Thank you for the article titled Missing Your Max? With so much new information/research coming out regarding maximum heart rates, it is refreshing to see PTontheNET.com address these issues. I do have a question about something that was simply noted in the last paragraph of this article. What is the difference in maximal heart rates in relation to different activities? The physiological and biomechanical differences in activities have varying affects on heart rates/maximum heart rates. I understand the physiological impacts of exercise on the unfit/beginner exercising population; however, not all of the exercising population falls into this category. Thanks again, and keep up the excellent work!
Maximum heart rate is activity specific. That means that maximum heart rate for running is different than that for cross country skiing. The factors that affect maximum heart rate are environmental, individual and muscles involved in the activity. I'll take those one at a time:
Maximum heart rate is lower at higher altitudes. Roughly, it drops one beat per 1,000 feet. If you climbed to the top of Mt Shasta in California, which is 14,000 feet, you would drop your maximum and adjust your zones down 14 beats per minute. The reason for this is that the heart is an aerobic muscle. Cardiac tissue cannot go into oxygen debt, so when partial pressure of oxygen declines, maximum heart rate declines.
The size of your heart is singularly probably the most important reason that maximum heart rate is specific to each person. Just like one guy who is 5'10" might wear a men's size 8 in shoes and another the same height may wear a size 11, so maximum heart rate is specific to each person. The larger the heart, the lower the maximum heart rate. The smaller your heart, the higher the maximum heart rate. In the animal world, an elephant's maximum heart rate is 30 bpm and a hummingbird’s is 500 bpm.
The position of your body, the number of muscles recruited and the medium you exercise in affect maximum heart rate. A good example is swimming - one is in a prone position, using the smaller muscles of the arms and back versus the torso and gluteus muscles. The swimmer is immersed in a thermally cooler environment - the temperature of water. Maximum heart rate for swimmers is typically 15 to 30 bpm lower than for runners.
I don't want to forget to mention the affect of primary sport activity on maximum heart rate. For most triathletes, running is the highest followed by about 5 to 10 bpm less for cycling and about 20 to 30 bpm lower for swimming. However, if the athletes’ primary sport is cycling, then it is not uncommon even though it is a weight-bearing sport to see their running and swimming maximums nearly identical.
I could write more about these differences, but I'd rather challenge you to find out for yourself. Go to your health club and on alternating days, take your heart rate as high as it can go following the 5 bpm every 15 seconds assessment. This is called the "biggest number test." You need to be healthy to do this assessment because it takes you near 100 percent of your maximum. After a thorough warm up, increase your heart rate 5 bpm every 15 seconds until you peak out. Wait 48 hours and try the biggest number assessment again on a different piece of equipment - try it rowing (seated) on an elliptical (killer on the legs) and then compare it with indoor cycling and treadmill. Try it on every piece of equipment, and find out for yourself your individual maximum heart rate that is equipment specific.