Pulse – all you need to know
Max pulse is often used as a reference for training intensity. There is however a limitation related to this. Very few people have actually measured their max pulse. There are some rules of thumb on how to calculate it, but the results are inaccurate, and may lead to wrong intensity and training. My recommendation is to forget about the term max pulse, since it is uninteresting. The threshold pulse is something else, since it can be trained for and is more important to consider. By using this, you will get a more correct intensity in the training.
Here are some terms related to pulse that are useul to know something about:
Max pulse can be defined as the maximum times the heart can beat during one minute. The upper limit is genetically decided, so the max pulse is not possible to train. It is just a number, which changes frequently during the life. It is inaccurate for training purposes, and you really don’t need to know it. The threshold pulse is what you should focus on. Max pulse should not be confused with VO2 max, which is a measure of your body’s maximal oxygen uptake ability. Go to our VO2 max article to read more about this.
Threshold pulse / anaerobe threshold
The threshold pulse is the most important reference when training endurance. The threshold, degree of utilisation, anaerob threshold, acid limit and lactate threshold are different terms for more or less the same thing. How do I find my threshold pulse? Just to be clear, it is not ONE defined pulse, let’s say 165. The threshold pulse will be within a range of pluss/minus 1 to 2 heart beats, for examle 163 to 167 beats, roughly estimated. The target of training will then be to raise/increase the threshold pulse and then also the threshold speed of running. We know that the current shape varies from day to day, and so does the threshold pulse. Here I will give you a simple explanation of what the threshold pulse and threshold load actually are.
The threshold load is the maximal load you can achieve where there is a balance between production and removal of lactic acid in the blood. We always have a level of lactic acid in our blood. Even at resting, the level is 1 til 1,5 (millimol/l.) At threshold load you will therefore have the threshold pulse, and you are working at a “biochemical balance” with a constant level of lactic acid. A commonly used reference for lactic acid level at threshold is 4 milllimol/l.
If the load is reduced to below the threshold, the level of lactic acid decreases and stabilises on a lower level, when the load is even. If the load increases above the threshold, the level of lactic acid increases. But at a load above the threshold, something else happens. The lactic acid level do not stabilise at a higher level, but increases steadily, even if the load is even. Recent research has found that the liver is not able to remove enough lactic acid at loads over the threshold. The reason for this is that the the bloodstream is prioritised to the muscles, leading to less blood to the liver, and consequently less capacity to remove the lactic acid.
A good advice related to threshold is to monitor your breathing. At threshold, the breath is uncomfortable, but it is steady, and you can manage it. When you get above the threshold level, breathing is more and more uncomfortable and you will start hyperventilating. This is actually a good way to find your threshold, if you do it in a controlled way with somebody who knows how to do it.
Falling pulse during interval sessions also gives a good indication if you have the right load. Falling pulse means how much the pulse drops in the pauses during an interval/fartlek session. The load is right if the pulse drops some strokes during the pause. It is normal if it drops less during the pauses in the last sessions. If the pulse does not drop in the pause, in particular in the first sessions, you are training too hard.
Resting pulse is the lowest heart rate you have while resting. The stronger your heart is,the less strokes it needs to pump blood, consequently the resting pulse will be lower. In opposite to max pulse, the resting pulse is possible to train. It becomes lower the better shape you are in. It is best to measure your resting pulse in the morning, before you start to be active (provided that you do not wake up because of an alarm clock that sends your pulse to the skies….). Rest for a few minutes after waking up, and then measure the pulse with a pulse watch. Sickness and being overtrained shows quite similarly on the resting pulse, making it to increase quite significantly, around 5-10 strokes more than normal. If you follow your resting pulse you will be able to see if and when you are recovered and ready for a new training session, or if you should take it easy.
Training is fun and should not be made too complicated. The simplest way is very often the best way!
Authors: Ingrid & Arve Kristiansen, Marte Kristiansen