Objective: To establish the three-dimensional finite element model of lumbar motion segment (L4-L5) that considers material property and geometrical behave, to investigate mechanical characteristics of lumbar spinal motion segment for application of prevention and reduction of lumbar trauma for the speed skating athletes. Methods: three-dimensional finite element model (FEM) of the human lumbar...

PURPOSE This study aimed (1) to determine whether paced breathing (synchronization of the expiration phase with poling time) would reduce the metabolic rate and dictate a lower rate of perceived exertion (RPE) than does spontaneous breathing and (2) to analyze the effects of paced breathing on poling forces and stride-mechanics organization during roller-ski skating exercises. METHODS Thirtee...

BACKGROUND There has been rapid growth in the technical and physiologic demands made on skaters who perform more and more difficult jumps, spins, lifts, throws, and free skating movements. PURPOSE To investigate the frequency of injuries and overuse syndromes in elite junior skaters. STUDY DESIGN Questionnaire. METHODS During four consecutive Junior World Figure Skating Championships and ...

BACKGROUND We examined the covarying patterns of physical activity and sedentary behaviors among adolescents and their long-term maintenance. METHODS Data came from the National Longitudinal Study of Adolescent Health (1995-2002). We used latent class analysis to identify distinct covarying patterns in adolescence. Logistic regression models were used to predict odds of meeting moderate-to-vi...

The present study investigated the physiological characteristics of eight world-class (WC) and eight national-class (NC) Norwegian sprint cross country skiers. To measure the physiological response and treadmill performance, the skiers performed a submaximal test, a peak aerobic capacity (VO2peak) test, and a peak treadmill speed (V(peak)) test in the skating G3 technique. Moreover, the skiers ...

The main drop-out reasons from the sport of roller skating amongst Iranian youth skaters has been examined. A questionnaire with 53 items (adopted from Enoksen, 2011) representing seven subscales namely: training factors and facilities, executive factors and team, education and work obligations, motivational aspects, social-cultural environment, choice of other sport activities and interests an...

BACKGROUND The reported prevalence of exercise induced asthma (EIA) in elite winter athletes ranges from 9% to 50%. Many elite winter athletes do not report symptoms of EIA. At present there is no gold standard test for EIA. OBJECTIVE To establish the efficacy of screening for EIA and examine the role of the eucapnic voluntary hyperventilation (EVH) challenge and laboratory based and sport sp...

There are thousands of indoor ice rink arenas in the United States, Canada, and Europe. The combustion byproducts from the fuel powered ice resurfacing equipment impose a potential health risk to both athletes and spectators. A field survey of ten ice rink arenas in Greater Boston and Halifax, Nova Scotia indicates that the fuel type used by the resurfacer as well as the air exchange rate, the ...

PURPOSE This study assessed the effect of time spent in several race sectors (S) on finishing time and determined the variance in distribution of skating time and in total race time for official 1000-m sprint races conducted during a competitive season. METHODS Total race and sector times for the first 200 m (S1) and the following two 400-m laps (S2 and S3) of 34 female and 31 male elite spee...

In many endurance sports, a large part of an athlete’s external power is used to overcome drag. This force has 3 components: friction, pressure, and, in swimming, wave drag. When the athlete’s velocity is very low, friction drag dominates. In normal sports activities, pressure drag dominates, but frictional drag is influential in the velocity range in which the airstream changes from laminar to...