Theory to practice - 'Bicarb loading' and team sports
Issue: Volume 28 Number 2
Background
A limiter in sports performance is when the exercising muscles become too acidic. Apart from quality and specific training, coaches and athletes are always looking for that ‘edge’ over their competition, to minimise the decrease in performance that accompanies muscles becoming acidic. Historically, sport science has shown that all-out efforts of 1–7 minutes in duration (for example, rowing, 200–400-metre swims, 800–1500-metre runs) can benefit from the legal practice of ‘bicarbonate loading’. But what about bicarb’s effect on team playing performance? Recent research from our own Australian Team Sport Research Group within the School of Human Movement and Exercise Science at the University of Western Australia has suggested it may work in team sports.
Research
The purpose of the study was to assess the effects of sodium bicarbonate (NaHCO 3) ingestion on a prolonged, intermittent-sprint test on a cycle ergometer that mimicked team sport performance. Seven female team-sport athletes (19 +/- 1 years, VO 2peak = 45.3 +/- 3.1 ml/kg/min) took two doses of either 0.2 g of NaHCO 3 or 0.138 g of NaCl (placebo) per kilogram of bodyweight 90 and 20 minutes before performing a bike test. The ‘test’ was two 36-minute ‘halves’ of repeated blocks of all-out 4-second sprints, followed by 100 seconds of active recovery at low intensity and 20 seconds of rest. Blood samples were taken from the ear lobe before ingestion, and before, during and after each half of the bike test and measured for bicarbonate concentration. VO 2 and total work completed were also recorded at regular intervals throughout the test.
Findings
Resting blood bicarbonate concentration was significantly higher after bicarb ingestion, compared to the placebo of sodium chloride. It remained higher during the bike test. There was also a trend toward improved total work in the second half of the bike test after the ingestion of the bicarb. Furthermore, the athletes completed significantly more work in seven of the 18-second-half, four-second sprints after taking the bicarb.
Coaches’ takeout
The results of this study suggest that bicarb loading might improve intermittent-sprint performance and may be a useful and legal supplement for team-sport athletes. Coaches and athletes, under the supervision of their sports science advisor (exercise physiologist, sports dietitian, sports physician), need to experiment with it to see if it works for their players. In particular, bicarb loading can lead to gut upsets, particularly in the rear end!
Reference
Bishop, D and Claudius, B 2005, ‘Effects of induced metabolic alkalosis on prolonged intermittent-sprint performance’, Medicine and Science in Sports and Exercise, 37(5), pp. 759–67.
The Australian Institute of Sport’s Sports Supplement program provides information on bicarb loading, visit http://www.ausport.gov.au/ais/nutrition
