Influence of adult role modeling on child/adolescent helmet use in recreational sledging: an observational study.

Background: During recreational sledging (tobogganing), the head represents the most frequent injured body region with approximately one-third of all sledging injuries among children and adolescents. Whether children are wearing a helmet or not might be influenced on parental encouragement and role modeling of helmet use. Therefore, the aim of this study was to evaluate the impact of adult helmet use on child/adolescent helmet use in recreational sledging.

Effects of short-term antioxidant supplementation on oxidative stress and exercise performance in the heat and the cold.

The effects of short-term as well as long-term antioxidant supplementation on exercise performance in the heat or the cold are unknown. Based on our recent studies we hypothesized that short-term supplementation with alpha-ketoglutaric acid (α-KG) and 5-hydroxymethylfurfural (5-HMF) would decrease oxidative stress but without significant impairment of maximal exercise performance in the heat or the cold. During a 5-week period young and welltrained participants performed 5 incremental treadmill tests to exhaustion under different temperature conditions (normal: 20°C, cold: +7°C, heat: +33°C) and with different nutritional supplements (placebo or α-KG and 5-HMF) prior to the tests applying a randomized cross over design.

Effect of 3-week high-intensity interval training on VO2max, total haemoglobin mass, plasma and blood volume in well-trained athletes.

Purpose: This study examined the haematological adaptations to high-intensity interval training (HIT), i.e. total haemoglobin mass (tHb-mass), blood volume (BV), and plasma volume (PV), and its effects on VO2max in well-trained athletes.

Factors Associated with the Perception of Speed among Recreational Skiers.

Background: Skiers have to differ between slow to moderate and fast skiing speed to determine their skiing style according to the ISO 11088 standard for setting binding release values. Despite existing evidence that males ski significantly faster than females, no sex-specific factor was inserted into the ISO 11088 standard.

Objective: To evaluate factors potentially associated with the perception of individual skiing speed among recreational skiers.

[Physical inactivity and chronic diseases].

The genetic program of contemporary human beings is still that of hunters and gatherers of the Stone Age, dedicated to optimal storage of energy for physical activities in hunger periods. Life-style of humans living in western industrial countries however, is often characterized by physical inactivity and overeating. The resulting positive energy balance is associated with fat accumulation (abdomen, liver, skeletal and heart muscle) followed by insulin resistance, glucose intolerance, mitochondrial dysfunction, oxidative stress and reduced production of nitric oxide, endothelial dysfunction and chronic inflammatory processes.

Hypoxia, Oxidative Stress and Fat.

Metabolic disturbances in white adipose tissue in obese individuals contribute to the pathogenesis of insulin resistance and the development of type 2 diabetes mellitus. Impaired insulin action in adipocytes is associated with elevated lipolysis and increased free fatty acids leading to ectopic fat deposition in liver and skeletal muscle. Chronic adipose tissue hypoxia has been suggested to be part of pathomechanisms causing dysfunction of adipocytes.

Favourable changes of the risk-benefit ratio in alpine skiing.

During the past five decades recreational alpine skiing has become increasingly safer. The numerous annual media reports on ski injuries have to be interpreted on the basis of the tremendous numbers of skiers. These favourable changes seem primarily be due to the introduction of short carving skis, more rigid and comfortable ski boots, the use of protective gear like helmets, and the optimized preparation of ski slopes.

Diagnosis and prediction of the occurrence of acute mountain sickness measuring oxygen saturation--independent of absolute altitude?

Purpose: Commercialization of trekking tourism enables untrained persons to participate in trekking tours. Because hypoxia is one of the main purported triggers for acute mountain sickness (AMS), pulse oximetry, which measures arterial oxygen saturation (SPO2), is discussed to be a possible and useful tool for the diagnosis of AMS. The purpose of this study was to evaluate possible associations between SPO2 values and the occurrence of AMS.

Normobaric Intermittent Hypoxia over 8 Months Does Not Reduce Body Weight and Metabolic Risk Factors--a Randomized, Single Blind, Placebo-Controlled Study in Normobaric Hypoxia and Normobaric Sham Hypoxia.

Objective: Both a 1- to 4-week continuous or intermittent stay and moderate exercise in hypoxia versus normoxia can lead to weight loss. We examined the reproducibility and durability of added hypoxic exposure in a feasible health program of several months.

Methods: 32 obese persons, randomly assigned to either a hypoxia (age 50.

Heart rate and blood pressure responses during hypoxic cycles of a 3-week intermittent hypoxia breathing program in patients at risk for or with mild COPD.

The aim of this study was to provide information on heart rate and blood pressure responses during a 3-week intermittent hypoxia breathing program in COPD patients. Sixteen participants with COPD symptoms were randomly assigned to a hypoxia or control group and completed a 3-week intermittent hypoxia breathing program (five sessions per week, each consisting of three to five breathing cycles, each cycle lasting 3-5 minutes with 3-minute breaks between cycles). During the breathing cycles, the hypoxia group received hypoxic air (inspired fraction of oxygen 15%-12%), whereas the control group received normal air (sham hypoxia).

Dental Occlusion Influences the Standing Balance on an Unstable Platform.

Contradictory results are still reported on the influence of dental occlusion on the balance control. We attempted to determine whether there are differences in balance between opposed dental occlusion (Intercuspal position (ICP)/"Cotton rolls" mandibular position [CR]) for two extreme levels of stability (stable/ unstable). Twenty-five subjects were monitored under both dental occlusion and level of stability conditions using an unstable platform Balance System SD.

Acetazolamide pre-treatment before ascending to high altitudes: when to start?

Hypoxia is the main responsible factor initiating the symptoms of acute mountain sickness (AMS) in susceptible individuals. Measures that improve oxygenation and/or hasten acclimatization like pre-treatment with acetazolamide will prevent the development of AMS. We hypothesized that pre-treatment with acetazolamide the day before arrival at high altitude would elicit improved oxygenation compared to placebo not until the second day of high-altitude exposure.

Differing levels of acute hypoxia do not influence maximal anaerobic power capacity.

Objective: The purpose of this study was to determine the effects of different inspired oxygen fractions (Fio2) on average and peak power capacity during consecutive jumps to assess the effectiveness of a hypoxic explosive-strength program.

Methods: Eight physically active subjects (aged 33.62 ± 4.

Performance limitation and the role of core temperature when wearing light-weight workwear under moderate thermal conditions.

The objective of this investigation was to achieve an understanding about the relationship between heat stress and performance limitation when wearing a two-layerfire-resistant light-weight workwear (full-clothed ensemble) compared to an one-layer short sports gear (semi-clothed ensemble) in an exhaustive, stressful situation under moderate thermal condition (25°C). Ten well trained male subjects performed a strenuous walking protocol with both clothing ensembles until exhaustion occurred in a climatic chamber. Wearing workwear reduced the endurance performance by 10% (p=0.

Is There a Link Between Physical Activity and Alcohol use?

Physical activity (PA) is discussed as a protective factor as well as a risk factor for alcohol consumption. Therefore, this study aimed at exploring a potential relationship between these behaviors. In a population-based cross-sectional study of 15,474 people living in Austria physical activity, alcohol consumption and demographic variables were assessed.

Shuttle-run sprint training in hypoxia for youth elite soccer players: a pilot study.

The purposes of the present study were to investigate if a) shuttle-run sprint training performed in a normobaric hypoxia chamber of limited size (4.75x2.25m) is feasible, in terms of producing the same absolute training load, when compared to training in normoxia, and b) if such training improves the repeated sprint ability (RSA) and the Yo-Yo intermittent recovery (YYIR) test outcome in young elite soccer players.

Symptom progression in acute mountain sickness during a 12-hour exposure to normobaric hypoxia equivalent to 4500 m.

The diagnosis and quantification of severity of acute mountain sickness (AMS) continue to be problematic. What symptoms should be included in a score and how to weigh any given symptom in the total score remain matter of debate. Seventy seven healthy male (n=43) and female (n=34) volunteers, aged between 18 and 42 years, were exposed to normobaric hypoxia (Fio2=12.

Bioimpedance identifies body fluid loss after exercise in the heat: a pilot study with body cooling.

Purpose: Assessment of post-exercise changes in hydration with bioimpedance (BI) is complicated by physiological adaptations that affect resistance (R) and reactance (Xc) values. This study investigated exercise-induced changes in R and Xc, independently and in bioelectrical impedance vector analysis, when factors such as increased skin temperature and blood flow and surface electrolyte accumulation are eliminated with a cold shower.

Methods: Healthy males (n = 14, 24.

Effects of living at higher altitudes on mortality: a narrative review.

Beside genetic and life-style characteristics environmental factors may profoundly influence mortality and life expectancy. The high altitude climate comprises a set of conditions bearing the potential of modifying morbidity and mortality of approximately 400 million people who are permanently residing at elevations above 1500 meters. However, epidemiological data on the effects of high altitude living on mortality from major diseases are inconsistent probably due to differences in ethnicity, behavioral factors and the complex interactions with environmental conditions.

Prevalence of obesity and motor performance capabilities in Tyrolean preschool children.

Background: The childrens' world of movement has changed dramatically during the last decades. As a consequence motor performance decreases particularly in children affected by overweight and obesity. This study analyses the influence of the body mass index (BMI) on motor performance of pre-school children.