[Flow]

Zitat von alessandro_gato

Ich würde an Eurer Stelle überhaupt kein Koffein nehmen.

http://www.fid-gesundheitswissen.de/...ein/102904333/


Sportlerherzen mögen kein Koffein:

http://www.medizin.de/ratgeber/koffein-kaffee.html

Dabei ging's wohl um die alte Kaufmann-Studie.

Caffeine Decreases Exercise-Induced Myocardial Flow Reserve

Objectives

We studied the acute effect of caffeine on myocardial blood flow (MBF) at rest and exercise in healthy volunteers at normoxia and during acute exposure to simulated altitude.

Conclusions

In healthy volunteers, a caffeine dose corresponding to two cups of coffee (200 mg) significantly decreased exercise-induced MFR at normoxia and was even more pronounced during exposure to altitude.

2009 kam eine weitere dieser Gruppe :

Caffeine impairs myocardial blood flow response to physical exercise in patients with coronary artery disease as well as in age-matched controls.



Hier ein Review der aktuellen Studienlage :

Caffeine Reduces Myocardial Blood Flow During Exercise

Abstract

Caffeine consumption has been receiving increased interest from both the medical and lay press, especially given the increased amounts now available in energy products. Acute ingestion of caffeine usually increases cardiac work; however, caffeine impairs the expected proportional increase in myocardial blood flow to match this increased work of the heart, most notably during exercise. This appears to be mainly due to caffeine's effect on blocking adenosine-induced vasodilatation in the coronary arteries in normal healthy subjects. This review summarizes the available medical literature specifically relating to pure caffeine tablet ingestion and reduced exercise coronary blood flow, and suggests possible mechanisms. Further studies are needed to evaluate this effect for other common caffeine-delivery systems, including coffee, energy beverages, and energy gels, which are often used for exercise performance enhancement, especially in teenagers and young athletes.