Basic endurance

What is basic endurance?

From a physiological point of view, basic endurance can be defined as the ability to perform physically over a while by having the physiological capacity to perform more (5). Basic endurance is particularly important in cyclical movements, such as swimming, running, and cycling. It is also one of the five main motor demands (2): 

1. Endurance
2. Strength
3. Flexibility
4. Coordination
5. Speed

What types of basic endurance are there? 

Basic endurance can be divided into different load times and the energy demand at maximum endurance load. A distinction is made between basic endurance 1 and basic endurance 2. What differentiates the various forms of basic endurance 1 and 2 are the limitations they experience due to the systems involved. 

Specifically, the lung diffusion capacity, the maximum cardiac output, the oxygen transport capacity of the blood, and the oxygen uptake (capillarization) of the muscles under load (4). It is therefore the oxygen-transporting systems that are most challenged and where the most pronounced adaptive responses can be found (1). Consequently, the maximum endurance performance limit is at the aerobic threshold (3). 

Basic endurance 1 
Basic endurance 1 also known as LIT (low intensity) takes place at a very low intensity so that the muscles being exercised have enough oxygen available to metabolize fat. A well-trained fat metabolism allows the body to draw on an almost unlimited energy store during exercise. As a result, performance can be maintained for longer and at the same time, the limited carbohydrate stores in the muscles are spared.

Basic endurance 2
Basic endurance 2 training takes place at a higher intensity below the aerobic-anaerobic threshold. Here the body no longer gains energy mainly from fat, but also the carbohydrates stored in the muscles. The energy production from carbohydrates creates the by-product lactate, which, however, does not yet accumulate here because the muscles break down at least as much lactate as they produce.
Basic endurance 2 training helps you to maintain higher speeds for a longer time and to deal with the lactate produced in the body. 

Limiting factors of basic endurance:

According to Basset & Howley (2000), basic endurance is based on three limiting factors: 

1. Maximum Oxygen Uptake (VO2max) 
   The athlete's VO2max represents the amount of oxygen that can be absorbed per minute by the working muscles.
2. Prozentsatz der VO2max (%VO2max)
   Percentage utilization of VO2max at the aerobic - anaerobic threshold.
3. Mechanical efficiency
   This is defined as the oxygen or energy cost: for every 1 liter of oxygen, about 20 kJ of energy is used to maintain power or speed

Thus, basic endurance is based on metabolic function as well as mechanical function, each of which can be broken down into smaller subunits.
The metabolic function includes the factors of heart rate, cardiac output, and maximal oxygen uptake. You can read about how these factors relate to each other in our blog post on VO2max .

Mechanical function depends on the quality of muscle strength, neural innervation, and muscle structure (fiber type content, mitochondrial density) (5). 

The goal of an endurance athlete must be to train the quality of the musculature in a sport-specific way so that it can work as efficiently as possible. As soon as the muscles can use as little energy as possible, the body can perform better. 

How do I train my basic endurance?

To increase basic endurance, studies recommend doing 80% of the training in basic endurance 1 and 20% intensive training (6). 

This is called "polarised training", which is the polarised load ratio between long regenerative and short intense training. 

To understand exactly how polarised training works, one must first get an overview of the different load zones. In training science, there are often three load zones, which are classified as follows (7): 

Zone	1	2	3
Intensity	low	moderate	high
%HRmax	70	80	90
Duration (min)	60 – 120	60	15 – 30

In addition to regular basic endurance training, training scientists recommend up to two high intensive Sessions (HIT; zone 3) per week. If too much intensive training is done, regeneration is usually neglected, which plays a very important role in the success of an athlete (8): "work + rest = success".

Sources

1. Bassett, D.R. & Howley, E.T. (2000). Limiting factors for maximum oxygen uptake and determinants of endurance performance. Med Sci Sports Exerc (32): 70-84.
2. Bös, K. (2006). Motorische Leistungsfähigkeit von Kindern und Jugendlichen. In: W. Schmidt, I. Hartmann-Tews, W. D. Brettschneiter (Hrsg.). Erster deutscher Kinder- und Jugendsportbericht. (S.85-108). Schorndorf: Hofmann Verlag.
3. Dickhuth, Hans-Hermann (2000). Einführung in die Sport- und Leistungsmedizin. Verlag Karl Hofman: Schorndorf.
4. Hollmann, W. (Hrsg.): Zentrale Themen der Sportmedizin im Sport. Springer-Verlag: Berlin, Heidelberg, New York 1991.
5. Norman, D. (2014). Establishing Endurance for Reperated Performance. High-Performance Training for Sports.
6. Seiler, S. (2010). What is the best practice for training intensity and duration distribution in endurance athletes? International Journal of Sports Physiology and Performance. 5(3): 276-291.
7. Stöggl, T. L. & Sperlich, B. (2015). The training intensity distribution among well-trained and elite endurance athletes. Front. Physiol. 6:295.
8. Vestegen, M. & Williams, P. (2005). The Core Performance: Revolutionary Workout Program to Transform Your Body & Your Life. Emmaus: Rodale Books.