Find your heart rate for every effort
The same effort gives a lower heart rate on the bike than on foot. Put in your maximum and see each effort for running and cycling side by side.
Aerobic
In and out through your nose. You could keep going for hours.
Running
121–149
65 to 80% of max
Cycling
115–141
62 to 76% of max
Threshold
In through your nose, out through your mouth. About 20 minutes, not much more.
Running
158–171
85 to 92% of max
Cycling
153–166
82 to 89% of max
VO2 max
In and out through your mouth. A few minutes.
Running
171–186
92 to 100% of max
Cycling
166–179
89 to 96% of max
Swimming has no heart-rate range. In the water your heart rate is lower again and a poor guide. Go by how long you could keep going. Learn the feel on land and take it into the water.
Find your maximum · about 20 minutes
The hill test
You need a hill, a heart-rate monitor and a fresh day. On a tired day it reads low. Press start and this page walks you through it. The highest heart rate you reach is your maximum.
Ready when you are
4:00
Next: jog easy
- Jog easy · 4:00
- Run fast · 4:00
- Climb 1 of 3, all out · 2:30
- Jog back down
- Climb 2 of 3, all out · 2:30
- Jog back down
- Climb 3 of 3, all out · 2:30
No watch?
Find the effort by feel
Your breath and how long you could keep going tell you the effort from the inside. Answer for how you feel right now, on foot or on the bike. In the water, go by how long you could hold it.
How to use the numbers
A heart-rate monitor is not there to tell you what to do. It is there to teach you what the right effort feels like. Run or ride in each range and notice your breath and how long you could keep going. When the number and the feel match, you have found the effort.
Heart rate is slow to catch up when you start working hard. On short, hard efforts, read it near the end, not at the start. And on a hot, hilly or windy day, hold the effort and let the pace drop.
Why the bike sits lower: in a lab study of 143 triathletes, at the point where easy turns into moderate, heart rate was about 10 to 13 beats lower on the bike than on the run. (Price et al. 2022) The age estimate is 208 minus 0.7 times your age. (Tanaka, Monahan and Seals 2001)
The thinking behind this is in the book: Learn to feel the right effort by heart rate.
The app holds each session at the right effort on your Apple Watch on every run and ride, and plans the next day from how this one went.