How many amateur runners have not wondered at least once whether they should run in training guided by heart rate or running pace. Which is the right one? Is there a right and a wrong answer to this question?

Is it right to run in workouts based on heart rate or pace?

In the above question, we cannot say that one of the two is correct. Both are correct. The determination of the aerobic and anaerobic threshold is based on heart rate. Therefore, in each workout we can define a range of heart rates that we must work. Heart rates correspond to specific running speeds. Therefore, a correlation can be made between the two values. By starting the run, we can reach a running speed that corresponds to the heart rates that we want to work or run, checking that our heart rates are within the training limits that we set.

This would make it quite easy to determine the pace of training. But what happens when the fatigue factor comes into play? During training, fatigue becomes more intense. If we run at the same pace, our heart rate increases due to fatigue. If we run based on our heart rate and keep it constant, our running pace drops due to fatigue.

Therefore, it is very easy during training to go outside the heart rate limits that we should run at if we do not calculate how fatigue affects heart rate and end up not progressing optimally until the end.

Ultimately, what is safer to perform the workout correctly? Running based on pace or heart rate?

The safest way to properly perform training is to run with the running pace as a guide. If we assume that we will have the heart rate as a guide, it is easy to start running with higher heart rates than the lower limit required by the training. Thus, there is a high probability of exceeding the upper limit of the training before it reaches its end. Even if we were not completely calm during training, we may momentarily raise our heart rates that will not correspond to our running pace. This is more likely to happen to amateur runners.

Therefore, in order to perform the training correctly, the ideal is to find the running pace that will correspond to the lower limit of the heart rate range that we want to run. So at the end of the training while running at the same pace the heart rate should reach the upper limit without exceeding it. Repetitions and break time also play a role. The break time must be sufficient so that the heart rate drops before the next fast run and is within the heart rate range that we have set during it, for the same running pace until the last repetition. The graphs below show the heart rate in relation to the running pace during an interval training that will be performed correctly.