7000 PT CONSOLE
150, external factors no longer influence heart rate, and a linear relationship ex- ists. As the heart rate rises above 150, the heart
The third assumption involves maximal heart rate. Maximal heart rate is the greatest heart rate that can be measured when an individual is exercising to the point of volitional fatigue (i.e., exhaustion) during a graded exercise test. Sev- eral equations have been developed to estimate the average maximal heart rate for humans:
•Maximal heart rate = 220 minus age (low estimate)
• | Maximal heart rate | = | 210 minus [0.5 x age] (high estimate) |
• | Maximal heart rate | = | 226 minus age (estimate for older |
| individuals) |
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|
Maximal heart rate can, however, vary greatly among different individuals of the same age. One standard deviation is + 12 bpm, which means that
The final assumption addresses the issue of mechanical efficiency. Be- cause oxygen uptake at any given work rate can vary by approximately 15% be- tween different individuals, individuals vary in the amount of oxygen they require to perform a certain exercise workload. Some individuals are more
efficient at performing a given task than others. As a result, the average oxygen consumption associated with a given workload may vary significantly from one person to another. Thus, VO2 max predicted by submaximal exercise tests tends to be overestimated for those who are mechanically efficient and underes- timated for those who are inefficient.
The point to remember is that submaximal exercise testing, though not as precise as maximal exercise testing, is not without advantages. For example, the results of such testing can provide a fairly accurate reflection of an individual’s fitness status without the cost, risk, effort (on the part of the subject) and time involved in max testing. If an individual is given repeated
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