Elderly, Healthy
Conditions
Keywords
Caffeine, Physiological Effects of Drugs, Central Nervous System Agents
Brief summary
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.
Detailed description
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.
Interventions
DRUGCaffeine
Caffeine capsule 6 mg/kg given 1 hour before test
Sponsors
Herning Hospital
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
70 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Endurance measured on an ergometer bicycle | The tests started 1 h following placebo/caffeine |
Secondary
| Measure | Time frame |
|---|---|
| Isometric maximum arm flexion strength | The tests started 1 h following placebo/caffeine |
| Fatigue (Borg scale) during ergometer test | After 5 minutes biking and at exhaustion |
| Postural stability | The tests started 1 h following placebo/caffeine |
| Reaction time | The tests started 1 h following placebo/caffeine |
| Isometric endurance (arm flexion) | The tests started 1 h following placebo/caffeine |
| Biochemistry: lactate, catecholamines, insulin, free fatty acids, glucose | Before intervention; before cycling; after 5 minutes of cycling; and at exhaustion |
| Withdrawal symptoms | At the end of each test |
| Side effects | At the end of each test |
| Walking speed | The tests started 1 h following placebo/caffeine |
Countries
Denmark
Outcome results
None listed