Swimming in ice cold water

Introduction: We investigated two athletes swimming in 4°C for 23min (1.3km, swimmer 1) and 42min (2.2km, swimmer 2), respectively. Materials and methods: Pre swim, percent body fat was determined; post swim, core temperature was measured. Results: The core temperature of swimmer 2 was: 37.0°C immediately before the start, 32°C 20min after getting out of the water, and 35.5°C 80min after finishing the swim. Conclusion: We assume that the higher skin-fold thickness and body fat of swimmer 2 enabled him to perform longer. In addition to this, mental power and experience in cold water swimming must be considered. In any athlete aiming at swimming in water of less than 5°C, body core temperature and heart rate should be continuously monitored in order to detect a body core temperature below 32°C and arrhythmia to pull the athlete out of the water before life-threatening circumstances occu

Mein Rücken schmerzt so sehr!

Osteoporosis is a disease of older people with preference for the female sex. A bilateral fracture of the sacrum in a premenopausalwomanwith osteoporosis is very rare. We describe the case of a 34-year-old premenopausal woman suffering a bilateral sacral fracture after lifting a bundle of paper. The reason for these fractures was a primary osteoporosis with the risk factors vitamin D insufficiency, smoking, decreased alimentary calcium intake, physical inactivity and nulliparity

A case study evaluation of competitors undertaking an antarctic ultra-endurance event: nutrition, hydration and body composition variables

Background: The nutritional demands of ultra-endurance racing are well documented. However, the relationship between nutritional consumption and performance measures are less obvious for athletes competing in Polar conditions. Therefore, the aim of this study was to evaluate dietary intake, hydration status, body composition and performance times throughout an 800-km Antarctic race. Methods: The event organisers declared that 17 competitors would participate in the South Pole race. Of the 17 competitors, pre-race data were collected from 13 participants (12 males and 1 female (M±SD): age: 40.1±8.9 years; weight 83.9±10.3kg; and body fat percentage: 21.9±3.8%). Dietary recall, body composition and urinary osmolarity were assessed pre-race, midway checkpoint and end race. Data were compared on the basis of fast finishers (the Norwegian team (n=3) who won in a record of 14 day) and slower finishers (the remaining teams (n=10) reaching the South Pole between 22 and 28 days). Results: The percentage contribution of macronutrients to daily energy intake for all participants was as follows: carbohydrate (CHO) - 23.7% (221±82 g.day-1), fat = 60.6% (251±127g.day-1) and protein = 15.7% (117±52g.day-1). Energy demands were closer met by faster finishers compared to slower finishers (5,332±469 vs. 3,048±1,140kcal.day-1, p=0.02). Average reduction in body mass throughout the race was 8.3±5.5kg, with an average loss of lean mass of 2.0±4.1kg. There as a significant negative correlation between changes in lean mass and protein intake (p=0.03), and lean mass and energy intake (p=0.03). End-race urinary osmolarity was significantly elevated for faster finishers compared to slower finishers and control volunteers (faster finishers: 933±157mOsmol.L-1; slower finishers: 543±92mOsmol.L-1; control: 515±165mOsmol.L-1, p+0.04). Conclusions: Throughout the race, both groups were subjected to a negative change in energy balance which partly explained reduced body mass. Carbohydrate availability was limited inferring a greater reliance on fat and protein metabolism. Consequently, loss in fat-free mass was more prevalent with insufficient protein and caloric intake, which may relate to performance

Effects of moderate- vs. high-intensity interval training on physical fitness, enjoyment, and affective valence in overweight/obese female adolescents: a pre-/post-test study

OBJECTIVE The aim of this study was to compare the effects of 12-week moderate-intensity interval training (MIIT) vs. high-intensity interval training (HIIT) on body composition, physical fitness, and psychological valence in overweight/obese (OW/OB) female adolescents. PATIENTS AND METHODS Thirty-eight OW/OB female students were randomized into HIIT (n=13), MIIT (n=13) or control (n=12) groups. The participants underwent a 12-week interval-training program at 100% to 110% and 60% to 75% of maximal aerobic speed for HIIT and MIIT, respectively. The control group kept their usual physical activity without completing the training program. Pre- and post-training measurements were performed to assess body composition, aerobic capacity, and anaerobic performance (using selected tests evaluating speed, jumping ability, and strength). Ratings of perceived exertion and the feeling scale were evaluated every three weeks. Enjoyment was measured at the end of the program. A two-way analysis of variance with repeated measurements was applied to test for "group×time" interactions for body composition, physical fitness, and affective variables. RESULTS Significant "group×time" interactions were detected for aerobic and anaerobic performance, body composition indices, and the feeling scale. HIIT resulted in more noticeable improvements in body composition and physical performance than MIIT, while no significant changes were found in the control group. Throughout the program, the feeling score has progressively increased in the MIIT group but decreased in the HIIT group. Ratings of the perceived exertion have increased in both groups, more noticeably in the HIIT group. At the end of the program, the MIIT group showed a higher enjoyment score. CONCLUSIONS Despite offering better body composition improvement and physical fitness enhancement, HIIT offered lesser enjoyment and affective valence than MIIT in OW/OB female adolescents. MIIT might be an alternative time-efficient protocol for improving health in this population

Exercise, Telomeres, and Cancer: “The Exercise-Telomere Hypothesis”

Telomeres are genomic complex at the end of chromosomes that protects the DNA and telomere length (TL) is related to several age-related diseases, lifespan, and cancer. On the other hand, cancer is a multifactorial disease that is responsible for reduce the quality of life and kills millions of people every year. Both, shorter TL and cancer are related and could be treated or prevented depending of the lifestyle. In this review we discuss the possible role of exercise in the relationship between shorter telomeres, telomerase activity, and cancer. In summary, there is evidence that exercise leads to less telomere attrition and exercise also may diminish the risk of cancer, these two outcomes are possible intermediated by a reduction in oxidative stress, and chronic inflammation. Although, there is evidence that shorter TL are associated with cancer, the possible mechanisms that one may lead to the other remains to be clarified. We assume that humans under cancer treatment may suffer a great decrease in quality of life, which may increase sedentary behavior and lead to increased telomere attrition. And those humans with already shorter TL likely lived under a poor lifestyle and might have an increased risk to have cancer

No effect of short-term amino acid supplementation on variables related to skeletal muscle damage in 100 km ultra-runners - a randomized controlled trial

Background: The purpose of this study was to investigate the effect of short-term supplementation of amino acids before and during a 100 km ultra-marathon on variables of skeletal muscle damage and muscle soreness. We hypothesized that the supplementation of amino acids before and during an ultra-marathon would lead to a reduction in the variables of skeletal muscle damage, a decrease in muscle soreness and an improved performance. Methods: Twenty-eight experienced male ultra-runners were divided into two groups, one with amino acid supplementation and the other as a control group. The amino acid group was supplemented a total of 52.5 g of an amino acid concentrate before and during the 100 km ultra-marathon. Pre- and post-race, creatine kinase, urea and myoglobin were determined. At the same time, the athletes were asked for subjective feelings of muscle soreness. Results: Race time was not different between the groups when controlled for personal best time in a 100 km ultra-marathon. The increases in creatine kinase, urea and myoglobin were not different in both groups. Subjective feelings of skeletal muscle soreness were not different between the groups. Conclusions: We concluded that short-term supplementation of amino acids before and during a 100 km ultra-marathon had no effect on variables of skeletal muscle damage and muscle soreness

Effects of high-intensity interval training and plyometric exercise on the physical fitness of junior male handball players

OBJECTIVE This study analyzed the effects of high intensity interval training (HIIT) combined with plyometric exercise on the physical fitness of junior male handball players. PATIENTS AND METHODS Subjects (age ~17 years) were randomly divided between experimental (n=17) and control (n=15) groups. During the 8-week intervention, the experimental group replaced a part of their regular regimen by HIIT, combined with plyometric exercise. Assessments in both groups before and after the intervention included: squat jump (SJ), countermovement jump (CMJ), sprint performance (5 m, 10 m, 20 m and 30 m), change of direction tests (Illinois modified test [Illinois-MT] and T-half test), 20-m shuttle run, and repeated sprint T-test. RESULTS The two-way analyses of variance revealed significant group-time interactions (all p<0.05), favoring the intervention group in 5 m, 10 m, 20 m and 30 m sprint (d=0.33, 8.3%; d=0.52, 7.6%; d=0.57, 6.8%; and d=0.58, 8.8%, respectively), T-half (d=0.25, 5.1%), Illinois-MT (d=0.47, 4.2%), SJ and CMJ (d=0.34-0.39, 34-4-34.9%), repeated sprint T-test best time, mean time and total time (d=0.83, 6.9%; d=0.62, 7.4%; and d=0.61, 7.2%, respectively), 20 meter shuttle run test aerobic maximum speed and predicted maximal oxygen intake (d=0.36, 7.5%; d=0.19, 9.4%, respectively). CONCLUSIONS HIIT combined with plyometrics can aid in the development of physical fitness abilities, which are extremely important to junior male handball players