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John S. Carlson and Geraldine A. Naughton

The purpose of this study was to determine the anaerobic capacity of children using the maximal accumulated oxygen deficit technique (AOD). Eighteen healthy children (9 boys, 9 girls) with a mean age of 10.6 years volunteered as subjects. Peak oxygen uptake and submaximal steady-state oxygen uptake tests were conducted against progressive constant work rates on a Cybex cycle ergometer. Supramaximal work rates were predicted from the linear regression of submaximal steady-state work rates and oxygen uptakes to equal 110, 130, and 150% of peak oxygen uptake. Results indicated a significant interaction in the responses of both sexes when the accumulated oxygen deficit data were expressed in both absolute and relative terms. The profile of accumulated oxygen deficits across the three intensities indicated a downward shift in the girls responses between the 110 and 150% supramaximal tests. This trend was not evident in the boys’ responses. Intraclass correlations conducted on test-retest data indicated that compared to the boys, the reliability of the girls in the accumulated oxygen deficits in liters and ml·kg−1 was poorer.

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Geraldine A. Naughton and John S. Carlson

A definitive measure for assessing the energy contribution of anaerobic pathways during exhaustive exercise remains inconclusive. The accumulated oxygen deficit (AOD) has been used in several studies to estimate energy contribution. The underlying assumptions of the AOD measure have been criticized for underestimating the true contribution of anaerobic metabolism in high intensity exercise. Indeed, the AOD measure has been the subject of much controversy. Several of the physiological exercise responses of children may lead to an even greater underestimation of the anaerobic energy contribution to high intensity exercise in children than adults when AOD measures are calculated.

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James P. Veale, Alan J. Pearce and John S. Carlson

Purpose:

The aim of this study was to test the reliability and construct validity of a reactive agility test (RAT), designed for Australian Football (AF).

Methods:

Study I tested the reliability of the RAT, with 20 elite junior AF players (17.44 ± 0.55 y) completing the test on two occasions separated by 1 wk. Study II tested its construct validity by comparing the performance of 60 participants (16.60 ± 0.50 y) spread over three aged-matched population groups: 20 athletes participating in a State Under-18 AF league who had represented their state at national competitions (elite), 20 athletes participating in the same league who had not represented their state (subelite), and 20 healthy males who did not play AF (controls).

Results:

Test-retest reliability reported a strong correlation (0.91), with no significant difference (P = .22) between the mean results (1.74 ± 0.07 s and 1.76 ± 0.07 s) obtained (split 2+3). Nonparametric tests (Kruskal-Wallis and Mann-Whitney) revealed both AF groups performed significantly faster on all measures than the control group (ranging from P = .001 to .005), with significant differences also reported between the two AF groups (ranging from P = .001 to .046). Stepwise discriminant analyses found total time discriminated between the groups, correctly classifying 75% of the participants.

Conclusions:

The RAT used within this study demonstrates evidence of reliability and construct validity. It further suggests the ability of a reactive component within agility test designs to discriminate among athletes of different competition levels, highlighting its importance within training activities.

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David C. Buttifant, John S. Carlson and Geraldine A. Naughton

Anaerobic characteristics of preadolescent asthmatic and nonasthmatic males were measured using the accumulated oxygen deficit (AOD) on 10 asthmatics (mean age = 10.9 years) and 10 nonasthmatics (mean age = 11.1 years). Subjects ran to exhaustion at speeds that were 110% and 130% of their V̇O2 peak. Mean AOD values for 110% and 130% were 53.23 ± 4.02 and 50.60 ± 2. 81 ml · kg−1, respectively, for the asthmatic children’s and 51.59 ± 2.66 and 47.04 ± 3.44 ml · kg−1, respectively, for the nonasthmatic children. There were no statistically significant differences in anaerobic characteristics measured by AOD values (p > .05) between intensities and groups. FEV1 data revealed that there was no bronchoconstriction occurring in either group under either of the test intensity conditions for up to 15 min postexercise.

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James P. Veale, Alan J. Pearce, David Buttifant and John S. Carlson

Purpose:

Body structure and physical development must be addressed when preparing junior athletes for their first season in a senior competition. The aim of this preliminary study was to measure the extent of the assumption that final year junior Australian Football (AF) athletes are at a physical mismatch to their senior counterparts.

Methods:

Twenty-one male participants (17.71 ± 0.27 y) were recruited from one state based elite junior AF competition and forty-one male participants (22.80 ± 4.24 y) were recruited from one club competing in the senior elite Australian Football League (AFL), who were subsequently divided into two groups; professional rookies aged 18-20 y (19.44 ± 0.70 y; n = 18) and professional seniors aged 21+ y (25.43 ± 3.98 y; n = 23). Dual energy X-ray absorptiometry (DEXA) scans of all participants were completed.

Results:

Despite being an average 6.0% and 6.1% lighter in total weight and lean mass respectively, no significant difference was found between the elite junior athletes and their professional AFL rookie counterparts. However, significant differences were demonstrated in comparison with the professional AFL senior athletes (P < .01). Both professional AFL groups demonstrated greater than 0.3 kg total bone mineral content (BMC) than the elite junior athletes (P < .01) and significantly greater segmental BMC and bone mineral density (BMD) results (P < .05).

Conclusion:

While the results identify the differences in body composition of the elite junior athletes, development in a linear fashion is noted, providing useful information for the creation of age appropriate expectations and training programs.