Pace and heart rate are two essential metrics for understanding performance in endurance sports and fitness training. Pace refers to the rate of movement or activity, while heart rate is the number of times the heart beats per minute. These two are directly linked — as pace increases, so does heart rate.
Monitoring both allows athletes to train more efficiently, avoid overtraining, and measure improvements in endurance and overall cardiovascular fitness.
Measuring and Estimating Heart Rate and Heart Rate Zones
Heart rate can be tracked using fitness devices, heart rate monitors, or manually by checking the pulse at the wrist or neck. Two primary heart rate measures — Resting Heart Rate (RHR) and Maximum Heart Rate (MHR) — are often used to set training zones for specific exercise goals.
Typical Heart Rate Ranges
| Heart Rate Type | Description | Typical Range (bpm) | What It Indicates |
|---|---|---|---|
| Resting Heart Rate (RHR) | Heart rate at rest, measured after waking up or before activity | 60–100 (some sources suggest 50–90) | Lower RHR usually indicates better cardiovascular health |
| Maximum Heart Rate (MHR) | Highest number of beats per minute during intense exercise | Calculated as 220 – age | Used to determine training intensity levels |
A lower resting heart rate typically reflects more efficient heart function. However, if your resting heart rate is consistently below 50 bpm or above 90 bpm, it may be a sign of an underlying medical issue.
Calculating Training Heart Rate Zones
Although the most accurate way to measure MHR is through a cardiac stress test, most people use the simple formula:
MHR = 220 – age
This formula provides a practical estimate for setting heart rate training zones. The following table outlines common training zones and their benefits:
| Training Zone | % of MHR | Intensity Level | Training Benefit |
|---|---|---|---|
| Zone 1 – Recovery | 50–60% | Very light | Helps in recovery and fat metabolism |
| Zone 2 – Aerobic Base | 60–70% | Light to moderate | Ideal for building endurance and burning fat |
| Zone 3 – Tempo | 70–80% | Moderate to hard | Improves aerobic capacity and efficiency |
| Zone 4 – Threshold | 80–90% | Hard | Increases lactate threshold and stamina |
| Zone 5 – Anaerobic | 90–100% | Very hard | Builds speed, power, and sprint capacity |
For fat burning, training between 60–70% of MHR is generally considered optimal.
Aerobic vs. Anaerobic Exercise
The terms aerobic and anaerobic describe how the body produces energy during physical activity. They differ based on duration, intensity, and the body’s energy source.
| Type of Exercise | % of MHR | Duration | Energy Source | Examples |
|---|---|---|---|---|
| Aerobic | 70–80% | Sustained, long duration | Oxygen-based (fat + carbohydrates) | Jogging, cycling, swimming |
| Anaerobic | 80–90% | Short, intense bursts | Stored glycogen (without oxygen) | Sprinting, HIIT, heavy weightlifting |
During aerobic exercise, the body has enough oxygen to fuel muscles, allowing longer workouts.
During anaerobic exercise, oxygen supply is insufficient, and muscles use glucose for energy, producing lactate, which leads to fatigue and the burning sensation in muscles.
Threshold Training and Long-Distance Performance
For endurance athletes, finding the right balance between aerobic and anaerobic effort is critical.
- Aerobic threshold pace: The fastest pace sustainable primarily with oxygen-based energy.
- Anaerobic threshold pace: The point at which glycogen becomes the main fuel source and lactic acid begins to accumulate.
Training slightly below or at these thresholds helps athletes increase endurance and delay fatigue — a method known as threshold training.
| Type of Threshold | Description | Typical Heart Rate Level | Benefit |
|---|---|---|---|
| Aerobic Threshold (AeT) | Pace sustainable for long periods, mostly oxygen-based | ~70–80% of MHR | Builds endurance and fat-burning efficiency |
| Anaerobic Threshold (AnT or LTHR) | Point where lactic acid accumulates faster than it’s cleared | ~80–90% of MHR | Improves speed and stamina, delays fatigue |
Determining Aerobic and Anaerobic Thresholds
While laboratory tests offer the most precise measurements, thresholds can also be estimated using a 30-minute time trial:
- Run at maximum sustainable effort for 30 minutes.
- Record your average heart rate during the last 20 minutes — this is your anaerobic threshold heart rate (LTHR).
- Subtract 30 bpm from this value to estimate your aerobic threshold heart rate.
- If testing in a group setting, extend the trial to 60 minutes for accuracy.
Regularly training near these thresholds helps delay lactate buildup, allowing you to run farther, faster, and more efficiently.
Final Thoughts
Combining pace and heart rate tracking provides a complete picture of how your body responds to exercise. Whether your goal is to improve endurance, build speed, or manage training intensity, understanding these principles helps ensure every workout is effective and safe.