• 11 – 14 April 2024
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06.01.2023, Andreas Barz

Endurance training – What trainers should look for in intensity control

Endurance training is a fundamental part of training for most people. However, training management – especially the choice of the right intensity – is often a “black box”. Qualified trainers should explain this to their clients and give them professional advice on how to train in a targeted manner using simple means.

Endurance training focuses on improving endurance, fatigue resistance and regeneration. Exercisers should be able to maintain the given load for as long as possible and recover quickly afterwards. Specific endurance training in fitness training is useful for all target groups. After all, how good one's endurance is becomes just as apparent when climbing up to the third floor as when running a half-marathon or completing several sets of squats.

Metabolic load in endurance training

Experience shows that weight reduction and improving general fitness are the dominant motives in health-oriented endurance training. In most cases, the training does not have a specific load requirement. Even though this approach can lead to success, it is important to have specific load targets in order to be able to make specific adaptations. In endurance training, metabolic stress plays a decisive role. Different load intensities influence the form of energy supply (aerobic vs. anaerobic) as well as the proportions of the different energy substrates (especially glucose vs. fatty acids).

Among other things, a higher metabolic demand is accompanied by an increase in lactate production (salt of lactic acid). If a lot of lactate is produced, the muscles can become over-acidic. This causes symptoms such as muscle pain or cramps. The differences in energy production are the main characteristics of different endurance training and their adaptation effects. Against this background, the classification of the different training ranges has become established.

In order to achieve a targeted metabolic demand, the intensity of the training is the decisive adjusting screw.

Intensity control in endurance training

Before a training plan can be set up, it must first be clarified what the reference value is for the load intensity. In strength training, for example, the one-repetition maximum (1-RM) or the multiple-repetition maximum (X-RM) are established as common reference values. In endurance training, on the other hand, intensity is often referred to as the percentage of maximum heart rate (HRmax). The actual HRmax, however, can only be determined through a workout. However, very few people fulfil the necessary health requirements for an endurance test. Another possibility is to determine the maximum heart rate using the rule of thumb (220 – age). However, this pragmatic alternative is quite imprecise because the heart rate can vary greatly even among people of the same age. In addition, it has been shown that when training at a certain fixed percentage of HRmax, there are significant differences in lactate production and metabolic stress.

Intensity specifications based on maximum heart rate can therefore clearly miss their purpose of achieving a certain training range. Nevertheless, intensity data is important because it provides a rough guide and can be easily measured using a heart rate monitor or fitness tracker. However, there are other options that trainers can use to guide intensity.

Determining training intensity based on performance

The following option for intensity control is primarily aimed at ambitious recreational athletes who have the health requirements for maximum exertion. The training range is based on the best time over a certain distance. 70 percent of the average speed of a ten-kilometre best time corresponds to the speed of a basic endurance training. For a maximum run over ten kilometres, the energy supply must physiologically take place in the upper range of the aerobic-anaerobic transition. A slower running speed therefore also leads to an increased aerobic energy supply. 

Intensity control with the help of the subjective feeling of exertion

The Borg scale is the most common way to measure the subjective feeling of exertion. The exerciser assigns the load a value from six (“very, very easy”) to 20 (“very, very hard”). When using subjective scales, it is important that trainers provide clear and descriptive reference points. A person who is just starting endurance training should perceive the effort of training as slightly higher compared to a brisk walk.

Inexperienced people in particular need regular, objective feedback. In addition to the subjective perception of exertion, trainers should also take into account the heart rate, the performance achieved and their own experience.

In this context, coaches can also consult the Talk Test as a tool. This test is based on the physiological mechanism in which talking is only possible to a limited extent in the anaerobic metabolic range. Although this approach may seem very trivial and imprecise at first, numerous studies have shown that training ranges at different performance levels can be precisely targeted by means of the Talk Test.


During endurance training, the intensity is often only controlled intuitively. However, individual intensity control can create targeted training effects. There are many ways to control the intensity of the load. Although the maximum heart rate serves as a rough guide, it must be checked individually. With the help of the subjective load sensation and the talk test, trainers have additional tools to control the load and set individual intensity targets. This enables trainers to design endurance training in a much more targeted way and to provide qualitative training advice.


About the author

Andreas Barz is a sports scientist specializing in health sports. He works as a lecturer, author and tutor at the German University for Prevention and Health Management (DHfPG) and as a speaker at the BSA Academy. As a passionate endurance athlete, he participates in long-distance triathlons, among other things.




Hottenrott, K. (2006). Training control with heart rate monitors (1st ed.). Aachen: Meyer & Meyer.

Neumann, G., Pfützner, A. & Berbalk, A. (2013). Optimized endurance training. Training planning, performance building, nutrition tips (7th ed.). Aachen: Meyer & Meyer.


This article first appeared in fitness Management.