Age has not necessarily treated three times Olympic rowing coach Terry O'Neill well. His hair is frosted, his joints creak and he's on the same diet as his new granddaughter. However, the one benefit, apart from the fact he's allowed to wear jogging bottoms in the office, is that he has amassed an unearthly amount of knowledge about indoor rowing and training. To take advantage of this knowledge – and you're advised to so before winter, just to be on the safe side – send an email to tels-tales@therowingcompany.com. Nick Butcher: I've just started training using a HRM and am confused. It seems to my uneducated eye that your range will be lower for each training band if you are fitter. And that seems oddly counter intuitive to me!I'm 39, my resting heart rate (RHR) is 42 and maximum heart rate (MHR) is 186. So my heart rate range (HRR) is 144. Using the calculation: % HRR + RHR, my UT1 (70-%-80%) is 142.8 - 157.2. If, however, you are 39 and your RHR is - say - 65 (not as fit?) and your MHR is a standard 181 (220 - 39) then your HRR is 116 and using the same calculation your UT1 range is 146.2 - 157.8. So the less fit person has to exercise at a higher heart rate than his/her fitter compadre. And though there's not much in this example, if MHR is 181 and RHR is 80 the UT1 range will be 150.7-160.8.Other calculations give other examples of course but the constant seems to me to be that if your MHR is roughly the same, your UT1-type bands will always be higher if your RHR is higher (i.e. if you are less fit) As I say, this seems counter-intuitive to me - surely the fitter you are, the higher your comfortable, and therefore effective, range? Are my maths wrong or are my expectations simply confounded by years of 'the more it hurts the better it is for you'? Terry O'Neill: It's a good point, but only valid if heart rate is the only measure of intensity. The reason it can appear counter intuitive is that the heart responds to an increase in demand for oxygen from the working muscles. As a result of training, you increase your level of fitness, which means your muscles are more efficient. The more efficient your muscles, the greater the consumption of oxygen and therefore the higher the heart rate required to supply it. An unfit person with a low muscular efficiency will have a lower oxygen consumption and therefore a lower heart rate. Another effect of training is to increase the stroke volume of the heart, which enables the heart to pump more blood per beat. This means that the heart rate will come down for a given workload. So you can have a lower heart rate either because of a high stroke volume, which is Fit, or low muscular efficiency, which is Unfit. To measure fitness you need also to consider, pace and duration as well as heart rate. Furthermore, it is not wise to compare one person's heart rate with another but individual changes. 220-age as a guide to maximum heart rate is no basis on which to build an argument, as it is a totally arbitrary figure; you would need to find the actual heart rate max, which could be lower in an unfit person. If you look at the pace guide you will see that as you get fitter, for the same training bands, your pace and duration increases.