With a growing number of elderly with a physical active lifestyle and many elderly participating in rehabilitation programs the endurance enhancing effect of caffeine is of increasing interest in this age group. We therefore conducted a study of healthy 75 year old citizens to investigate whether 6 mg/kg caffeine improved physical performance and reduced the perceived effort during work in healthy citizens aged ≥ 70 years. The main hypothesis was that caffeine would improve cycling endurance at 65% of expected maximal heart rate. The study showed that compared to placebo caffeine increased endurance by 25 % (p<0.0001) and isometric sub-maximal strength with 54 % (p<0.0001), reduced perceived exertion after 5 minutes of biking by 11 % (p=0.002), but in 21 of 30 participants there was reduced postural stability (with eyes open). In the above described study participants abstained from caffeine containing drinks and foods for 48 hours prior to each test. Half of the participants reported withdrawal symptoms. Such a long caffeine abstinence period would infer with daily life for many people. We therefore invited the participants from the above study to a repetition of the above study to test whether similar results would be obtained if participants only abstained from caffeine containing drinks and foods for 8 hours prior to each test.