What each tool adds
A GPS device records where you went, how far, how fast and how high or low the road climbed. A heart rate monitor records how hard your body worked while you did it. Used alone, each tells half the story. Together they show not just that a stretch was slow, but whether it was slow because of a hill, a headwind or tiredness.
This article is general fitness information. It is not medical advice or coaching. If you have a health condition, take medication that affects your heart, or ever feel chest pain, faintness or unusual breathlessness while riding, stop and speak to a doctor.
Setting up both on one computer
Most bike computers with GPS also pair with a heart rate sensor. A sensible set-up order:
- Charge the computer fully, and check the heart rate sensor’s battery or charge.
- Pair the sensor and confirm a reading, as the article on riding with a heart rate monitor describes.
- Start the computer outside and wait for it to find a satellite signal before you roll. Starting while it is still searching can give a poor first section of the track.
- Pick a screen layout with only what you need: for example time, distance, heart rate and the next navigation prompt.
The wait for a signal is usually short in open sky and longer between tall buildings or under dense tree cover.
Using the combination to pace a long ride
The common mistake on longer rides is setting off too hard, then fading. The pairing helps with this in a few ways.
Before the start. Look at the route’s profile. If you can see a big climb near the end, you know to save something for it.
Early on. Use heart rate as a brake. If your pulse climbs quickly in the first part of the ride, you are probably going faster than you can keep up. Easing back early is usually easier than recovering later. The article on pacing effort looks at the idea in more depth, and the one about your first long ride covers preparation.
On climbs. Speed will fall naturally. Heart rate shows whether you are working at a level you can maintain. Changing to an easier gear sooner usually keeps the number steadier than pushing a hard gear.
On descents. Your pulse may fall while your speed rises. That is normal. Do not use a descent as a reason to take your eyes off the road to check data.
Reading the two together
A few patterns are worth recognising, with the caveat that many things affect the numbers.
- Heart rate high, speed low. This can mean a climb, a headwind, heat, or being tired or unwell. Slow down and give yourself a break.
- Heart rate unusually high for an easy effort. Heat, dehydration, poor sleep, illness, caffeine or stress can all raise it. If it feels wrong, shorten the ride.
- Steady speed with falling heart rate across weeks. This may reflect better fitness, but it could also be weather or route differences. Compare similar rides rather than reading too much into one.
Because the readings depend on the day, treat them as clues, not verdicts.
Planning a safe, sensible route
The GPS side also helps you ride a route you know is suitable. Check the route before you leave, make sure it stays on roads or paths you are comfortable with, and carry water, food and a way to get help. The article on route planning covers that. Do not use the data to justify riding through pain or dizziness. Aim for rides that finish with something in reserve.
Battery and backup
Recording GPS and a wireless sensor together uses more battery than either alone. Fully charge before long rides, and consider turning off features you do not use. Have a backup way to find your way home, such as a phone with the route saved, and tell someone where you are going. Batteries drain faster in cold weather, so a unit that lasted all day in summer may not in winter.
After the ride
Looking at the ride on a screen afterwards is where the pairing is most useful. You can see which section took the most effort and whether your pacing was even. Keep the notes simple: what felt easy, what felt hard, and what you would change next time.
The most useful result is a ride you enjoyed and could repeat, not a record number. Let the data support that rather than replace how you feel.