What is TRIMP? How Sports Teams Use It to Optimize Training

TRIMP (Training Impulse) is a powerful metric that helps sports teams quantify training load using heart rate data, enabling coaches to optimize performance, manage injury risk, and ensure athletes are game-ready. In this article, we’ll explain what TRIMP is, how it’s calculated, and how it can be applied to coaching decisions. 

Understanding TRIMP: A Key Training Load Metric 

Training Impulse (TRIMP) is a widely used method for quantifying training load in athletes. Originally developed by Dr. Eric Banister in 1991, TRIMP integrates exercise duration and intensity to provide a single numerical value that represents the physiological stress of a workout. Over the years, various modifications have been introduced to enhance its accuracy, including Firstbeat Sports’ advanced heart rate analysis. 

Unlike subjective measures like Rate of Perceived Exertion (RPE), TRIMP is an objective metric derived from heart rate data, making it a reliable tool for monitoring athlete workload and optimizing training programs. 

How TRIMP is Calculated

TRIMP is calculated by taking into account: 

• Duration of the workout (longer sessions result in a higher TRIMP score) 

• Exercise intensity (measured through heart rate relative to an athlete’s maximum heart rate) 

• Intensity weighting (higher intensity sessions contribute exponentially more to the TRIMP score) 

In the Firstbeat Sports system, TRIMP is updated in real time using beat-to-beat heart rate data, providing greater precision, particularly for interval-based training sessions.

How TRIMP is calculated in Firsbeat Sports

TRIMP in Action: How It Benefits Sports Teams

1. Monitoring Training Load in Real Time

Firstbeat Sports provides real-time TRIMP/min data, allowing coaches to assess an athlete’s workload dynamically. By tracking how TRIMP accumulates within a session, coaches can adjust training drills to ensure the desired physiological impact is achieved while avoiding unnecessary fatigue. 

2. Managing Fatigue and Injury Risk

TRIMP is crucial in tracking both acute (short-term) and chronic (long-term) training load. By comparing the Acute:Chronic Workload Ratio (ACWR), coaches can identify when an athlete is at an increased risk of injury due to sudden spikes or reductions in workload.  

3. Individualizing Training Programs

Every athlete responds differently to training. TRIMP enables individualized load monitoring, allowing coaches to tailor sessions to an athlete’s physiological capacity. For instance, endurance-focused players may accumulate TRIMP differently than sprint-based athletes, necessitating different recovery strategies. 

4. Optimizing Performance for Game Readiness

Teams can analyze TRIMP data from training and match days to ensure players are replicating game-like intensities in practice. If TRIMP values in training are significantly lower than those in competition, adjustments can be made to better prepare athletes for game-day demands. 

How to interpret TRIMP

TRIMP should be used as your measure of overall training load, primarily because it includes both an internal factor (%HRMax) and an external factor (Time). 

This means you get a bit of everything included within the TRIMP metric, which is what we’re looking for when seeking to quantify the total training load. Clearly, time is quite a broad variable to use when considering external load but it is still a very useful factor in this context. 

One important consideration when interpreting TRIMP data is that the same score can be achieved in a variety of ways. For example, a short but very intense session with a high %HRMax could accumulate the same total TRIMP as a longer, lower intensity session. This is why using TRIMP-per-minute (TRIMP / Session Duration) is a good idea to provide some more context to the intensity of the session. 

As a great measure of overall training load, TRIMP is a good basis upon which to model your Acute:Chronic Workload Ratio (ACWR). Indeed, this is the metric used within the Firstbeat Sports dashboard. 

TRIMP As a Measure of Intensity (TRIMP/min) 

Monitoring TRIMP-per-minute allows you to train as you play. This metric provides you with the information needed to replicate or exceed match intensities when desired. 

What is a high TRIMP score?

As mentioned above, matching a TRIMP score alone is probably not sufficient to replicate match demands as they can be accrued at varying rates. For example, a TRIMP of 100 would normally be considered ‘Moderate’ load. But if it was achieved over 90 minutes you’d have a TRIMP/min of 1.1 which is actually ‘Easy’ intensity. The same 100 TRIMP achieved over 45 minutes would be a TRIMP/min of 2.2 which is classified as ‘Hard’ intensity. 

Below are the approximate definitions for ‘Easy’, ‘Moderate’ and ‘Hard’ training: 

Guidelines for analyzing TRIMP and TRIMP/min.

Firstbeat has sports-specific TRIMP reference values for soccer, basketball, and ice hockey for men and women. You can find them inside our free training load guides here.

TRIMP is a powerful, objective measure that provides crucial insights into athlete workload. When combined with Firstbeat Sports’ advanced heart rate based analytics, teams can fine-tune training, manage injury risk, and optimize performance. By leveraging TRIMP effectively, coaches can ensure their athletes are training smart, recovering optimally, and performing at their peak when it matters most.