# Triathlon Target Heart Rate Calculator

URL: https://speedycalculator.com/calculators/sports/triathlon-target-heart-rate/
Last updated: 2026-10-30

> The triathlon target heart rate calculator gives five Karvonen heart rate zones for running, and sport-adjusted zones for cycling and swimming, from your maximum (or age-estimated) and resting heart rate.

## Inputs

- Age (years)
- Measured running maximum heart rate (0 = estimate)
- Resting heart rate (bpm)
- Sport

## Results

- Maximum heart rate for this sport
- Heart rate reserve
- Zone 1 – Recovery (50–60%) from
- up to
- Zone 2 – Endurance (60–70%) from
- up to
- Zone 3 – Tempo (70–80%) from
- up to
- Zone 4 – Threshold (80–90%) from
- up to
- Zone 5 – VO₂ max (90–100%) from
- up to

## Formula

```
Target = RHR + % × (HRmax − RHR) · Cycling HRmax ≈ run HRmax − 5 bpm · Swimming HRmax ≈ run HRmax − 12 bpm
```

## Explanation

Your heart rate runs lower on the bike and lower still in the water: less muscle mass is working, you're horizontal and the water cools you. Triathletes should use separate zones for each sport.

### How to use the Triathlon Target Heart Rate Calculator

- **Age (years)**
- **Measured running maximum heart rate (0 = estimate)**
- **Resting heart rate (bpm)**
- **Sport**

Results update as you type, every field has its own unit menu, and everything is calculated in your browser.

### How it works

Enter your age or measured maximum heart rate and your resting heart rate, then choose the sport.

### Tips

- Practise transitions – they count towards your total time.
- Train your race-day nutrition as carefully as your fitness.
- Heart rate zones differ slightly between swimming, cycling and running.
- Everything is calculated in your browser.

### Common mistakes to avoid

- Going too hard on the bike and suffering on the run.
- Trying new food or gear on race day.
- Ignoring open-water skills.

### Inputs explained

FieldWhat to enterAge (years)A numberMeasured running maximum heart rate (0 = estimate)A numberResting heart rate (bpm)A numberSportChoose one: Running, Cycling, Swimming

### What each result means

- **Heart rate reserve** = [Maximum heart rate for this sport] - [Resting heart rate (bpm)]
- **Zone 1 – Recovery (50–60%) from** = round([Resting heart rate (bpm)] + 0.5×[Heart rate reserve])
- **up to** = round([Resting heart rate (bpm)] + 0.6×[Heart rate reserve])
- **Zone 2 – Endurance (60–70%) from** = round([Resting heart rate (bpm)] + 0.6×[Heart rate reserve])
- **up to** = round([Resting heart rate (bpm)] + 0.7×[Heart rate reserve])
- **Zone 3 – Tempo (70–80%) from** = round([Resting heart rate (bpm)] + 0.7×[Heart rate reserve])
- **up to** = round([Resting heart rate (bpm)] + 0.8×[Heart rate reserve])
- **Zone 4 – Threshold (80–90%) from** = round([Resting heart rate (bpm)] + 0.8×[Heart rate reserve])
- **up to** = round([Resting heart rate (bpm)] + 0.9×[Heart rate reserve])
- **Zone 5 – VO₂ max (90–100%) from** = round([Resting heart rate (bpm)] + 0.9×[Heart rate reserve])
- **up to** = round([Resting heart rate (bpm)] + 1.0×[Heart rate reserve])

### Example values

How the main result changes when **Age** changes and everything else stays at the example values above:

Age (years)Zone 2 – Endurance (60–70%) from (bpm)17.513926.251363513243.7512852.512570117

## Worked example

Inputs — Age (years): 35; Measured running maximum heart rate (0 = estimate): 0; Resting heart rate (bpm): 55; Sport: Running.

Results — Maximum heart rate for this sport = 184 bpm; Heart rate reserve = 129 bpm; Zone 1 – Recovery (50–60%) from = 119 bpm; up to = 132 bpm; **Zone 2 – Endurance (60–70%) from = 132 bpm**; up to = 145 bpm; Zone 3 – Tempo (70–80%) from = 145 bpm; up to = 158 bpm; Zone 4 – Threshold (80–90%) from = 158 bpm; up to = 171 bpm; Zone 5 – VO₂ max (90–100%) from = 171 bpm; up to = 184 bpm.

## Key terms

- **Karvonen**: Zones using heart rate reserve.

## FAQ

**Why are swimming zones lower?**
Horizontal position, cool water and less muscle mass lower your heart rate.

**Can I use running zones on the bike?**
They'll be about 5–10 bpm too high.

**Which zone for long training?**
Zone 2 builds endurance efficiently.

**Should I race by heart rate?**
It helps in long races; also use pace and power.


## Sources

- [American Heart Association – Target heart rates](https://www.heart.org/en/healthy-living/fitness/fitness-basics/target-heart-rates)
- [Joe Friel – The Triathlete's Training Bible](https://joefrieltraining.com/)