EPOC (Sports Science)

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Excess post-exercise oxygen consumption.svg

EPOC (ger .: excess postexercise oxygen consumption , German: oxygen uptake more after work or Nachbrennwert ) is a term used in exercise physiology and is the oxygen uptake more than the rest needed addition to a physical load on. This is characterized by increased breathing .

Physiological background

After the start of physical activity, the cardiovascular and respiratory systems only adapt to the increased oxygen demand with a delay and only reach a steady state after a few minutes . This leads to an oxygen deficit . However, when measuring the amount of rebreathed O 2 , it is found that in most cases the amount is greater than the actual deficit. During and after exercise, processes take place in the body that require additional oxygen.

The EPOC does not, as previously assumed, correspond to the initial oxygen deficit, but is more a sign of the strain on the body and the regeneration required as a result . The level of the EPOC depends on the duration and intensity of exercise. In addition to the increased oxygen uptake, an increased energy consumption of the body can be determined, which is mainly characterized by fat burning .

The decrease in the O 2 uptake curve after the end of the exercise shows an almost exponential course. A distinction can be made between three phases during which, among other things, various processes to restore homeostasis take place:

phase Half-life Approximate oxygen demand Processes
1 30 s 1.5-2 l
2 15 minutes 4–4.5 l
3 12-24 h 20 l

A total of around 26 liters of O 2 are rebreathed within 12 hours . Increased oxygen uptake can be determined up to 38 hours after exercise. The exercise intensity plays a smaller role for the increased oxygen intake than the duration of the exercise. The effect of the EPOC occurs in both aerobic and anaerobic stresses, with anaerobic stress leading to higher EPOC values ​​than aerobic stress with the same amount of work done.

meaning

After exercise, trained people show a faster decrease in oxygen uptake than untrained people, which speaks for a better ability to regenerate. There is also a strong correlation between the intensity of an exercise and the strength and duration of the EPOC. This value can thus be used for performance diagnostics, e.g. B. to examine the current endurance capacity or to check the individual strain of a load during training and thus to avoid under- or overtraining .

Since energy consumption is increased in the phase after exercise and the need is partly covered by burning fat, EPOC is important in weight reduction training programs.

Determination of the EPOC

Direct measurement

The direct value of the EPOC is measured by means of spiroergometry , i.e. by examining the breathing gases under stress with an ergometer . The area under the oxygen consumption at rest is subtracted from the area under the oxygen consumption after the exercise. The value is usually given in ml / kg.

Indirect calculation

It is possible to calculate the EPOC value indirectly from the heart rate . The advantage of this method is the relatively low effort, since only a heart rate monitor with the evaluation software is required. In addition, the EPOC can be calculated at any point in time of stress and thus represents the current stress of the athlete.

Oxygen debt

Earlier it was with oxygen debt ( English O 2 -debt ) the volume of oxygen referred to, in order to easily work, the dynamic O which are added after the end of a load from the body in addition 2 to compensate for production deficit. The term oxygen debt is no longer used today because the amount of oxygen that is breathed in is usually greater than the oxygen deficit.

Oxygen debt is only to be used if it is about the re- phosphorylation of creatine to creatine phosphate and thus to replenish the energy-rich phosphates .

See also

Individual evidence

  1. ^ Wildor Hollmann and Theodor Hettinger: Sports medicine. 4th edition, Schattauer, Stuttgart 2000, ISBN 3-7945-1672-9 , p. 69
  2. Jürgen Weineck: Sports biology. 10th edition, Spitta, Balingen 2010, ISBN 978-3-938509-25-8
  3. a b c d Horst de Marées: Sports Physiology. 9th edition, Sportverlag Strauss, Cologne 2003, ISBN 978-3-939390-00-8 , pp. 376–378
  4. a b Glenn A. Gaesser, George A. Brooks: Metabolic bases of excess post-exercise oxygen consumption: a review. Medicine And Science In Sports And Exercise , 1984, Vol. 16, Issue 1, pp. 29-43
  5. E. Børsheim & R. Bahr: Effect of exercise intensity, duration and mode on post-exercise oxygen consumption. In: Sports Medicine 33 (14): 1037-60
  6. ^ R. Bielinski, Y. Schutz, E. Jéquier: Energy metabolism during the postexercise recovery in man. The American Journal of Clinical Nutrition 42 (1): 69-82. Online full text
  7. Sverre Maehlum, Michèle Grandmontagne, Eric A. Newsholme, Ole M. Sejersted: Magnitude and duration of excess postexercise oxygen consumption in healthy young subjects. In: Metabolism , 1986, Vol. 35, Issue 5, pp. 425-429
  8. MD Schuenke, RP Mikat, JM McBride (2002): Effect of an acute period of resistance exercise on excess post-exercise oxygen consumption: implications for body mass management. In: European Journal of Applied Physiology 86 (5): 411-7.
  9. Schmidt, Wilfred Daniel (1992): The effects of aerobic and anaerobic exercise on resting metabolic rate, thermic effect of a meal, and excess postexercise oxygen consumption. Ph.D. dissertation, Purdue University, United States - Indiana. Retrieved March 30, 2011, from Dissertations & Theses
  10. Kevin R. Short; Darlene A. Sedlock: Excess postexercise oxygen consumption and recovery rate in trained and untrained subjects. In: Journal of Applied Physiology , 1997, Vol. 83, Issue 1, pp. 153-159
  11. a b c Firstbeat Technologies Ltd. (2012): Indirect EPOC Prediction Method Based on Heart Rate Measurement. (Online full text) (PDF; 941 kB). Retrieved July 21, 2012.
  12. Jeff M. Reynolds and Len Kravitz, Ph.D .: Resistance Training and EPOC Online Full Text ( Memento of the original from April 21, 2005 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . Retrieved July 21, 2012. @1@ 2Template: Webachiv / IABot / www.drlenkravitz.com
  13. Cunningham & Faulkner 1969, p. 68