Caffeine in endurance sports – Part 1

Today’s #ScienceFriday is about the effect of caffeine on our physical performance. You will learn how caffeine affects our cardiovascular and nervous systems.

How does caffeine affect our body?


  • Cardiovascular system: 
  • Blood vessels dilate 
  • Increased cardiac output 
  • Systolic and diastolic blood pressure increase by 10 mm/HG (for about 3h)
  • Increased excretion of liquids (diuresis) and electrolytes

Central nervous system: 

  • Improved learning processes and memory 
  • Reduction of false coordination reactions 
  • Improved reaction times 

Research data on the effect on physical performance (25 studies)

17 studies found an ergogenic (performance-enhancing) effect; 8 found no significant difference:

  • Improvement of endurance performance, fat burning (2, 3, 4, 7)
  • Improved maximum performance (5)
  • Improved swimming performance (6, 8) 
  • Improved precision in tennis (9)
  • Improved rowing performance (10)

What is the necessary caffeine dose to note an ergogenic effect?

  • Minimum of 2,1 mg/kg 
  • From 3 mg/kg most significant improvement in endurance performance (12)
  • From 9 mg/kg overdose symptoms (11)

How does caffeine affect performance?

Energy production: 

  • Significant increase of free fatty acids (FFA) in the blood
  • In the first 15 – 20 minutes of exercise: energy production by FFA
  • Glycogen reserves in the muscles are conserved at the beginning
  • Improvement of the endurance load between 20% and 50% (laboratory) (1)

Nervous system:

  • Increased neurotransmitters (adrenalin, serotonin, dopamine)
  • Increased activity of motor neurons -> more muscle fibers contract 
  • mehr Muskelfasern kontraktieren
  • Subjective perception of fatigue is delayed (1)

Did you know?

Until 01.01.2004 ≥12 μg/ml caffeine in urine was considered doping!


  1. Kraus, W. (2014). Ergogene Substanzen: Ausgewählte Nahrungsergänzungen für den Ausdauersportler. disserta Verlag.
  2. Ivy, J. L., Costill, D., Fink, W., & Lower, R. (1979). Influence of caffeine and carbohydrate feedings on endurance performance. Pulse, 1620(16.18), 1693.
  3. Butts, N. K. & Crowell, D. (1985). Effect of caffeine ingestion on cardiorespiratory endurance in men and women. Research of Exercise and Sports, 56: 301-305.
  4. Sasaki, H., Maeda, J., Usui, S., & Ishiko, T. (1987). Effect of sucrose and caffeine ingestion on performance of prolonged strenuous running. International journal of sports medicine, 8(04), 261-265.
  5. Anselme, F., Collomp, K., Mercier, B., Ahmaidi, S., & Prefaut, C. (1992). Caffeine increases maximal anaerobic power and blood lactate concentration. European journal of applied physiology and occupational physiology, 65(2), 188-191.
  6. Collomp, K., Ahmaidi, S., Chatard, J. C., Audran, M., & Prefaut, C. (1992). Benefits of caffeine ingestion on sprint performance in trained and untrained swimmers. European journal of applied physiology and occupational physiology, 64(4), 377-380.
  7. Wiles, J. D., Bird, S. R., Hopkins, J., & Riley, M. (1992). Effect of caffeinated coffee on running speed, respiratory factors, blood lactate and perceived exertion during 1500-m treadmill running. British journal of sports medicine, 26(2), 116-120.
  8. MacIntosh, B. R., & Wright, B. M. (1995). Caffeine ingestion and performance of a 1,500-metre swim. Canadian Journal of Applied Physiology, 20(2), 168-177.
  9. Ferrauti, A., Pieper, S., Seeber, K., & Weber, K. (2002). Keine Leistungssteigerung durch Koffein bei Intervallarbeit in den Sportspielen?. DEUTSCHE ZEITSCHRIFT FÜR SPORTMEDIZIN, 53(5).
  10. Bruce, C. R., Anderson, M. F. (2000). Enhancement of 2000m rowing performance after caffeine ingestion. Medicine & Science in Sports and Exercise, 32: 1958-1963.
  11. Graham, T. E. (2001). Caffeine, coffee and ephedrine: impact on exercise performance and metabolism. Canadian Journal of Applied Physiology, 26(S1), S186-S191.
  12. Pasman, W. J., Van Baak, M. A., Jeukendrup, A. E., & De Haan, A. (1995). The effect of different dosages of caffeine on endurance performance time. International journal of sports medicine, 16(04), 225-230.

Similar Posts