This study examined the changes in the physiological profile of children engaged in organized sporting activity compared to a group of normally active children. Eight children (mean age 11.4 yrs) from each of four popular sports in Australia (badminton, basketball, netball, and tennis) and an equal number of nontraining children were monitored over a 12-week season. Very few differences occurred between the sporting groups and the control group. No change was reported between groups in peak oxygen uptake at the start and completion of the season. Changes occurring within each group did not consistently reflect any sport-specific characteristics over the season. Flexibility improved significantly, with an average gain of 3.76 cm in all groups except basketball players, who gained only 0.69 cm for the 12 weeks. Anaerobic power demonstrated significant improvement only within those sporting groups whose training specifically included explosive based activity. It is suggested that the active nature of the control children and use of only 12 weeks of data collection could have contributed to the limited physiological differences observed between active sporting and nonsporting children.
Geraldine Naughton and John Carlson
Geraldine Naughton and John Carlson
The heart rate intensity during 20 minutes of sports participation by circumpubertal children was monitored several times over a season. The competitive games’ mean absolute heart rates for basketball, badminton, netball, and tennis were 170, 159, 168, and 162 bts·min−1 (or 72, 75, 69, and 67% of heart rate maximum), respectively. The mean abolute heart rates for 20 minutes of participation under practice conditions for badminton, basketball, netball, and tennis were 149, 157, 144, and 135 bts·min−1, or 73, 75, 69, and 67% of heart rate maximum. At the 0.05 level of probability there was a significant difference between the heart rate intensities under competitive game and practice situations in the badminton, netball, and tennis groups. The difference between intensities of competitive games and practices was nonsignificant in the basketball players. The study concluded that participation in practice and game conditions was positive in providing the potential for a training stimulus.
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.
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.
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.
Sandra luliano, Geraldine Naughton, Greg Collier and John Carlson
Thirty-two elite junior athletes in two age categories, older than or equal to IS years old (O15) (8 females and 9 males) and less than 15 years old (U15) (8 females and 7 males), performed a laboratory-based duathlon (run-ride-run). At the completion of the event, significant body mass losses were recorded for all groups. Compared with the other three groups, the O15 males lost body mass at a greater absolute rate (1.26 ±0.06 kg ⋅ hr−1 vs. a mean of 0.62 ±0.11 kg ⋅ hr−1 for the other three groups) and a greater relative rate (1.95 ± 0.10% BM ⋅ hr−1 vs. a mean of 1.23 ± 0.19 %BM ⋅ hr−1 for the other three groups) (p < .05). No differences were observed between groups for fluid consumption. Subjects consumed more fluid (p < .05) during the cycle phase and postevent than preevenl or during the run phases. Results indicated that the athletes' fluid intake practices were insufficient to maintain adequate hydration during the simulated event.
James P. Veale, Alan J. Pearce and John S. Carlson
The aim of this study was to test the reliability and construct validity of a reactive agility test (RAT), designed for Australian Football (AF).
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).
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.
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.
Eric T. Hyde, John D. Omura, Kathleen B. Watson, Janet E. Fulton and Susan A. Carlson
Background: To estimate the proportion of adults’ and parents’ knowledge of the adult aerobic and youth physical activity guidelines, respectively, in the United States. Methods: Data were analyzed from a national sample of adults in the 2017 ConsumerStyles survey. Prevalence of knowledge of the adult aerobic guideline (ie, 150 min/wk of moderate-intensity activity) was estimated among all respondents (n = 3910) and of the youth guideline (ie, 60 min/d of physical activity on 7 d/wk) among parents (n = 1288). Odds ratios were estimated using logistic regression models adjusting for demographic characteristics. Results: Overall, 2.5% (95% confidence interval, 2.0–3.1) of adults and 23.0% (95% confidence interval, 20.5–25.7) of parents were knowledgeable of the adult aerobic and youth guidelines, respectively. After adjustment, odds of knowledge of the adult guideline differed significantly by sex and physical activity level, whereas knowledge of the youth guideline differed by parental education level. Conclusions: Despite the release of the 2008 Physical Activity Guidelines for Americans nearly a decade ago, most US adults and parents lack knowledge of the adult aerobic and youth physical activity guidelines. Effective communication strategies may help raise awareness of current and future editions of national guidelines for physical activity.
James P. Veale, Alan J. Pearce, David Buttifant and John S. Carlson
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.
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.
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).
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.