This investigation aimed to determine whether the physical work capacity of nonanemic athletes could be improved when plasma ferritin concentrations of below 30 nglml were raised at least 15 ng/ml. The experimental group consisted of 15 training athletes, each of whose plasma ferritin concentration was less than 30 ng/ml (mean and SD of 19.8 ±8.4 nglml). In a control group of 16, each was measured with a plasma ferritin concentration of more than 40 ng/ml (mean and SD of 83.3 ±37.6 ngfml). All participated in submaximal and maximal tests for aerobic and anaerobic power. Following iron supplementation, plasma fenitin concentration in each experimental subject increased by at least 15 nglml to more than 30 ng/ml, to a new mean of 46.3 ±15.5 ng/ml. The performance measures were also repeated, but no significant overall effects were associated with the increased plasma ferritin concentrations. These data provide no sound evidence that physical work capacity of athletes is enhanced when plasma ferritin concentrations of around 20 ng/ml are increased by at least 15 ng/ml.
Richard D. Telford, Christopher J. Bunney, Edward A. Catchpole, Wendy R. Catchpole, Vicki Deakin, Bon Gray, Allan G. Hahn and Deborah A. Kerr
Martin C. Waller, Deborah A. Kerr, Martyn J. Binnie, Emily Eaton, Clare Wood, Terreen Stenvers, Daniel F. Gucciardi, Carmel Goodman and Kagan J. Ducker
The authors aimed to update knowledge of the use of supplements among Australian athletes at a state-based sports institute. The authors conducted a cross-sectional survey using an online questionnaire to assess the influence of age, sports category, and scholarship category on supplement use. Of 94 completed questionnaires, 82 (87%) indicated supplements in the previous 12 months (mean = 4.9 ± 3.3). No significant difference in supplement usage rate was identified when considering age, scholarship category, or sport category. The most frequently used supplements were sports drinks (70%), caffeine (48%), protein powder (42%), and sports bars (42%). Recovery (63%), health maintenance (59%), and improved energy (50%) were the most frequently reported rationale to use supplements. Allied health professionals and credible online resources were the predominant sources of influence regarding use. However, athletes from lower scholarship categories were more likely to have social media, parents, and siblings influence usage, and age was inversely related to increased influence from parents, social media, physicians not associated with the institute, the Internet, and siblings. Older athletes and those on higher scholarships were more likely to source supplements from training facilities and sports nutrition staff outside of the institute or direct from a supplier, whereas those on lower scholarships tended to rely more on family and friends for their supplements. Findings from this study show a high prevalence of supplement use and are the first to show an influence of social media, particularly in younger athletes. Opportunities exist to optimize how athletes are informed regarding supplement use and organizational and supplement policy.