Is the heart rate monitor value for money?
To train purposefully is one thing, but if it is not enjoyable during the process most people often run out of steam. Therefore you should not underestimate the importance of the heart rate monitor’s motivating factor.
But having said this, the ideal situations is that you basically know yourself and your body so well that you can make up your own mind in any situation, if you need to train harder, train with a more easy going attitude or perhaps have a rest day. If everything really comes together, the person can feel several months before the goal what kind of training is required in order to get most out of the situation.
It is exactly this ability that will only be an opportunity for the most experienced riders who have ridden for many years. The rider should also have a little “flair”, which is not an ability everyone possesses. A heart rate monitor would be helpful in everyday life for the vast majority, but you should consider what importance the above advantages and disadvantages have for you.