What is TRIMP and How to Use It?

TRIMP (Training Impulse) is a metric that quantifies training load. It's been used for decades to measure cardiovascular stress. But is it enough?

This article explains what TRIMP is, how it works, its limitations, and how OpenAthlete's algorithm goes beyond TRIMP to provide a more comprehensive training load assessment.

What is TRIMP?

TRIMP (Training Impulse) was developed by Dr. Eric Bannister in the 1970s. It calculates training load using:

• Exercise duration (minutes)
• Average heart rate
• Heart rate reserve (difference between max and resting HR)

Formula: TRIMP = Duration × Average HR × Heart Rate Reserve Factor

The result is a single number representing cardiovascular training stress.

TRIMP's Strengths

TRIMP is valuable because it:

• Quantifies training load objectively
• Accounts for individual heart rate zones
• Provides a single metric for comparison
• Has decades of research validation

TRIMP's Limitations

However, TRIMP has significant limitations:

• Cardiovascular only: Doesn't account for muscular stress
• No RPE: Ignores internal load (how you felt)
• No environmental factors: Doesn't consider heat, altitude, etc.
• No recovery status: Same TRIMP feels different when fatigued vs fresh
• No injury risk: Doesn't detect load spikes that cause injuries

Beyond TRIMP: OpenAthlete's Approach

OpenAthlete's algorithm incorporates TRIMP but goes further:

• TRIMP (cardiovascular load)
• RPE (internal load)
• ACWR (load progression)
• Recovery markers (sleep, stress)
• Environmental factors
• Injury risk detection

This comprehensive approach provides a more accurate picture of training stress and adaptation.

The Bottom Line

TRIMP is a useful metric, but it's incomplete. OpenAthlete uses TRIMP as one component of a comprehensive training load analysis that includes RPE, ACWR, recovery, and injury prevention.

Stop guessing, start training with AI today. Sign up for OpenAthlete and get training load analysis that goes beyond TRIMP.