The study investigated the effect of caffeine on physical performance in healthy citizens aged over 70 years following eight hours of abstinence from caffeine containing drinks and foods. The main hypothesis was that 6 mg/kg caffeine would improve cycling endurance at 65% of expected maximal heart rate.

It is well documented that caffeine ingestion increases the endurance of young people exercising at 60%-85% of their maximal oxygen uptake (13;15;47). It also seems to improve endurance as measured by repeated sub-maximal isometric contraction (42), and decreases the rate of perceived exertion during exercise (6;9;46). Typically, doses of approximately 6 mg/kg caffeine were used in these studies.

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.

Inclusion Criteria:

• Healthy elderly individuals aged over 70 years (Primarily those who previously have participated in an identical study with 48 hour caffeine abstinence)

Exclusion Criteria:

• Dementia or invalidating psychiatric disease
• General debility, angina, or other diseases that would render participation in the test program impossible
• Treatment with beta receptor blocking drugs, calcium-channel blocking drugs, digitalis, or nitroglycerine
• Acute disease and injury
• Diabetes
• Conditions that would contraindicate caffeine ingestion or participation in the test program
• Treatment with medication that interacts with caffeine
• Ingestion of caffeine containing drinks and foods 8 hours before each session