trimp — Progress Tracking
Training Impulse (TRIMP) is a metric that quantifies internal training load by combining heart rate data with exercise duration. Developed by Eric Bannister in the 1970s, TRIMP assigns a weight to each heart rate zone, reflecting the physiological stress of cardiovascular effort. This allows athletes and coaches to track cumulative fatigue, monitor training intensity distribution, and balance load and recovery over time. For endurance athletes, TRIMP offers an evidence-based alternative to subjective effort ratings. On Dorsi, you can analyze your TRIMP trends across sessions and weeks, helping you make data-informed decisions about your training plan. Understanding how your TRIMP evolves alongside metrics like heart rate variability and recovery readiness can optimize your progression. The following modules break down how to interpret TRIMP values and integrate them into your daily training strategy.
Practical Playbook
Understand TRIMP and Its Role
TRIMP (Training Impulse) quantifies your training load by combining exercise duration with heart rate intensity. This single metric helps you gauge overall stress from each session, preventing overtraining and ensuring progressive overload. Learn the formula: TRIMP = minutes × (HRexercise − HRrest) / (HRmax − HRrest).
Calculate Daily TRIMP After Workouts
After each strength session, record your average heart rate (from Apple Watch or chest strap) and session duration. Compute TRIMP using the formula above. For example, a 45-minute workout at 130 bpm with resting HR 60 and max HR 180 yields TRIMP = 45 × (130−60)/(180−60) = 26.25.
Track TRIMP Trends Over Weeks
Log your daily TRIMP in a spreadsheet or training app. Plot weekly totals to identify accumulation patterns. A steady upward trend indicates adaptation, while a sudden spike may signal overreaching. Compare TRIMP with your perceived recovery to fine-tune your training loads.
Adjust Your Strength Program Using TRIMP
Use TRIMP as a guide to modulate volume and intensity. If weekly TRIMP exceeds your baseline by 20–30%, consider a deload week. Conversely, if TRIMP stays low for weeks, gradually increase sets, reps, or weight. This data-driven approach optimizes strength gains while minimizing injury risk.
Common Mistakes
- Mistake
- Using TRIMP as your sole indicator of training load without considering other metrics like heart rate variability or perceived exertion.
- Why
- TRIMP gives a quantitative load estimate, but it doesn't capture recovery status or subjective fatigue, leading to potential overtraining or underestimating stress.
- Fix
- Combine TRIMP with at least one additional metric such as HRV or RPE for a more balanced view of your training response.
- Mistake
- Applying the same TRIMP thresholds to all athletes regardless of individual fitness levels or training history.
- Why
- TRIMP zones are relative; a given TRIMP value can be easy for a well-trained athlete but excessive for a beginner, risking injury or burnout.
- Fix
- Calibrate TRIMP zones based on your personal maximum heart rate and fitness baseline, and adjust them as your conditioning improves.
- Mistake
- Misinterpreting the acute-to-chronic workload ratio (ACWR) derived from TRIMP without accounting for actual performance changes.
- Why
- ACWR can flag injury risk, but relying solely on it may lead to unnecessary reductions in training when performance is actually improving.
- Fix
- Use TRIMP-based ACWR as a guide, but cross-reference with objective performance outcomes (e.g., pace, power) before making load decisions.
- Mistake
- Ignoring recovery sessions when calculating weekly TRIMP totals, assuming only hard efforts matter for load estimation.
- Why
- Skipping recovery loads skews the chronic load downward, making the acute load appear higher than it really is and potentially missing early signs of overreaching.
- Fix
- Record all sessions, including recovery workouts and active rest, in your TRIMP calculation to maintain an accurate chronic load baseline.
How the options compare
- doc.peakwatch.co — ranks #36 for this keyword
From the Dorsi blog
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Just show up. Dorsi handles the rest.
- HRV-driven readiness — today's plan adapts to how recovered you actually are.
- Adapts every session — no decision fatigue, no second-guessing your numbers.
- Apple Watch native — log a set with your wrist, not your phone.