’t Let Age Slow You Down