Harry E. Routledge, Stuart Graham, Rocco Di Michele, Darren Burgess, Robert M. Erskine, Graeme L. Close and James P. Morton
The authors aimed to quantify (a) the periodization of physical loading and daily carbohydrate (CHO) intake across an in-season weekly microcycle of Australian Football and (b) the quantity and source of CHO consumed during game play and training. Physical loading (via global positioning system technology) and daily CHO intake (via a combination of 24-hr recall, food diaries, and remote food photographic method) were assessed in 42 professional male players during two weekly microcycles comprising a home and away fixture. The players also reported the source and quantity of CHO consumed during all games (n = 22 games) and on the training session completed 4 days before each game (n = 22 sessions). The total distance was greater (p < .05) on game day (GD; 13 km) versus all training days. The total distance differed between training days, where GD-2 (8 km) was higher than GD-1, GD-3, and GD-4 (3.5, 0, and 7 km, respectively). The daily CHO intake was also different between training days, with reported intakes of 1.8, 1.4, 2.5, and 4.5 g/kg body mass on GD-4, GD-3, GD-2, and GD-1, respectively. The CHO intake was greater (p < .05) during games (59 ± 19 g) compared with training (1 ± 1 g), where in the former, 75% of the CHO consumed was from fluids as opposed to gels. Although the data suggest that Australian Football players practice elements of CHO periodization, the low absolute CHO intakes likely represent considerable underreporting in this population. Even when accounting for potential underreporting, the data also suggest Australian Football players underconsume CHO in relation to the physical demands of training and competition.
Ricardo J.S. Costa, Vera Camões-Costa, Rhiannon M.J. Snipe, David Dixon, Isabella Russo and Zoya Huschtscha
The study aimed to determine the impact of a dairy milk recovery beverage immediately after endurance exercise on leukocyte trafficking, neutrophil function, and gastrointestinal tolerance markers during recovery. Male runners (N = 11) completed two feeding trials in randomized order, after 2 hr of running at 70%
Amelia J. Carr, Philo U. Saunders, Laura A. Garvican-Lewis and Brent S. Vallance
Purpose: To quantify, for an elite-level racewalker, altitude training, heat acclimation and acclimatization, physiological data, and race performance from January 2007 to August 2008. Methods: The participant performed 7 blocks of altitude training: 2 “live high:train high” blocks at 1380 m (total = 22 d) and 5 simulated “live high:train low” blocks at 3000 m/600 m (total = 98 d). Prior to the 2007 World Championships and the 2008 Olympic Games, 2 heat-acclimation blocks of ~6 weeks were performed (1 session/week), with ∼2 weeks of heat acclimatization completed immediately prior to each 20-km event. Results: During the observation period, physiological testing included maximal oxygen uptake (VO2max, mL·kg−1·min−1), walking speed (km·h−1) at 4 mmol·L−1 blood lactate concentration [La−], body mass (kg), and hemoglobin mass (g), and 12 × 20-km races and 2 × 50-km races were performed. The highest VO2max was 67.0 mL·kg−1·min−1 (August 2007), which improved 3.1% from the first measurement (64.9 mL·kg−1·min−1, June 2007). The highest percentage change in any physiological variable was 7.1%, for 4 mmol·L−1 [La−] walking speed, improving from 14.1 (June 2007) to 15.1 km·h−1 (August 2007). Personal-best times for 20 km improved from (hh:mm:ss) 1:21:36 to 1:19:41 (2.4%) and from 3:55:08 to 3:39:27 (7.1%) in the 50-km event. The participant won Olympic bronze and silver medals in the 20- and 50-km, respectively. Conclusions: Elite racewalkers who regularly perform altitude training may benefit from periodized heat acclimation and acclimatization prior to major international competitions in the heat.
Joseph O.C. Coyne, Sophia Nimphius, Robert U. Newton and G. Gregory Haff
Lorenzo Lolli, Alan M. Batterham, Gregory MacMillan, Warren Gregson and Greg Atkinson
Jos J. de Koning
Rachel McCormick, Brian Dawson, Marc Sim, Leanne Lester, Carmel Goodman and Peter Peeling
The authors compared the effectiveness of two modes of daily iron supplementation in athletes with suboptimal iron stores: oral iron (PILL) versus transdermal iron (PATCH). Endurance-trained runners (nine males and 20 females), with serum ferritin concentrations <50 μg/L, supplemented with oral iron or iron patches for 8 weeks, in a parallel group study design. Serum ferritin was measured at baseline and fortnightly intervals. Hemoglobin mass and maximal oxygen consumption (