Caffeine and Sodium Citrate Ingestion

• Heart Rate [ Time Frame: during study phase of 3 week (4 tests) ] [ Designated as safety issue: No ]
  Heart Rate measured from 2min before the test until 5min after the 1500m-test.
• Lactate Concentration [ Time Frame: during the 3 weeks study phase ] [ Designated as safety issue: No ]
  1min before starting the warm up, 15s after the end of the warm up, 15s after completing the test, 2min/4min/6min/8min/10min after the test
• blood pH, sodium concentration and plasma bicarbonate [ Time Frame: during the 3 weeks of study phase ] [ Designated as safety issue: No ]
  1min before starting with the ingestion of the fluid, immediately before starting the warm up, just immediately before starting the 1500m test.
• Oxygen Consumption [ Time Frame: during 3 weeks of study phase ] [ Designated as safety issue: No ]
  oxygen consumption (VO2(ml/min/kg), VCO2(ml/min), RER (VCO2/VO2)) starting of the measurement is 2min before the start of the 1500m and ends 2min after having completed the 1500m
• rating of gastrointestinal stress [ Time Frame: during the 3 weeks of study phase ] [ Designated as safety issue: No ]
  1min before starting to drink the fluid, 2min before starting with the warm up, 2min before the test and 2min after having completed the 1500m
• Rating of Perceived Exertion (RPE) [ Time Frame: during the 3 weeks of study phase ] [ Designated as safety issue: No ]
  15s after the end of the warm up, 15s after having completed the 1500m

A positive ergogenic effect of sodium citrate and caffeine ingestion in a short-term, high-intensity exercise task was shown by several studies. These studies were conducted with healthy, able-bodied subjects.

The aim of the study is to investigate whether caffeine or sodium citrate ingestion could enhance performance in spinal cord injured wheelchair athletes. It is a double blind, placebo controlled and randomized study.

The athletes have to complete four 1500m tests on a training roller. Before each treatment they get different supplementations. Once they get sodium citrate and a placebo, once caffeine and a placebo, once sodium citrate and caffeine and for the fourth treatment they get twice a placebo. Two hours after starting with the supplementation they have to complete the 1500m as fast as possible. Time to complete 1500m, blood pH, plasma bicarbonate, sodium concentration, heart rate, oxygen consumption, blood lactate concentration and rate of perceived exertion (RPE) were measured.

• Dietary Supplements
• Heart Rate/Drug Effects
• Lactic Acid/Metabolism
• Physical Education and Training/Methods
• Wheelchairs

• Dietary Supplement: Caffeine
  gelatine capsule 6mg/kg bodyweight 60min prior test
• Dietary Supplement: Sodium Citrate
  0.5g/kg bodyweight diluted in 7dl water ingested 120-90min prior test
• Dietary Supplement: Mannitol
  gelatine capsule filled with mannitol (100mg per capsule) ingested 60min prior test
• Dietary Supplement: Sodium Chloride
  sodium chloride diluted in 7dl water 0.045g/kg bodyweight 120-90min prior test

• Active Comparator: Caffeine
  6mg per kg bodyweight ingested 60min before test
  Interventions:

  • Dietary Supplement: Caffeine
  • Dietary Supplement: Sodium Chloride
• Placebo Comparator: Placebo
  Sodium chloride and mannitol as placebo are ingested by the athlete
  Interventions:

  • Dietary Supplement: Mannitol
  • Dietary Supplement: Sodium Chloride
• Active Comparator: Sodium Citrate
  sodium citrate diluted in 7dl water, ingestion 120 to 90min prior test
  Interventions:

  • Dietary Supplement: Sodium Citrate
  • Dietary Supplement: Mannitol
• Active Comparator: Caffeine and Sodium Citrate
  sodium citrate 120-90min prior test capsules:60min prior test
  Interventions:

  • Dietary Supplement: Caffeine
  • Dietary Supplement: Sodium Citrate

Inclusion Criteria:

• wheelchair athletes
• national team
• category T53 and T54

Exclusion Criteria:

• medicated
• pregnant (for women)
• cardiovascular and respiratory diseases