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?
- 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)
- 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!
- Kraus, W. (2014). Ergogene Substanzen: Ausgewählte Nahrungsergänzungen für den Ausdauersportler. disserta Verlag.
- Ivy, J. L., Costill, D., Fink, W., & Lower, R. (1979). Influence of caffeine and carbohydrate feedings on endurance performance. Pulse, 1620(16.18), 1693.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- Ferrauti, A., Pieper, S., Seeber, K., & Weber, K. (2002). Keine Leistungssteigerung durch Koffein bei Intervallarbeit in den Sportspielen?. DEUTSCHE ZEITSCHRIFT FÜR SPORTMEDIZIN, 53(5).
- Bruce, C. R., Anderson, M. F. (2000). Enhancement of 2000m rowing performance after caffeine ingestion. Medicine & Science in Sports and Exercise, 32: 1958-1963.
- Graham, T. E. (2001). Caffeine, coffee and ephedrine: impact on exercise performance and metabolism. Canadian Journal of Applied Physiology, 26(S1), S186-S191.
- 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.