Question from Ralph G.: I keep noticing that my average heart rate decreases with each day (most noticeably on the second day) when riding on several consecutive days, even though the workload is similar or sometimes even higher than on the first day. This is particularly noticeable when the routes include a lot of metres in altitude, which is unusual for me as I live near Hamburg. When I get back on my bike after a few days off training, my heart rate is immediately higher again, but then usually decreases again to a greater or lesser extent the next day and the following days. Is this normal or rather a sign of exhaustion - although I never actually feel worse than on the first day, often even better?
Answer from Dr Robert Eifler: The average heart rate is primarily dependent on the riding style, not necessarily the average speed. On inclines, for example, the pulse rate increases more than on flat stretches. Wind conditions also play a role, with headwinds requiring more power than tailwinds - which is synonymous with a higher heart rate. Intervals with corresponding breaks require strongly changing pulse rates. And in group training, the heart rate is lower overall due to slipstreaming - often despite a higher average speed.
The outside temperature also plays a role; in cold weather, the pulse rate does not increase as quickly as at high temperatures. In the case of muscular fatigue, the pulse rate does not reach its possible maximum due to the reduced performance. On the other hand, in cycling a pre-workout is practised before the day of the competition, which often involves short, intensive efforts. This activates the energy-providing systems and the cardiovascular system after the rest day, which should then enable maximum performance. In your case, it may also be a positive reaction to the previous day's exertion. The circulation then adapts with a higher stroke volume reaction of the heart, which leads to a lower pulse rate at the same performance. But overall, the pulse rate depends on so many factors (including the duration and quality of sleep) that it is not possible to give exact figures. The average heart rate is therefore not a reliable measure of training effectiveness.
