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Michelle S.M. Silva, Wladimir Bolani, Cleber R. Alves, Diogo G. Biagi, José R. Lemos Jr, Jeferson L. da Silva, Patrícia A. de Oliveira, Guilherme B. Alves, Edilamar M. de Oliveira, Carlos E. Negrão, José E. Krieger, Rodrigo G. Dias and Alexandre C. Pereira

Aim:

To study the relationship between the ACTN3 R577X polymorphism and oxygen uptake (VO2) before and after exercise training.

Methods:

Police recruits (N = 206, 25 ± 4 y) with RR (n = 75), RX (n = 97), and XX (n = 33) genotypes were selected. After baseline measures, they underwent 18 wk of running endurance training. Peak VO2 was obtained by cardiopulmonary exercise testing.

Results:

Baseline body weight was not different among genotypes. At baseline, XX individuals displayed higher VO2 at anaerobic threshold, respiratory compensation point, and exercise peak than did RR individuals (P < .003). Endurance training significantly increased VO2 at anaerobic threshold, respiratory compensation point, and exercise peak (P < 2 × 10−6), but the differences between XX and RR were no longer observed. Only relative peak VO2 exercise remained higher in XX than in RR genotype (P = .04). In contrast, the increase in relative peak VO2 was greater in RR than in XX individuals (12% vs 6%; P = .02).

Conclusion:

ACTN3 R577X polymorphism is associated with VO2. XX individuals have greater aerobic capacity. Endurance training eliminates differences in peak VO2 between XX and RR individuals. These findings suggest a ceiling-effect phenomenon, and, perhaps, trained individuals may not constitute an adequate population to explain associations between phenotypic variability and gene variations.

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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.

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Kim Beals, Katherine A. Perlsweig, John E. Haubenstriker, Mita Lovalekar, Chris P. Beck, Darcie L. Yount, Matthew E. Darnell, Katelyn Allison and Bradley C. Nindl

Participants A total of 10 male SQT students volunteered to participate in laboratory testing and observation during MWCW training (age = 23.3 ± 1.8 years, height = 182.3 ± 6.4 cm, weight = 83.6 ± 4.5 kg, body fat = 12.5% ± 3.4%, VO 2 max = 60.0 ± 6.8 ml·kg −1 ·min −1 , and heart rate (HR) max = 190.4 ± 8

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Thomas J. O’Connor, Rick N. Robertson and Rory A. Cooper

Three-dimensional kinematic variables and their relationship to the physiology of racing wheelchair propulsion were studied. Six male wheelchair athletes performed two trials (medium and maximum speed) of 3 min each. VO2, VO2/kg, VE, and HR were measured. Results showed that at medium speed, wrist velocity on hand contact was significantly correlated with VO2/kg. At maximum speed, elbow velocity during preparatory phase was significantly correlated with VO2. Stepwise regression showed wrist trajectory angle and elbow velocity during preparatory phase were significantly correlated with VO2/kg. Results indicate that kinematic variables recorded prior to and on hand contact with the pushrim are significant variables in developing a more efficient racing wheelchair propulsion technique. Results of this study indicate a need to educate coaches of wheelchair track athletes concerning the best racing wheelchair propulsion technique.

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Karin M. Allor and James M. Pivarnik

We calculated individual heart rate–oxygen consumption (HR–V̇O2) regression lines for 49 sixth-grade girls based on a treadmill test. From these data, we determined V̇O2 at HRs of 140 and 160 b · min−1 and 50%, 60%, and 75% of maximal heart rate reserve (MHRR), and the relationship between V̇O2 and %fat at given heart rates. Results indicated traditional 140 and 160 b · min−1 HR cutpoints were at the low end of exercise intensity (46 and 63% V̇O2max) and were negatively correlated with %fat. Heart rates at 50%, 60%, and 75% MHRR corresponded to 52%, 62%, and 76% of V̇O2max. Although the best method for analyzing HR data to describe physical activity intensity is unknown, use of 140 and 160 cutpoints may not describe vigorous or very hard exercise in adolescent girls as well as 75% MHRR. Researchers should also consider the effects of adiposity when using specific heart rate cutpoints.

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Martin Švehlík, Kryštof Slabý, Tomáš Trc̆ and Jir̆í Radvanský

The aim of the study is to investigate whether the net nondimensional oxygen utilization scheme is able to detect postoperative improvement in the energy cost of walking in children with cerebral palsy and to compare it with a body mass normalization scheme. We evaluated 10 children with spastic cerebral palsy before and 9 months after equinus deformity surgery. Participants walked at a given speed of 2 km/hr and 3 km/hr on a treadmill. Oxygen utilization was measured, and mass relative VO2 and net nondimensional VO2 were calculated. Coefficient of variation was used for the description of variability among subjects. Postoperatively, gait kinematics normalized and the mass relative VO2 and net nondimensional VO2 showed significant improvement. Net nondimensional VO2 is able to detect postoperative improvement with smaller variability among subjects than body mass related normalization in children with cerebral palsy.

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Neil Armstrong, Joanne Williams, John Balding, Peter Gentle and Brian Kirby

The peak oxygen uptake (VO2) of 199 boys and 164 girls (mean age 13.2±1.3 yrs) was examined in relation to their body fatness, blood pressure, and serum cholesterol level. Peak VO2 was significantly correlated with skinfold thickness in both sexes (range r = −0.41 to −0.56). When the common effects of skinfold thickness were removed, no significant relationships were observed between peak VO2 and either serum cholesterol or blood pressure. The habitual physical activity (HPA) of 92 boys and 132 girls (mean age 13.0+1.3 yrs) was examined in relation to their body fatness, blood pressure, and serum cholesterol. No significant relationships were observed. The results of this study indicate that although skinfold thickness is negatively related to peak VO2, favorable relationships between children’s peak VO2 or HPA and either blood pressure or serum cholesterol remain to be proven.

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Stephen A. Ingham, Jamie S. Pringle, Sarah L. Hardman, Barry W. Fudge and Victoria L. Richmond

Purpose:

This study examined parameters derived from both an incremental step-wise and a ramp-wise graded rowing exercise test in relation to rowing performance.

Methods:

Discontinuous step-wise incremental rowing to exhaustion established lactate threshold (LT), maximum oxygen consumption (VO2maxSTEP), and power associated with VO2max (W VO2max). A further continuous ramp-wise test was undertaken to derive ventilatory threshold (VT), maximum oxygen consumption (VO2maxRAMP), and maximum minute power (MMW). Results were compared with maximal 2000-m ergometer time-trial power.

Results:

The strongest correlation with 2000-m power was observed for MMW (r = .98, P < .001), followed by W VO2max (r = .96; P < .001). The difference between MMW and W VO2max compared with the mean of MMW/W VO2max showed a widening bias with a greater difference coincident with greater power. However, this bias was reduced when expressed as a ratio term and when a baseline VO2 was accounted for. There were no differences (P = .85) between measures of VO2maxSTEP and VO2maxRAMP; rather, the measures showed strong association (r = .97, P < .001, limits of agreement = −0.43 to 0.33 L/min). The power at LT and VT did not differ (P = .6), and a significant association was observed (r = .73, P = .001, limits of agreement = −54.3 to 20.2 W, SEE = 26.1).

Conclusions:

This study indicates that MMW demonstrates a strong association with ergometer rowing performance and thus may have potential as an influential monitoring tool for rowing athletes.

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Christopher Byrne and Jason K.W. Lee

Declaration of Helsinki. A total of 24 of the 31 participants had complete TC and HR data sets and were included in this study (mean [SD]: age = 26 [3] y; body mass = 65.5 [6.5] kg; height = 1.72 [0.05] m; VO 2 peak = 59 [5] [51–68] mL·kg·min −1 ). Methodology At 4 weeks prior to the race, each individual

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Gustavo Monnerat, Alex S. Maior, Marcio Tannure, Lia K.F.C. Back and Caleb G.M. Santos

, VO 2 max, and recovery supported the possibility of genomic predictors affecting trainability. 7 – 11 However, few studies have examined the link between genetic factors within elite soccer players and their physiological and performance parameters. According to our hypothesis, using a complementary