mSRT scores on over a million children aged from 9 to 17 years have been used to estimate peak V ˙ O 2 and collate values ratio-scaled with body mass into international aerobic fitness “norms” ( 21 ); and inter-country comparisons of “who are the fittest?” based on peak V ˙ O 2 predicted from 20
Grant R. Tomkinson, Justin J. Lang, Joel Blanchard, Luc A. Léger and Mark S. Tremblay
. References 1. Adegboye AR , Anderssen SA , Froberg K , et al . Recommended aerobic fitness level for metabolic health in children and adolescents: a study of diagnostic accuracy . Br J Sports Med . 2011 ; 45 ( 9 ): 722 – 8 . PubMed ID: 20558527 doi:10.1136/bjsm.2009.068346 20558527 10.1136/bjsm
Han C.G. Kemper, Jos W.R. Twisk and Willem van Mechelen
In the Amsterdam Growth And Health Longitudinal Study (AGAHLS), a group of approximately 650 12- to 14-year-old boys and girls was followed in their growth, and development of their health their lifestyle including diet, physical activity and smoking. One of the main interests was the change in their aerobic fitness. From 12 to 36 years of age in total, eight repeated measurements were performed to measure peak oxygen uptake (peak VO2). In this study the data of peak VO2 are revisited and extended: We made use of all collected data as a mixed longitudinal design including cross-sectionally measured subjects as well as longitudinally measured subjects. This led to the availability of 1,194 boys and 1356 girls. With generalized estimating equations (GEE) the longitudinal changes with chronological age and differences between boys and girls were analyzed. Teenage boys and girls increased their peak VO2 (ml/min) significantly (p < .001) until age 14 in girls and until age 17 in boys. However peak VO2 relative to bodyweight (peak VO2/BW) had significantly (p < .001) decreased over the whole age range from 12 to 36 in both sexes. Vigorous physical activity (VPA) also showed a decrease and was significantly (p < .001) related with lower peak VO2/BW (Beta = 0.001). This relation was stronger in boys than in girls. Because at the start of AGAHLS no fast responding metabolic instruments were available, future longitudinal studies about aerobic fitness should include also measurement of VO2 kinetics.
Maxwell Ruby, Chris P. Repka and Paul J. Arciero
Yoga/Stretching (YS) and functional resistance (FR) training are popular exercise routines. A protein-pacing (PP) diet is a common dietary regimen. Thus, we assessed the effectiveness of a PP diet alone and in combination with either YS or FR to improve body composition and cardiometabolic health.
Twenty-seven overweight women (age = 43.2 ± 4.6 years) were randomized into 3 groups: yoga (YS, n = 8) or resistance (FR, n = 10) training (3 days/week) in conjunction with PP diet (50% carbohydrate, 25% protein, and 25% fat) or PP diet-only (PP, n = 9) throughout 12-week study. PP maintained preexisting levels of physical activity. Body weight (BW), total (BF) and abdominal (ABF) body fat, waist circumference (WC), plasma biomarkers, and aerobic fitness (VO2) were measured at baseline and 12 weeks.
WC and total cholesterol improved in all groups, whereas glycemia tended to improve (P = .06) in S. BF, ABF, and VO2 increased significantly in YS and FR (P < .05). Feelings of vigor increased in YS and tension decreased in FR (P < .05).
YS training tended to decrease blood glucose compared with FR and PP and is equally effective at enhancing body composition, and aerobic fitness in overweight women providing a strong rationale for further research on YS training.
Shane Malone, Mark Roe, Dominic A. Doran, Tim J. Gabbett and Kieran D. Collins
To examine the association between combined session rating of perceived exertion (RPE) workload measures and injury risk in elite Gaelic footballers.
Thirty-seven elite Gaelic footballers (mean ± SD age 24.2 ± 2.9 y) from 1 elite squad were involved in a single-season study. Weekly workload (session RPE multiplied by duration) and all time-loss injuries (including subsequent-wk injuries) were recorded during the period. Rolling weekly sums and wk-to-wk changes in workload were measured, enabling the calculation of the acute:chronic workload ratio by dividing acute workload (ie, 1-weekly workload) by chronic workload (ie, rolling-average 4-weekly workload). Workload measures were then modeled against data for all injuries sustained using a logistic-regression model. Odds ratios (ORs) were reported against a reference group.
High 1-weekly workloads (≥2770 arbitrary units [AU], OR = 1.63–6.75) were associated with significantly higher risk of injury than in a low-training-load reference group (<1250 AU). When exposed to spikes in workload (acute:chronic workload ratio >1.5), players with 1 y experience had a higher risk of injury (OR = 2.22) and players with 2–3 (OR = 0.20) and 4–6 y (OR = 0.24) of experience had a lower risk of injury. Players with poorer aerobic fitness (estimated from a 1-km time trial) had a higher injury risk than those with higher aerobic fitness (OR = 1.50–2.50). An acute:chronic workload ratio of (≥2.0) demonstrated the greatest risk of injury.
These findings highlight an increased risk of injury for elite Gaelic football players with high (>2.0) acute:chronic workload ratios and high weekly workloads. A high aerobic capacity and playing experience appears to offer injury protection against rapid changes in workload and high acute:chronic workload ratios. Moderate workloads, coupled with moderate to high changes in the acute:chronic workload ratio, appear to be protective for Gaelic football players.
Han C.G. Kemper and Lando L.J. Koppes
The purpose of this study was to test the hypothesis that physical activity (PA), measured over a period of 23 years, is beneficial to aerobic fitness (VO2max) in boys and girls (13-36 years) who were enrolled in the Amsterdam Growth and Health Longitudinal Study (AGAHLS). PA was measured using a standardized activity interview. VO2max was assessed directly with a maximal running test on a treadmill. To assess the longitudinal relationship between PA and VO2max, different longitudinal analyses were carried out over different age periods, correcting for various confounders such as lifestyle parameters, biological parameters, and initial VO2max. Highly significant relationships (p < .05) were observed between PA and VO2max in four of the five analyses. However, in an autoregression analysis, when current PA has been related to the future change in VO2max, the results are not any more significant (p > .05). Analysis of the data of PA and VO2max from the AGAHLS population does not fully support the hypothesis that PA affects VO2max.
Neil Armstrong and Jo Welsman
Aerobic fitness defines the ability to deliver oxygen to the muscles and to use it to generate energy to support muscle activity during exercise. Peak oxygen uptake ( V ˙ O 2 ), the highest V ˙ O 2 achieved during an incremental exercise test to exhaustion, is internationally recognized as the
The presence of a maturational threshold that modulates children’s physiological responses to exercise training continues to be debated, not least due to a lack of longitudinal evidence to address the question. The purpose of this study was to investigate the interaction between swim-training status and maturity in nineteen trained (T, 10 ± 1 years, −2.4 ± 1.9 years prepeak height velocity, 8 boys) and fifteen untrained (UT, 10 ± 1 years, −2.3 ± 0.9 years prepeak height velocity, 5 boys) children, at three annual measurements.
In addition to pulmonary gas exchange measurements, stroke volume (SV) and cardiac output (Q) were estimated by thoracic bioelectrical impedance during incremental ramp exercise.
At baseline and both subsequent measurement points, trained children had significantly (p < .05) higher peak oxygen uptake (year1 T 1.75 ± 0.34 vs. UT 1.49 ± 0.22; year 2 T 2.01 ± 0.31 vs. UT 1.65 ± 0.08; year 3 T 2.07 ± 0.30 vs. UT 1.77 ± 0.16 l min−1) and Q (year 1 T 15.0 ± 2.9 vs. UT 13.2 ± 2.2; year 2 T 16.1 ± 2.8 vs. UT 13.8 ± 2.9; year 3 T 19.3 ± 4.4 vs. UT 16.0 ± 2.7 l min−1). Furthermore, the SV response pattern differed significantly with training status, demonstrating the conventional plateau in UT but a progressive increase in T. Multilevel modeling revealed that none of the measured pulmonary or cardiovascular parameters interacted with maturational status, and the magnitude of the difference between T and UT was similar, irrespective of maturational status.
The results of this novel longitudinal study challenge the notion that differences in training status in young people are only evident once a maturational threshold has been exceeded.
Jannique G.Z. van Uffelen, Marijke J.M. Chinapaw, Marijke Hopman-Rock and Willem van Mechelen
This study examined the feasibility and effect on aerobic fitness of a 1-yr, twice-weekly, group-based moderate-intensity walking program (MI-WP, n = 77) compared with a low-intensity activity program (LI-AP, n = 75) for community-dwelling older adults with mild cognitive impairment (MCI). Thirty participants did not start a program; median attendance in the other 122 participants was 71%. Small but significant associations were observed between attendance and memory in the MI-WP and general cognition in the LI-AP. Associations were no longer significant when both groups were analyzed together. Intensity, assessed using percentage of heart-rate reserve and the Borg scale, equaled intended intensity for both programs. Aerobic fitness improved significantly in participants in the MI-WP. In conclusion, cognition was not clearly associated with attendance in the 62 participants starting the MI-WP, and average attendance was good. The intensity was feasible for participants who continued the MI-WP. The findings support the proposal that regular moderate-intensity walking improves aerobic fitness in adults with MCI.
Non-Eleri Thomas, Stephen-Mark Cooper, Simon P. Williams, Julien S. Baker and Bruce Davies
The purpose of this study was to examine relationships between aerobic fitness (AF), fatness, and coronary-heart-disease (CHD) risk factors in 12- to 13-year-olds. The data were obtained from 208 schoolchildren (100 boys; 108 girls) ages 12.9 ± 0.3 years. Measurements included AF, indices of obesity, blood pressure, blood lipids and lipoproteins, fibrinogen, homocysteine, and C-reactive protein. An inverse relationship was found between AF and fatness (p < .05). Fatness was related to a greater number of CHD risk factors than fitness was (p < .05). Further analysis revealed fatness to be an independent predictor of triglyceride and blood-pressure levels (p < .05). Our findings indicate that, for young people, fatness rather than fitness is independently related to CHD risk factors.