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  • Author: Allan G. Hahn x
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Richard D. Telford, Edward A. Catchpole, Vicki Deakin, Allan G. Hahn and Ashley W. Plank

The effect of vitamin and mineral supplementation was studied over 7 to 8 months of training and competition in 82 athletes from four sports: basketball, gymnastics, rowing, and swimming. Matched subgroups were formed and a double-blind design used, with subgroups being given either the supplementation or a placebo. All athletes were monitored to ensure that the recommended daily intakes (RDI) of vitamins and minerals were provided by diet alone. Sport-specific and some common tests of strength as well as aerobic and anaerobic fitness were performed. Coaches' assessment of improvement was also obtained. The only significant effect of supplementation was observed in the female basketball players, in which the supplementation was associated with increased body weight, skinfold sum, and jumping ability. A significant increase in skinfold sum was also demonstrated over the whole group as a result of supplementation. In general, however, this study provided little evidence of any effect of supplementation to athletic performance for athletes consuming the dietary RDIs.

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Michael J. Ashenden, David T. Martin, Geoffrey P. Dobson, Colin Mackintosh and Allan G. Hahn

The aim of this study was to establish whether extremely low serum ferritin values in female athletes were associated with indications of iron deficiency anemia and whether serum ferritin values were influenced by the type of training or participants' body size. Hematological data collected during 6 years at the Australian Institute of Sport were reviewed to quantify changes in serum ferritin concentration associated with training and to establish whether decrements in serum ferritin were associated with any change in hemoglobin concentration, mean corpuscular volume, or mean corpuscular hemoglobin concentration. Mean serum ferritin concentrations of 7.5 μg ⋅ L−1 were not associated with any indication of iron-deficiency anemia. Serum ferritin declined by approximately 25% with the onset of rigorous daily training (p <.01) whether training was predominantly weight-bearing or non-weight-bearing. Rowers had significantly higher ferritin concentrations than basketball players of similar stature (p = .02). We conclude that considerable background information such as the stage of training, specific sport, and previous blood results should be sought when interpreting serum ferritin concentrations in female athletes.

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Gary J. Slater, Anthony J. Rice, David Jenkins, Jason Gulbin and Allan G. Hahn

To strengthen the depth of lightweight rowing talent, we sought to identify experienced heavyweight rowers who possessed physique traits that predisposed them to excellence as a lightweight. Identified athletes (n = 3) were monitored over 16 wk. Variables measured included performance, anthropometric indices, and selected biochemical and metabolic parameters. All athletes decreased their body mass (range 2.0 to 8.0 kg), with muscle mass accounting for a large proportion of this (31.7 to 84.6%). Two athletes were able to maintain their performance despite reductions in body mass. However, performance was compromised for the athlete who experienced the greatest weight loss. In summary, smaller heavyweight rowers can successfully make the transition into the lightweight category, being nationally competitive in their first season as a lightweight.

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Gary Slater, David Jenkins, Peter Logan, Hamilton Lee, Matthew Vukovich, John A. Rathmacher and Allan G. Hahn

This investigation evaluated the effects of oral β-Hydroxy-β-Methylbutyrate (HMB) supplementation on training responses in resistance-trained male athletes who were randomly administered HMB in standard encapsulation (SH), HMB in time release capsule (TRH), or placebo (P) in a double-blind fashion. Subjects ingested 3 g · day−1 of HMB or placebo for 6 weeks. Tests were conducted pre-supplementation and following 3 and 6 weeks of supplementation. The testing battery assessed body mass, body composition (using dual energy x-ray absorptiometry), and 3-repetition maximum isoinertial strength, plus biochemical parameters, including markers of muscle damage and muscle protein turnover. While the training and dietary intervention of the investigation resulted in significant strength gains (p < .001) and an increase in total lean mass (p = .01), HMB administration had no influence on these variables. Likewise, biochemical markers of muscle protein turnover and muscle damage were also unaffected by HMB supplementation. The data indicate that 6 weeks of HMB supplementation in either SH or TRH form does not influence changes in strength and body composition in response to resistance training in strength-trained athletes.

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Philo U. Saunders, Richard D. Telford, David B. Pyne, Christopher J. Gore and Allan G. Hahn

We quantified the effect of an extended live high-train low (LHTL) simulated altitude exposure followed by a series of training camps at natural moderate altitude on competitive performance in seven elite middle-distance runners (Vo2max 71.4 ± 3.4 mL·min−1·kg−1, mean ± SD). Runners spent 44 ± 7 nights (mean ± SD) at a simulated altitude of 2846 ± 32 m, and a further 4 X 7- to 10-d training at natural moderate altitude (1700–2200 m) before racing. The combination of simulated LHTL and natural altitude training improved competitive performance by 1.9% (90% confidence limits, 1.3-2.5%). Middle-distance runners can confidently use a combination of simulated and natural altitude to stimulate adaptations responsible for improving performance.

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Richard D. Telford, Christopher J. Bunney, Edward A. Catchpole, Wendy R. Catchpole, Vicki Deakin, Bon Gray, Allan G. Hahn and Deborah A. Kerr

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.