The Meaning of Fitness

 

                                                    Improvements in the Heart

 

Summary

 

 

• With exercise, the heart will increase its strength

 

• Resting pulse will drop as an indicator of fitness

 

• Maximum heart rate is dependent upon the individual, not age

 

 

 

The heart is a relatively simple pump, but unlike a mechanical pump, your heart has the ability to adapt to the rigours of exercise and improve its capacity.  Blood volume moved by the heart during intense exercise is far greater than at rest.  Therefore, if a person trains to a high level of fitness, the heart finds sedentary activity very easy.  For example, the mean average for men is somewhere between 60-70 beats per minute (BPM) at rest.  Many cyclists and runners achieve resting heart rates of 40-50 BPM and often, lower.  Miguel Indurain was famous for having a resting heart rate of 26 BPM.

 

 

The heart can be specifically adapted from an early age and this is why exercise physiologists warn against exhaustive maximal training for children.  It is better to train children for what they are not good at: endurance, or in other terms sub-maximal activity.  Many runners who turn to cycling show very low resting heart rates, as do triathletes.  However, they are often unable to compete in road races with immediate success (of course there are exceptions) because they are physically adapted to running and may well have a relatively low maximum heart rate (MHR) of around170.  If looked at closely, the average well-trained runner will have developed a very good aerobic capacity (large heart), but this will have also developed very strong muscle walls because running is a 100% weight-bearing exercise, unlike cycling, where two thirds of the body’s weight is supported.  This adaptation is mirrored in the runner’s other physical development and he or she will be relatively less supple.  This goes some way to explaining why runners find cycling and particularly pedalling, extremely difficult despite their very high levels of fitness.  With patience and training for cycling however, they often turn into the very best riders against the watch.   The implication here is that the runner turning to cycling  needs to work specifically on turning strength and power for running into the same attributes for cycling.  This can take years and lots of special training. Conversely, the “pure” cyclist turning to running will find it difficult to excel at that sport simply because the path of heart development and that of other systems, has tended not to have to cope with the rigours of a 100% weight-bearing exercise and the cyclist will have developed highly specific mobility as opposed to general mobility. 

 

In these ways, the heart can be shown to mirror the potential of the individual to some extent. It is vitally important to state that a low MHR does not mean that the individual will be useless at road racing!  Nor does it mean that change is impossible.  It does mean that the individual should assess his or her capabilities in the light of physiological realities, however.  A reasonable road-racer may be a superb time-triallist or distance track rider, for instance.  By the same token, road racers who do very well often can be heard complaining that they cannot ride a half-decent time trial, possibly because the way their body works means that anything more than a few minutes at full sustainable speed is very uncomfortable. As we have seen with riders like Ivan Basso, a relative weakness (e.g against the watch in time trials) can be improved dramatically. 

 

With the end of training through illness, boredom or the ravages of old age, the heart behaves like any other muscle and atrophies to some extent, although it will never return to its condition and size before a sedentary individual began training.  Therefore a relatively low heart rate will remain to some degree.

 

Finally, the heart is a good barometer of all sorts of physical training conditions being experienced by the body.  Therefore, consider the sense in recording your pulse at rest first thing on a morning and watching it for early signs of over-training or even illness, especially viral infections that may not show any other physical symptoms apart from a general “off” feeling.  In competition however, only use a heart rate monitor to generally assess your progress in preparation or during an event to make sure you are working hard enough or not at a suicidal rate in a medium-distance time trial.  A useful measure in a road race would be to set your HRM to upper Zone 5 and near the end of the race, confirm how you feel by checking how much upper Zone 5 or 6  you have done.  If you have done much over an hour, you basically have not got much left, but you will probably have realised this!

 

 

Tony Hodgson

British Cycling Club Coach

4 March 1996 (Revised November 2005)