TRIMP turns your heart rate during a workout into a single number representing training stress — helping you balance load and recovery without guesswork.
TRIMP — Training Impulse — is a simple way to put a single number on how much a workout actually cost you: duration multiplied by intensity. Pulse Rate adds up your TRIMP across the week so you can see whether your load is too light, about right, or heading toward overreaching. This guide explains the metric and how to read it.
The variation between heartbeats — your nervous system's report card.
Two metrics, one number. Why Pulse shows both — and which to watch.
Training-impulse: your weekly training load, in one chart.
TRIMP = Duration × Average HR × Intensity Weighting. The higher your heart rate relative to max, the more stress each minute contributes to your daily score.
After a session, open Pulse Rate and record your workout duration. The app uses your heart rate zones to calculate a TRIMP score automatically.
Review your weekly TRIMP totals in the trends view. A sustainable training week typically shows gradually increasing load with planned lower-load recovery days.
When your weekly TRIMP spikes significantly, your body needs more time to adapt. Use the morning HRV reading to confirm readiness before your next hard session.
The same chart that lives on your iPhone's Progress screen — rebuilt so you know what you're looking at.
Outstanding score. Your key heart metrics are above normal.
Most healthy adults fall within this range.
Not necessarily alarming — but worth monitoring.
If this persists, please consult a healthcare professional.
TRIMP = duration × intensity. A 60-minute easy run scores about 70 TRIMP. A 30-minute interval session scores 110. Pulse adds them up daily and tells you when your week is too light, just right, or about to overcook you.
TRIMP stands for Training Impulse. It combines how long you trained with how hard your heart was working, producing one number per session so you can compare an easy hour against a short, brutal interval set.
As a general guide Pulse treats roughly 80–140 as an optimal weekly load, 140–200 as a stretch worth watching against your HRV, and 200+ as overreaching territory. Your personal sweet spot shifts with fitness.
They work together: a rising weekly TRIMP with a falling morning HRV is the classic signal that you are accumulating fatigue faster than you are recovering. Pulse charts both so you can spot it early.
No. Pulse derives training load from your logged sessions and heart data on the iPhone, so you can follow your weekly load without a watch or strap.
You've already got the hardware — your iPhone. Pulse does the rest.
Free to download · Core tracking always free · iOS 15+