Resting Heart Rate - retail distribution

Get a few endurance athletes together and at some stage they'll start comparing.

'How low is yours?'

'It was 36 once.'

'Mine's 55 but I'm faster than you.'

Resting heart rate, oh if it was an indicator of performance we'd have no need to race each other! However it is an indicator of sorts. So what does it all mean?

When you're at rest your body still needs to function. Muscle, digestive system and brain need blood because they need oxygen. So your heart keeps on beating. The rate at which it beats per minute is your heart rate. This figure is affected by numerous variables such as your sleep levels, illness, training state, nutritional status and so on. It also varies from one individual to the next. So is it a pointless measure?

Not really. On an individual level it indicates the state of our cardiovascular system.

Consider a restaurant that needs to be supplied with fresh ingredients. The restaurant is the end user of oxygen, the road system the blood supply, the truck is the heart. A large truck needs to make fewer journeys. An efficient restaurant wastes less food, therefore needs fewer supply trips. A wide and fast flowing road network allows the movement of supplies to be unimpeded, meaning fewer trips required. 

With us, a large left ventricle in the heart, which increases in volume through training, means more oxygen is pumped per beat. Endurance trained cells are more efficient at unloading oxygen and endurance trained blood vessels are wider and more elastic. The net effect is that endurance training will lower your resting heart rate, but won't necessarily mean you're better than someone with a higher resting heart rate. The lowest I've seen was 31, then I panicked and it went up! Generally low 40's is common with endurance athletes, but I've known some to be in the high 50 and low 60s.

Ultimately, it's a way of tracking your improvement, but then so is the gear you use going up a certain hill :)