Is that a training run or a race? Training would be low to high within a zone of you got them nailed down and your plan says that.

---

-shoki

It's during training.

My issue is that for 60 to 70 minutes I'm fine and stay within range, but I then start to drift towards the lower end of the next zone. Should I be worried about that and slow down towards the end?

Nick

How do you feel ?

Increased HR in your case could be a few thing. It could be related to going to hard or dehydration

Interesting... I actually don't feel bad. But to your point I'm definitely not the king of hydration so I'll work on that and see how it goes.

hr will drift during a long run as fatigue, dehydration and perhaps temperature rise. all this is very normal.

I would not use Hr as the reason to slow down. I would trust a lot more RPE. If you feel good, keep the pace steady or finish faster in the second half and use the HR data after the workout as good feedback.

As you gain experience, you will see that Hr get affected by a lot of variable and it s not the best tool for pacing.

using pace and RPE as first metric and hr as secondary metric would be my suggestion.

---

Jonathan Caron / Professional Coach / ironman champions / age group world champions
Jonnyo Coaching
Instargram

Nailed it. HR can be helpful or confusing. Metrics can always give info. As a physician a lot of the time all you are doing is putting someone in the best situation for their body to take care of things on its own. The body is amazing. RPE will always be the ultimate tool in training and racing, but you have to focus on it in training and racing. experience is key......know thyself