What your heart rate tells you during weight training

Heart rate isn't how hard a set was. A heavy triple barely moves it while a set of 20 squats sends it through the roof. But it's still useful in the gym, if you know what to look for.

Use it to time your rest

After a hard set, your heart rate spikes and then falls. If it's still high, you're probably not ready for the next heavy set. Waiting until it settles gives you a better next set, especially on leg days.

Spot fatigue across sessions

• A higher average heart rate than usual for the same workout can mean you're tired, ill, under-slept or dehydrated.
• A heart rate that's slow to come down between sets is another sign.
• A lower average for the same work over weeks usually means you're getting fitter.

Which monitors work

• Chest straps are the most accurate for lifting, because wrist sensors struggle when you grip a bar.
• Watches and bands that can broadcast heart rate over Bluetooth work well enough for rest and session averages.
• Look for one that supports the standard Bluetooth heart rate profile, so it connects to any app.

Tip: If your heart rate is far higher than normal for a light warm-up, consider an easier session. If you also feel unwell, skip it.

Heart rate in Liftsmith

Pair any standard Bluetooth heart rate monitor and Liftsmith shows your live heart rate during the workout and on your lock screen, records it for each set and the whole session, and compares it with your usual. Session heart rate feeds the daily readiness score that decides between a push, normal or easy day.