Characteristics Explaining Performance in Downhill Mountain Biking

2015 ◽  
Vol 10 (2) ◽  
pp. 183-190 ◽  
Author(s):  
Joel B. Chidley ◽  
Alexandra L. MacGregor ◽  
Caoimhe Martin ◽  
Calum A. Arthur ◽  
Jamie H. Macdonald
Keyword(s):  
Aerobic Capacity ◽  
Interrater Reliability ◽  
Ventilatory Threshold ◽  
Anaerobic Power ◽  
Important Variable ◽  
Mountain Biking ◽  
Reliability Study ◽  
Self Confidence ◽  
Group 2 ◽  
Specific Contribution

Purpose:To identify physiological, psychological, and skill characteristics that explain performance in downhill (DH) mountainbike racing.Methods:Four studies were used to (1) identify factors potentially contributing to DH performance (using an expert focus group), (2) develop and validate a measure of rider skill (using video analysis and expert judge evaluation), (3) evaluate whether physiological, psychological, and skill variables contribute to performance at a DH competition, and (4) test the specific contribution of aerobic capacity to DH performance.Results:Study 1 identified aerobic capacity, handgrip endurance, anaerobic power, rider skill, and self-confidence as potentially important for DH. In study 2 the rider-skill measure displayed good interrater reliability. Study 3 found that rider skill and handgrip endurance were significantly related to DH ride time (β = –0.76 and –0.14, respectively; R2 = .73), with exploratory analyses suggesting that DH ride time may also be influenced by self-confidence and aerobic capacity. Study 4 confirmed aerobic capacity as an important variable influencing DH performance (for a DH ride, mean oxygen uptake was 49 ± 5 mL · kg−1 · min−1, and 90% of the ride was completed above the 1st ventilatory threshold).Conclusions:In order of importance, rider skill, handgrip endurance, self-confidence, and aerobic capacity were identified as variables influencing DH performance. Practically, this study provides a novel assessment of rider skill that could be used by coaches to monitor training and identify talent. Novel intervention targets to enhance DH performance were also identified, including self-confidence and aerobic capacity.

Interrater reliability of a method to assess hypothalamic involvement in pediatric adamantinomatous craniopharyngioma

2020 ◽  
Vol 25 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Ros Whelan ◽  
Eric Prince ◽  
David M. Mirsky ◽  
Robert Naftel ◽  
Aashim Bhatia ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Brain Tumors ◽  
Interrater Reliability ◽  
Statistical Evaluation ◽  
Grading System ◽  
Reliability Study ◽  
Postoperative Mri ◽  
Mri Scans ◽  
Adamantinomatous Craniopharyngioma

OBJECTIVEPediatric adamantinomatous craniopharyngiomas (ACPs) are histologically benign brain tumors that confer significant neuroendocrine morbidity. Previous studies have demonstrated that injury to the hypothalamus is associated with worsened quality of life and a shorter lifespan. This insight helps many surgeons define the goals of surgery for patients with ACP. Puget and colleagues proposed a 3-tiered preoperative and postoperative grading system based on the degree of hypothalamic involvement identified on MRI. In a prospective cohort from their institution, the authors found that use of the system to guide operative goals was associated with decreased morbidity. To date, however, the Puget system has not been externally validated. Here, the authors present an interrater reliability study that assesses the generalizability of this system for surgeons planning initial operative intervention for children with craniopharyngiomas.METHODSA panel of 6 experts, consisting of pediatric neurosurgeons and pediatric neuroradiologists, graded 30 preoperative and postoperative MRI scans according to the Puget system. Interrater reliability was calculated using Fleiss’ κ and Krippendorff’s α statistics.RESULTSInterrater reliability in the preoperative context demonstrated moderate agreement (κ = 0.50, α = 0.51). Interrater reliability in the postoperative context was 0.27 for both methods of statistical evaluation.CONCLUSIONSInterrater reliability for the system as defined is moderate. Slight refinements of the Puget MRI grading system, such as collapsing the 3 grades into 2, may improve its reliability, making the system more generalizable.

β-Adrenergic receptor number in human lymphocytes is inversely correlated with aerobic capacity

1998 ◽  
Vol 274 (6) ◽  
pp. E1106-E1112 ◽  
Author(s):  
Nobuharu Fujii ◽  
Sachiko Homma ◽  
Fumio Yamazaki ◽  
Ryoko Sone ◽  
Takeshi Shibata ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Aerobic Capacity ◽  
Adrenergic Receptor ◽  
Ventilatory Threshold ◽  
Human Lymphocytes ◽  
Mrna Level ◽  
Maximal Oxygen Consumption ◽  
Subsequent Degradation ◽  
Intracellular Compartments ◽  
Model Cell

In the present study, the relationships between β-adrenergic receptor (β-AR) expression and aerobic capacity evaluated by maximal oxygen consumption ([Formula: see text]) and oxygen consumption level at ventilatory threshold (V˙o 2@VT) were investigated. Seventeen physically untrained and 25 trained men participated in the study. After supine resting, the peripheral blood was sampled for preparation of lymphocytes, the model cell used to analyze the β-AR state. The total number of β-AR in lymphocytes (β-ARtotal) was inversely correlated with theV˙o 2 max( r = −0.368; P < 0.05) and theV˙o 2@VT ( r = −0.359; P < 0.05). Similar relationships were also observed between the number of β-AR in cell surface and both V˙o 2 max( r = −0.491; P < 0.05) andV˙o 2@VT ( r = −0.498; P < 0.05). However, no correlation was obtained between the number of β-AR in intracellular compartments and eitherV˙o 2 max orV˙o 2@VT. The β2-AR mRNA level quantified by the use of competitive reverse transcription-polymerase chain reaction was inversely correlated withV˙o 2@VT ( r = −0.567; P < 0.05) and positively correlated with β-ARtotal( r = 0.521; P < 0.05). These findings suggest that the β-AR number in lymphocytes is inversely correlated with aerobic capacity. This relationship may be explained by downregulation of β-AR, including internalization with subsequent degradation of the receptors and inhibition of the β-AR biosynthesis.

scholarly journals Aerobic capacity and respiratory patterns are better in recreational basketball-engaged university students than age-matched untrained males

2021 ◽  
Vol 13 (1) ◽  
pp. 111-120
Author(s):  
Mladen Mikić ◽  
Marko D.M. Stojanović ◽  
Aleksandra Milovančev ◽  
Tatjana Miljković ◽  
Marija Bjelobrk ◽  
...  
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
University Students ◽  
Aerobic Capacity ◽  
Ventilatory Threshold ◽  
Maximal Oxygen Consumption ◽  
Body Height ◽  
Time To Exhaustion ◽  
Respiratory Parameters ◽  
Recreational Basketball

Abstract Study aim: To asses and compare the aerobic capacity and respiratory parameters in recreational basketball-engaged university students with age-matched untrained young adults. Material and methods: A total of 30 subjects were selected to took part in the study based on recreational-basketball activity level and were assigned to a basketball (BG: n = 15, age 22.86 ± 1.35 yrs., body height 185.07 ± 5.95 cm, body weight 81.21 ± 6.15 kg) and untrained group (UG: n = 15, age 22.60 ± 1.50 yrs., body height 181.53 ± 6.11 cm, body weight 76.89 ± 7.30 kg). Inspiratory vital capacity (IVC), forced expiration volume (FEV1), FEV1/IVC ratio, maximal oxygen consumption (VO2max), ventilatory threshold (VO2VT) and time to exhaustion, were measured in all subjects. Student T-test for independent Sample and Cohen’s d as the measure of the effect size were calculated. Results: Recreational basketball-engaged students (EG) reached significantly greater IVC (t = 7.240, p < 0.001, d = 1.854), FEV1 (t = 10.852, p < 0.001, d = 2.834), FEV1/IVC ratio (t = 6.370, p < 0.001, d = 3.920), maximal oxygen consumption (t = 9.039, p < 0.001, d = 3.310), ventilatory threshold (t = 9.859, p < 0.001, d = 3.607) and time to exhaustion (t = 12.361, p < 0.001, d = 4.515) compared to UG. Conclusions: Long-term exposure to recreational basketball leads to adaptive changes in aerobic and respiratory parameters in male university students.

scholarly journals The relationship between relative aerobic load, energy cost, and speed of walking in individuals post-stroke

2021 ◽  
Author(s):  
Ilse Johanna Blokland ◽  
Arianne S Gravesteijn ◽  
Mathijs C Busse ◽  
Floor P Groot ◽  
Coen AM van Bennekom ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Aerobic Capacity ◽  
Energy Cost ◽  
Walking Speed ◽  
Ventilatory Threshold ◽  
Research Question ◽  
Walking Ability ◽  
Cross Sectional ◽  
Relative Load ◽  
Post Stroke

Background: Individuals post-stroke walk slower than their able-bodied peers, which limits participation. This might be attributed to neurological impairments, but could also be caused by a mismatch between aerobic capacity and aerobic load of walking. Research question: What is the potential impact of aerobic capacity and aerobic load of walking on walking ability post-stroke? Methods: In a cross-sectional study, forty individuals post-stroke (more impaired N=21; preferred walking speed (PWS)<0.8m/s, less impaired N=19), and 15 able-bodied individuals performed five, 5-minute treadmill walking trials at 70%, 85%, 100%, 115% and 130% of PWS. Energy expenditure (mlO2/kg/min) and energy cost (mlO2/kg/m) were derived from oxygen uptake (VO2). Relative load was defined as energy expenditure divided by peak aerobic capacity (%VO2peak) and by VO2 at ventilatory threshold (%VO2-VT). Relative load and energy cost at PWS were compared between groups with one-way ANOVAs. The effect of speed on these parameters was modeled with GEE. Results: Both more and less impaired individuals post-stroke showed lower PWS than able-bodied controls (0.44[0.19-0.76] and 1.04[0.81-1.43] vs 1.36[0.89-1.53] m/s) and higher relative load at PWS (50.2±14.4 and 51.7±16.8 vs 36.2±7.6 %VO2 peak and 101.9±20.5 and 97.0±27.3 vs 64.9±13.8 %VO2-VT). No differences in relative load were found between stroke groups. Energy cost at PWS of more impaired (0.30[.19-1.03] mlO2/kg/m) was higher than less-impaired (0.19[0.10-0.24] mlO2/kg/m) and able-bodied (0.15[0.13-0.18] mlO2/kg/m). For post-stroke individuals, increasing walking speed above PWS decreased energy cost, but resulted in a relative load above endurance threshold. Significance: Individuals post-stroke seem to reduce walking speed to prevent unsustainably high relative aerobic loads at the expense of reduced economy. When aiming to improve walking ability in individuals post-stroke, it is important to consider training aerobic capacity.

Influence of the Cyclist’s Characteristics on the Optimal Pacing Strategy for an Ascending Road

2021 ◽  
Author(s):  
Manuel Angulo ◽  
Alejandra Polanco ◽  
Luis Muñoz
Keyword(s):  
Aerobic Capacity ◽  
Anaerobic Power ◽  
Anaerobic Capacity ◽  
Power Delivery ◽  
Race Time ◽  
Pacing Strategy ◽  
Pacing Strategies ◽  
Road Grade ◽  
Aerobic And Anaerobic ◽  
Drag Area

Abstract Pacing strategies are used in cycling to optimize the power delivered by the cyclist during a race. Gains in race time have been obtained when using these strategies compared to self-paced approaches. For this reason, this study is focused on revising the effect that the variation of the cyclist’s parameters has on the pacing strategy and its results. A numeric method was used to propose pacing strategies for a cyclist riding on an ascending 3.7 km route with a constant 6.26% road grade. The method was validated and then implemented to study the effect of aerobic and anaerobic power delivery capacity, mass, and drag area on the pacing strategies and their corresponding estimated race times. The results showed that modifying 1% of the aerobic capacity or cyclist mass value led to a change of 1% on the race time. Modifying 1% the anaerobic capacity and the drag area led to changes of 0.03% and 0.02% on the race time, respectively. These results are strongly dependent on the route characteristics. It was concluded that for the studied route (constantly ascending), the variation of the cyclist’s aerobic capacity influences the pacing strategy (i.e., the power delivery over the distance). The anaerobic capacity and mass of the cyclist also influence the pacing strategy to a lesser extent.

Is Physical Attractiveness More Important than Professional Competency?

2016 ◽  
pp. 239-261
Author(s):  
Chien-Wen Tsai
Keyword(s):  
Work Environment ◽  
Physical Attractiveness ◽  
Professional Competence ◽  
Hotel Industry ◽  
Important Variable ◽  
Self Confidence ◽  
International Tourist ◽  
And Training ◽  
Positive Significant Correlation

The international tourist hotel industry that focuses on quality of the “tangible” service is a typical high-contact service. To survive in the recent competitive work environment, many enterprises enhance their competitiveness in the process of service employee selection and emphasize the importance of physical attractiveness. This study uses self-confidence as a moderator which is rare relevant empirical evidence to confirm the relationships between physical attractiveness, professional competence and service attitude. The results show that confidence of the service personnel, physical attractiveness and professional competence have positive significant correlation relationships with service attitude. Service personnel's “self-confidence” is the most important variable towards service attitude. The study borrows selection and training functions of human resource management to integrate the knowledge of psychology, marketing management to expand the theory.

Self-Managed Surveillance for Breast Cancer–Related Upper Body Issues: A Feasibility and Reliability Study

2020 ◽  
Vol 100 (3) ◽  
pp. 468-476 ◽  
Author(s):  
Bolette S Rafn ◽  
Chiara A Singh ◽  
Julie Midtgaard ◽  
Pat G Camp ◽  
Margaret L McNeely ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Interrater Reliability ◽  
Physical Therapist ◽  
Retention Rates ◽  
Upper Body ◽  
Intrarater Reliability ◽  
Prospective Surveillance ◽  
Reliability Study ◽  
Shoulder Flexion ◽  
Arm Circumference

Abstract Background Early identification of breast cancer–related upper body issues is important to enable timely physical therapist treatment. Objective This study evaluated the feasibility and reliability of women performing self-managed prospective surveillance for upper body issues in the early postoperative phase as part of a hospital-based physical therapy program. Design This was a prospective, single-site, single-group feasibility and reliability study. Methods Presurgery arm circumference measurements were completed at home and at the hospital by participants and by a physical therapist. Instruction in self-measurement was provided using a video guide. After surgery, all circumference measurements were repeated along with self-assessment and therapist assessment for shoulder flexion and abduction active range of motion. Feasibility was determined by recruitment/retention rates and participant-reported ease of performing self-measurements (1 [very difficult] to 10 [very easy]). Reliability was determined as intrarater reliability, interrater reliability, and agreement. Results Thirty-three women who were 53.4 (SD = 11.4) years old participated, with recruitment and retention rates of 79% and 94%, respectively. Participant-reported ease of measurement was 8.2 (SD = 2.2) before surgery and 8.0 (SD = 1.9) after surgery. The intrarater reliability and interrater reliability were excellent before surgery (intraclass correlation coefficient [ICC] ≥ 0.94; 95% confidence interval = 0.87–0.97) and after surgery (ICC ≥ 0.91; 95% confidence interval = 0.76–0.96). Agreement between self-assessed and therapist-assessed active shoulder flexion (κ = 0.79) and abduction (κ = 0.71) was good. Limitations Further testing is needed using a prospective design with a longer follow-up to determine whether self-managed prospective surveillance and timely treatment can hinder the development of chronic breast cancer–related upper body issues Conclusions Self-measured arm circumference and shoulder range of motion are reliable, and their inclusion in a hospital-based program of prospective surveillance for upper body issues seems feasible. This approach may improve early detection and treatment

Sign in / Sign up

Export Citation Format

Share Document