Johnsonhowe4309

The aims of this study were to 1) compare active drag (Da) calculation between a single land-based measurement of frontal surface area (FSA) and in-water FSA measures obtained at key events of the arm pull (1, right upper-limb catch; 2, right upper-limb insweep; 3, right upper-limb exit and left upper-limb catch; 4, left upper-limb insweep; and 5, left upper-limb exit and right upper-limb catch) at front crawl swimming, and 2) compare mechanical power variables computed based on these two approaches.

Seventeen swimmers (11, male; 6, female; 16.15 ± 0.94 yr old) were recruited. The FSA was measured based on two approaches (i) nonvariation, that is, assuming a constant value, and (ii) variation, that is, calculated in each key event of the front crawl swim. Active drag based on a nonvariation of the FSA was measured using the Velocity Perturbation method. Active drag based on a variation approach was measured in each key event of the front crawl according to the law of linear motion. Paired t-test (P ≤ 0.05), simple linear regression models, and Bland-Altman plots between assessment methods (variation vs nonvariation) were computed.

The FSA (variation) was higher than when assuming a nonvariation (0.1110 ± 0.010 vs 0.0968 ± 0.010 m, Δ = 15.69%, t = 4.40, P < 0.001, d = 0.95). Active drag (variation) was also significantly higher than when assuming a nonvariation (88.44 ± 25.92 vs 75.41 ± 15.11 N, Δ = 16.09%, t = 3.66, P = 0.002, d = 0.61).

Besides the FSA, swim velocity also changes during the front crawl arm pull. The variation of both variables had a significant effect on the active drag measurement and consequently on mechanical power and total power input variables.

Besides the FSA, swim velocity also changes during the front crawl arm pull. The variation of both variables had a significant effect on the active drag measurement and consequently on mechanical power and total power input variables.

Sport-related head impact biomechanics research has been male-centric and focused primarily on American football and ice hockey, which do not address popular sports in which both sexes participate. The purpose of this study was to quantify college female and male lacrosse and soccer head impact biomechanics.

Head impact biomechanics were collected from college lacrosse and soccer players across two Division 1 college athletic programs (96 female athletes, 141 male athletes; age, 19.8 ± 1.3 yr; height, 174.8 ± 9.2 cm; mass, 72.4 ± 11.7 kg). We deployed helmetless head impact measurement devices (X2 Biosystems xPatch) before each event. Peak linear and rotational accelerations were log-transformed for random intercepts general linear mixed models, and subsequently categorized based on impact magnitude for additional categorical analyses.

Most linear (69.4%) and rotational (72.3%) head impact accelerations sustained by our study cohort were categorized as mild. On average, male athletes sustained impacts wvalidate nonhelmeted head impact technologies.

Male athletes and lacrosse athletes experience higher-magnitude head impacts. selleck Given the limited literature in this area, future research should continue characterizing head impact biomechanics in women's and nonhelmeted sports as well as validate nonhelmeted head impact technologies.

Cancer-related fatigue and muscle wasting have received significant attention over the last few decades with the goal of establishing interventions that can improve cancer patient life quality and survival. Increased physical activity has shown to reduce cancer-associated fatigue and has been proposed as a promising therapeutic to attenuate cancer-induced wasting. However, significant gaps remain in our understanding of how physical activity affects the compositional and functional changes that initiate muscle wasting. The purpose of the current study was to determine the effect of wheel exercise on body composition and functional indices of cancer cachexia before the development of significant wasting.

Thirteen-week-old male Apc (MIN) and C57BL/6 (B6) mice were given free wheel access (W) or a locked wheel (Sed) for 5 wk.

Wheel activity was reduced in the MIN compared with B6; however, wheel access increased complex II expression in isolated skeletal muscle mitochondria regardless of genotype. Wheel acere was an exercise threshold needed to improve skeletal muscle fatigability in tumor-bearing mice. Interestingly, wheel access was able to improve compositional and functional outcomes without mitigating tumor number or size.

Thoracic gas compression and exercise-induced bronchodilation can influence the assessment of expiratory flow limitation (EFL) during cardiopulmonary exercise tests. The purpose of this study was to examine the effect of thoracic gas compression and exercise-induced bronchodilation on the assessment of EFL in children with and without obesity.

Forty children (10.7 ± 1.0 yr; 27 obese; 15 with EFL) completed pulmonary function tests and incremental exercise tests. Inspiratory capacity maneuvers were performed during the incremental exercise test for the placement of tidal flow volume loops within the maximal expiratory flow volume (MEFV) loops, and EFL was calculated as the overlap between the tidal and the MEFV loops. MEFV loops were plotted with volume measured at the lung using plethysmography (MEFVp), with volume measured at the mouth using spirometry concurrent with measurements in the plethysmograph (MEFVm), and from spirometry before (MEFVpre) and after (MEFVpost) the incremental exercise test. Only of EFL. Because most commercially available metabolic measurement systems do not correct for thoracic gas compression during spirometry, there may be a significant overdiagnosis of EFL in cardiopulmonary exercise testing. Therefore, clinicians must exercise caution while interpreting EFL when the MEFV loop is derived through spirometry.

We designed the study to determine whether mitochondrial DNA (mtDNA) haplogroup, sequence, and heteroplasmy differed between individuals previously characterized as low (LR) or high responders (HR) as defined by their maximal oxygen uptake response to a standardized aerobic exercise training program.

DNA was isolated from whole blood in subjects from the HERITAGE Family Study that were determined to be either HR (n = 15) or LR (n = 15). mtDNA was amplified by long-range polymerase chain reaction, then tagged with Nextera libraries and sequenced on a MiSeq instrument.

Different mtDNA haplogroup subtypes were found in HR and LR individuals. Compared with HR subjects, significantly more LR subjects had variants in 13 sites, including 7 in hypervariable (HV) regions HV2 (G185A 0 vs 6, P = 0.02; G228A 0 vs 5, P = 0.04; C295T 0 vs 6; P = 0.04), HV3 (C462T 0 vs 5, P = 0.04; T489C 0 vs 5; P = 0.04), and HV1 (C16068T 0 vs 6, P = 0.02; T16125C 0 vs 6, P = 0.02). Remaining variants were in protein coding genes, mtND1 (1 vs 8, P = 0.