The effects of sodium bicarbonate ingestion on swimming interval performance in trained competitive swimmers.

The use of sodium bicarbonate (NaHCO3) supplementation to improve repeated high-intensity performance is recommended; however, most swimming performance studies examine time trial efforts rather than repeated swims with interspersed recovery that are more indicative of training sessions. The aim of this study, therefore, was to investigate the effects of 0.3 g.kg-1 BM NaHCO3 supplementation on sprint interval swimming (8 × 50 m) in regionally trained swimmers. Fourteen regionally competitive male swimmers (body mass (BM): 73 ± 8 kg) volunteered for this double-blind, randomised, crossover designed study. Each participant was asked to swim 8 × 50 m (front crawl) at a maximum intensity from a diving block, interspersed with 50 m active recovery swimming. After one familiarisation trial, this was repeated on two separate occasions whereby participants ingested either 0.3 g.kg-1 BM NaHCO3 or 0.05 g.kg-1 BM sodium chloride (placebo) in solution 60 min prior to exercise. Whilst there were no differences in time to complete between sprints 1-4 (p > 0.05), improvements were observed in sprint 5 (p = 0.011; ES = 0.26), 6 (p = 0.014; ES = 0.39), 7 (p = 0.005; ES = 0.60), and 8 (p = 0.004; ES = 0.79). Following NaHCO3 supplementation, pH was greater at 60 min (p < 0.001; ES = 3.09), whilst HCO3- was greater at 60 min (p < 0.001; ES = 3.23) and post-exercise (p = 0.016; ES = 0.53) compared to placebo. These findings suggest NaHCO3 supplementation can improve the latter stages of sprint interval swimming performance, which is likely due to the augmentation of pH and HCO3- prior to exercise and the subsequent increase in buffering capacity during exercise.

A randomised controlled trial of the outcome of health assessment of people aged 75 years and over.

OBJECTIVES: To measure the outcomes of a health assessment, conducted by a nurse, of people aged 75 years and older (75+HA) living independently in their own homes. DESIGN: Randomised controlled trial (RCT). SETTING: A convenience sample of six general practices within the Adelaide Western Division of General Practice (AWDGP). A random sample of 100 participants was drawn from practice age-sex registers. Data were collected in initial visits between 1 August 1998 and February 1999, then in follow-up visits one year later. PARTICIPANTS: Participants were aged 75 years and over on 1 August 1998 and living independently in the community. 145 eligible patients were invited to join the study, and 100 of these consented to enrol (69%). INTERVENTION: A 75+HA conducted in the participant's home by a nurse and reported to their usual general practitioner. MAIN OUTCOME MEASURES: Primary: number of problems in each group; number of participants with problems; and mortality. Secondary: physical function; psychological (including cognitive) function; falls; and admission to institution. RESULTS: There were no significant differences between the control and intervention groups at follow-up in the number of problems, the number of participants with problems, or mortality. In the intervention group, there was significant improvement in self-rated health, geriatric depression score (GDS 15), and number of falls. CONCLUSIONS: This RCT has not demonstrated improvement in health status of the intervention group which received a 75+HA compared with a control group left to usual care.