Enter Training Details
Example Data Table
| Session | Avg HR | Duration | sRPE | HRR% | Load | TRIMP |
|---|---|---|---|---|---|---|
| Recovery Ride | 118 bpm | 40 min | 3 | 48% | 120 | 30 |
| Tempo Run | 154 bpm | 50 min | 6 | 73% | 300 | 93 |
| Threshold Intervals | 166 bpm | 42 min | 8 | 82% | 336 | 99 |
| Long Endurance | 142 bpm | 95 min | 5 | 65% | 475 | 147 |
These sample values show how session duration, perceived effort, and heart rate change the final intensity picture.
Formula Used
1) Estimated Max Heart Rate
Max HR = 208 − (0.7 × Age)
2) Heart Rate Reserve Intensity
%HRR = ((Average HR − Resting HR) ÷ (Max HR − Resting HR)) × 100
3) Percent of Max Heart Rate
%Max HR = (Average HR ÷ Max HR) × 100
4) Session Load
Session Load = Duration in Minutes × Session RPE
5) TRIMP
TRIMP = Duration × HRr × 0.64 × e^(k × HRr)
Here, HRr is the heart rate reserve fraction. The factor k is 1.92 for men and 1.67 for women.
6) Pace and Speed
Pace = Duration ÷ Distance
Speed = Distance ÷ (Duration ÷ 60)
7) Relative Energy Rate
Relative Energy Rate = Calories ÷ (Body Weight × Duration in Hours)
How to Use This Calculator
- Enter age, resting heart rate, average exercise heart rate, duration, and session RPE.
- Add your real max heart rate if known. Otherwise, leave it blank for an age-based estimate.
- Enter distance to calculate pace and speed. Add calories and body weight for energy metrics.
- Click the calculate button to display results immediately above the form.
- Review HRR%, percent max HR, TRIMP, session load, pace, and energy output together.
- Use the CSV or PDF buttons to save the session report for later tracking.
Frequently Asked Questions
1) What does training intensity mean here?
This calculator defines intensity through heart rate reserve, percent max heart rate, perceived effort, and session stress. It helps you judge how demanding one workout was instead of looking at only pace or duration.
2) Why use heart rate reserve instead of only max heart rate?
Heart rate reserve includes your resting heart rate, so it reflects your usable training range better. That usually makes intensity zones more personalized than a simple percent of max heart rate.
3) What is session RPE?
Session RPE is your overall difficulty rating for the workout on a 0 to 10 scale. Multiplying it by duration creates a practical internal load score used by many coaches.
4) What does TRIMP tell me?
TRIMP estimates training impulse, which combines duration and cardiovascular strain. It is useful for comparing different workouts and monitoring accumulated fatigue across a week or training block.
5) Should I enter an estimated or tested max heart rate?
A tested value is usually better because age formulas are only rough estimates. If you do not have a tested number, the built-in estimate is still useful for general planning.
6) Can I use this for cycling, running, and rowing?
Yes. The heart rate, session load, and TRIMP parts work across many endurance activities. Pace and speed are most relevant when distance is entered and measured consistently.
7) Is a higher session load always better?
No. Higher load can improve fitness, but too much intensity too often may hurt recovery and consistency. Strong programming balances hard days, easier sessions, and adequate rest.
8) How often should I compare these values?
Compare them after every key workout and across each week. The real value comes from trends, such as gradually rising load, repeated very hard sessions, or improving pace at similar intensity.