Training Load Calculator

Training Load Calculator – TRIMP, sRPE & ACWR Explained

The Training Load Calculator is a performance monitoring tool that helps athletes, coaches, and fitness professionals quantify how much physiological stress the body experiences during training. By combining three globally accepted models — TRIMP, sRPE, and ACWR — this calculator provides a complete picture of short-term fatigue, long-term adaptation, and injury risk.

Whether you are a runner building mileage, a footballer managing weekly sessions, a cyclist tracking endurance load, or a strength athlete controlling intensity, training load monitoring is the foundation of sustainable performance. Training harder does not always mean training smarter — proper load distribution is what prevents burnout and injuries.

What Is Training Load?

Training load is the numerical representation of how much stress a training session places on your body. It reflects not only how long you trained, but also how hard your body worked internally. Unlike distance or weight alone, training load captures physiological strain.

• Improves long-term performance planning
• Reduces injury and overtraining risk
• Tracks fatigue accumulation
• Optimizes recovery days
• Prevents sudden spikes in workload

The Three Training Load Models Used

This calculator integrates the three most widely used scientific models:

• TRIMP – Heart-rate based internal load
• sRPE – Perceived exertion based load
• ACWR – Short-term vs long-term workload ratio

1. TRIMP – Training Impulse Model

TRIMP (Training Impulse) was developed by Dr. Eric Banister and is one of the oldest and most trusted methods for quantifying cardiovascular training stress. It uses heart rate data to assess how hard the body worked during a session.

Where:

• Duration = Training time in minutes
• HR Ratio = Average HR ÷ Maximum HR
• k = 1.92 for males, 1.67 for females

What TRIMP Tells You

• Cardiovascular stress level
• Internal training strain
• Heart-rate driven fatigue
• Aerobic training adaptation

TRIMP Load Categories

• < 100 → Low Load
• 100 – 200 → Moderate Load
• 200 – 300 → High Load
• > 300 → Very High Load

TRIMP is especially useful for endurance athletes such as runners, cyclists, rowers, swimmers, and triathletes.

2. sRPE – Session Rating of Perceived Exertion

sRPE is one of the simplest and most powerful training load models used in team sports, fitness training, and strength conditioning. It is based entirely on how hard the session *felt*.

Why sRPE Is Powerful

• Captures both physical and mental stress
• Works for any sport
• No heart-rate monitor required
• Used by professional sports teams
• Tracks cumulative fatigue

sRPE Load Interpretation

• < 300 → Low Load
• 300 – 600 → Moderate Load
• 600 – 900 → High Load
• > 900 → Very High Load

This model works exceptionally well for football, basketball, CrossFit, martial arts, gym training, and mixed-intensity sports where heart rate alone is not enough.

3. ACWR – Acute:Chronic Workload Ratio

ACWR is the most powerful injury-risk monitoring method in modern sports science. It compares what you did recently (acute load) with what your body is used to (chronic load).

• Acute Load: Last 7 days of training
• Chronic Load: Rolling 28-day average

ACWR Risk Zones

• < 0.8 → Undertraining Risk
• 0.8 – 1.3 → Safe Training Zone
• 1.3 – 1.5 → Elevated Injury Risk
• > 1.5 → High Injury Risk

ACWR protects athletes from sudden workload spikes — the number one cause of non-contact injuries.

Why You Should Use All Three Models Together

• TRIMP measures cardiovascular stress
• sRPE measures total perceived fatigue
• ACWR measures injury risk progression

Using all three together gives a complete training stress profile for optimal performance.

Who Should Use This Training Load Calculator?

• Runners & endurance athletes
• Team sport players and coaches
• Personal trainers & strength coaches
• Fitness enthusiasts
• Rehabilitation programs
• Sports scientists