performed during the match. 9 However, it is not known whether this relationship holds for the 2-km time trial or final velocity during the 30:15 IFT . Moreover, although a previous study in rugby sevens has shown that players at higher levels have greater aerobic fitness, 10 it is not yet known if higher
Mitchell J. Henderson, Job Fransen, Jed J. McGrath, Simon K. Harries, Nick Poulos and Aaron J. Coutts
Daniel Bok and Igor Jukić
mostly responsible for inducing muscle damage. Studies also show that prematch values can be influenced by a player’s aerobic fitness, 10 whereas postmatch values can be influenced by lower-limb strength. 11 Aerobically less fit Australian rules football players present higher prematch [CK], even with
Niall Casserly, Ross Neville, Massimiliano Ditroilo and Adam Grainger
typically possess greater body mass than backs, owing to their role of gaining and retaining possession, whereas backs typically attempt to avoid contact and, therefore, require greater speed and evasion qualities and greater levels of aerobic fitness. 17 These differences are important to consider when
Kenneth H. Pitetti, Daniel A. Yarmer and Bo Fernhall
The purpose of this study was to compare the aerobic fitness and body mass index (BMI) of children and adolescents (8-18 yr) with and without mild mental retardation (MR). Sample size of participants with MR but without Down syndrome was 169 males and 99 females. Sample size of participants without MR was 289 males and 317 females. Analysis was made by gender and age: children (8-10 yr); early adolescents (11-14 yr); and late adolescents (15-18 yr). The 20-m shuttle run test (20 MST) was used to assess field test performance and predicted aerobic fitness. For all age groups, females and males without MR ran significantly more laps and had a significantly higher predicted aerobic fitness (V̇O2peak: ml $$ kg-1 $$ min-1) than their peers with MR. Additionally, participants with MR tended to have higher BMI than their peers without MR. The results of this study indicate that children and adolescents with MR have lower exercise capacity, lower aerobic fitness, and higher BMIs than their peers without MR.
Peter A. Hosick, Robert G. McMurray and Dan M. Cooper
The relationship between peak aerobic fitness (peakVO2) and plasma leptin was assessed in 25 normal (BMI < 85th %tile) and 25 overweight (BMI > 85th %tile) youth, ages 7–17 years. In the overall analysis peakVO2 was related to leptin when expressed in mL/kg/min (R 2 = .516, p < .0001), or as ml/kgFFM/min (R 2 = .127, p = .01). The relationships between peakVO2 and leptin were no longer significant when percent bodyfat was added to the models. In subanalyses by weight groups, peakVO2: leptin relationships were not evident for normal weight, but remained for overweight youth. In conclusion the relationship between aerobic fitness and leptin in youth is dependent upon weight status.
Andrea Di Blasio, Pascal Izzicupo, Emanuele D’Angelo, Sandra Melanzi, Ines Bucci, Sabina Gallina, Angela Di Baldassarre and Giorgio Napolitano
High-intensity aerobic interval training (AIT) has been reported to be more effective than continuous aerobic training (CoAT) to improve metabolic health. The aim of our study was to investigate whether moderate-intensity AIT is more effective than CoAT on metabolic health when applied to a walking training program.
Thirty-two postmenopausal women (55.37 ± 3.46 years) were investigated for body composition, plasma glucose, insulin, lipids, adiponectin, HOMA-IR, HOMA-AD, aerobic fitness, dietary habits, and spontaneous physical activity, and randomly assigned to one of two different walking training programs: CoAT or AIT.
CoAT and AIT elicited the same physiological benefits, including: reduction of plasma glucose, insulin, HOMA-IR and HOMA-AD, and increase of plasma HDL-C, adiponectin, and aerobic fitness.
An AIT scheme as part of an outdoor walking training program elicits the same physiological adaptations as a CoAT scheme, probably because walking does not promote exercise intensities that elicit greater effects.
Iñigo Mujika, Juanma Santisteban, Paco Angulo and Sabino Padilla
A 7-week, 10-session individual training program was implemented with a youth elite football (soccer) player who had been underperforming because of poor aerobic fitness. The intervention focused on developing aerobic power and high lactate production and contributed to a 32.3% improvement in a football-specific performance test. The player was able to return to play and exceed expected performance levels during competitive match play.
Bumsoo Ahn, Robert McMurray and Joanne Harrell
The relationship between insulin resistance (HOMA-IR), percent body fat, and aerobic fitness (VO2max per unit fat free mass; mL/kgFFM/min) was examined in 1,710 children. Percent body fat was estimated from sum of skinfolds, and VO2max was estimated from submaximal cycle ergometer tests. Overnight fasting blood samples were obtained. VO2max (mL/kgFFM/min) and percent body fat were correlated with HOMA-IR (r=-0.076, p < .002; r=.420, p < .001, respectively); as was VO2max in units of mL/kg/min (r=-0.264, p < .001). When VO2max in mL/kg/min was used, a progressive increase in HOMA-IR was found with decreasing fitness (p < .05). However, when mL/kgFFM/min was used, HOMA-IR scores remained similar between moderate-fit and low-fit group. The stronger association between aerobic fitness (mL/kg/min) and HOMA-IR is partially due to the significant association of fat mass to HOMA-IR. Therefore, our recommendation is to express aerobic fitness in units of mL/kgFFM/min to eliminate the confounding factor of adiposity and better understand the influence of muscle on insulin resistance.
Julian D. Pillay, Tracy L. Kolbe-Alexander, Karin I. Proper, Willem van Mechelen and Estelle V. Lambert
Brisk walking is recommended as a form of health-enhancing physical activity. This study determines the steps/minute rate corresponding to self-paced brisk walking (SPBW); a predicted steps/minute rate for moderate physical activity (MPA) and a comparison of the 2 findings.
A convenience sample (N = 58: 34 men, 24 women, 31.7 ± 7.7yrs), wearing pedometers and a heart rate (HR) monitor, performed SPBW for 10 minutes and 5 indoor sessions, regulated by a metronome (ranging from 60–120 steps/minute). Using steps/minute and HR data of the trials, a steps/minute rate for MPA was predicted. Adjustments were subsequently made for aerobic fitness (using maximal oxygen uptake (VO2max) estimates), age, and sex as possible contributors to stepping rate differences.
Average steps/minute rate for SPBW was 118 ± 9 (116 ± 9; 121 ± 8 for men/women, respectively; P = .022); predicted steps/minute rate for MPA was 122 ± 37 (127 ± 36; 116 ± 39 for men/women, respectively; P < .99) and was similar to steps/minute rate of SPBW (P = .452), even after adjusting for age, sex, and aerobic fitness.
Steps/minute rates of SPBW correlates closely with targeted HR for MPA, independent of aerobic fitness; predicted steps/minute rate for MPA relates closely to steps/minute rates of SPBW. Findings support current PA messages that use the term brisk walking as a reference for MPA.
Trynke Hoekstra, Colin A. Boreham, Liam J. Murray and Jos W.R. Twisk
It is not clear what the relative contribution is of specific components of physical fitness (aerobic and muscular) to cardiovascular disease (CVD) risk. We investigated associations between aerobic fitness (endurance) and muscular fitness (power) and CVD risk factors.
Data were obtained from the Young Hearts project, a representative sample of 12- and 15-year-old boys and girls from Northern Ireland (N = 2016). Aerobic fitness was determined by the 20-m shuttle run test, muscular fitness by the Sargent jump test. CVD risk factors included sum of skinfolds, systolic and diastolic blood pressure, serum total cholesterol (TC), HDL cholesterol, and TC:HDL ratio. Several linear regression analyses were conducted for 4 age and gender groups separately, with the risk factor as the outcome variable.
Significant associations between aerobic fitness and a healthy CVD risk profile were found. These observed relationships were independent of power, whereas the (few) relationships between muscular fitness and the risk factors were partly explained by endurance.
Tailored, preventive strategies during adolescence, incorporating endurance rather than power sports, could be encouraged to help prevent CVD. This is important because existing studies propose that healthiness during adulthood is founded on healthiness in adolescence.