Dr Allen Lim over at Saris (owner of the CycleOps brand of Bicycle Trainers) has written an interesting article on the roles of measuring power and heart rate in bicycle training.
Dr Lim highlights a shift in cycling training which means that many people have stopped using their heart rate to measure their performance while training due to the increased number of power measurement devices built into bikes and trainers. While power output is an effective way of measuring the intensity of a bicycle training session it doesn’t actually measure how your body reacts to the training.
In the article he analyses the fundamental relationship between “dose” and “response” in cycling training. In the case of heart rate and power output, “dose” is the intensity of the training (power output) and the “response” is how your body reacts (heart rate). Therefore the two are measuring different things and should be used to complement each other and not replace one another.
This means that when cycling you could have an identical power output (“dose”) but completely different heart rates (“response”) when training at different fitness levels.
He finally highlights the fact that power output and heart rate are simply two of the many tools to measure both “dose” and “response” in cycling training and that in an ideal world we would be able to measure everything to be able to coordinate our training regimes perfectly.
In the real world, for most of us, measuring heart rate and power output are about as much as we can hope for. 🙂