118 research outputs found

    The steady state load of five firefighting tasks

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    Purpose. Physiologic demands of five common tasks in firefighting have been examined. Methods. Eight male volunteers, being dressed up as smoke divers (+21 kg extra load), carried out the following tasks at constant pace for 5 min: Walking at 1.4 m·s–1, walking (all walks at the same speed) while carrying a 10 kg ladder, walking carrying two hose packs of 16 kg together, walking carrying a 32 kg spreader tool, finally climbing up and down a ladder at preset pace. A 5 min break separated each exercise. Heart rate, O2-uptake and ventilation were measured continuously, and blood lactate con-centration was recorded after each task. Results. The end-exercise heart rate rose from 108 to 180 bpm from first to last task, blood lactate concentration rose from 1 to 7 mmol·L–1, O2-uptake rose from 19 to 48 ml·kg–1·min–1, and ventilation rose from 38 to 124 L·min–1. Discussion. Walking was an easy task even when dressed up as a smoke diver. Adding loads increased demands; ladder climbing taxed >90% of the subjects’ aerobic power. Conclusions. The physiologic demands varied considera-bly between different tasks.acceptedVersio

    Sports Nutrition: What the Future may Bring

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    The field of sports nutrition is a dynamic one. Core competencies in exercise physiology, psychology, integrated metabolism and biochemistry are the initial parameters for a successful career in sports nutrition. In addition to the academic fundamentals, it is imperative that the sports nutritionist understand the sport in which our client participates. This sport specific understanding should manifest itself in fuel utilization, mechanics of movement, as well as psychological processes that motivate the participant to perform optimally. Sports nutrition as a field has grown substantially over the past 50 years, from glycogen loading to today's scientifically validated ergogenic aids. The last ten years has seen the largest advancement of sports nutrition, with the following areas driving much of the research: the effects of exercise on protein utilization, meal timing to maximize the anabolic response, the potential for ribose to benefit those engaged in high-energy repetitive sports, and creatine and its uses within athletics and medicine. The future of sports nutrition will dictate that we 1) collectively strive for a higher standard of care and education for counseling athletes and 2) integrate different disciplines. We are in an era of unprecedented growth and the new knowledge is constantly evolving. The International Society of Sports Nutrition (ISSN) will contribute to this exciting field in many ways, and we ask for your contribution by sharing your passion, stories, research, and life experiences with us

    Dietary protein safety and resistance exercise: what do we really know?

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    Resistance trainers continue to receive mixed messages about the safety of purposely seeking ample dietary protein in their quest for stimulating protein synthesis, improving performance, or maintaining health. Despite protein's lay popularity and the routinely high intakes exhibited by strength athletes, liberal and purposeful protein consumption is often maligned by "experts". University textbooks, instructors, and various forms of literature from personal training groups and athletic organizations continue to use dissuasive language surrounding dietary protein. Due to the widely known health benefits of dietary protein and a growing body of evidence on its safety profile, this is unfortunate. In response, researchers have critiqued unfounded educational messages. As a recent summarizing example, the International Society of Sports Nutrition (ISSN) Position Stand: Protein and Exercise reviewed general literature on renal and bone health. The concluding remark that "Concerns that protein intake within this range [1.4 – 2.0 g/kg body weight per day] is unhealthy are unfounded in healthy, exercising individuals." was based largely upon data from non-athletes due to "a lack of scientific evidence". Future studies were deemed necessary. This assessment is not unique in the scientific literature. Investigators continue to cite controversy, debate, and the lack of direct evidence that allows it. This review discusses the few existing safety studies done specific to athletes and calls for protein research specific to resistance trainers. Population-specific, long term data will be necessary for effective education in dietetics textbooks and from sports governing bodies

    The short-term effect of high versus moderate protein intake on recovery after strength training in resistance-trained individuals

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    Background: Dietary protein intakes up to 2.9 g.kg-1.d-1 and protein consumption before and after resistance training may enhance recovery, resulting in hypertrophy and strength gains. However, it remains unclear whether protein quantity or nutrient timing is central to positive adaptations. This study investigated the effect of total dietary protein content, whilst controlling for protein timing, on recovery in resistance trainees. Methods: Fourteen resistance-trained individuals underwent two 10-day isocaloric dietary regimes with a protein content of 1.8 g.kg-1.d-1 (PROMOD) or 2.9 g.kg-1.d-1 (PROHIGH) in a randomised, counterbalanced, crossover design. On days 8-10 (T1-T3), participants undertook resistance exercise under controlled conditions, performing 3 sets of squat, bench press and bent-over rows at 80% 1 repetition maximum until volitional exhaustion. Additionally, participants consumed a 0.4 g.kg-1 whey protein concentrate/isolate mix 30 minutes before and after exercise sessions to standardise protein timing specific to training. Recovery was assessed via daily repetition performance, muscle soreness, bioelectrical impedance phase angle, plasma creatine kinase (CK) and tumor necrosis factor-α (TNF-α). Results: No significant differences were reported between conditions for any of the performance repetition count variables (p>0.05). However, within PROMOD only, squat performance total repetition count was significantly lower at T3 (19.7 ± 6.8) compared to T1 (23.0 ± 7.5; p=0.006). Pre and post-exercise CK concentrations significantly increased across test days (p≤0.003), although no differences were reported between conditions. No differences for TNF-α or muscle soreness were reported between dietary conditions. Phase angle was significantly greater at T3 for PROHIGH (8.26 ± 0.82°) compared with PROMOD (8.08 ± 0.80°; p=0.012). Conclusions: When energy intake and peri-exercise protein intake was controlled for, a short term PROHIGH diet did not improve markers of muscle damage or soreness in comparison to a PROMOD approach following repeated days of intensive training. Whilst it is therefore likely that protein intakes (1.8g.kg-1.d-1) may be sufficient for resistance-trained individuals, it is noteworthy that both lower body exercise performance and bioelectrical phase angle were maintained with PROHIGH. Longer term interventions are warranted to determine whether PROMOD intakes are sufficient during prolonged training periods or when extensive exercise (e.g. training twice daily) is undertaken

    Psychosocial impact of implantable cardioverter defibrillators (ICD) in young adults with Tetralogy of Fallot

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    Item does not contain fulltextOBJECTIVE: To investigate the psychosocial impact of having an implantable cardioverter defibrillator (ICD) in adults with Tetralogy of Fallot (ToF). METHODS: Included were 26 ToF-patients with an ICD (age 44 +/- 12 years), and two control groups consisting of 28 ToF-patients without an ICD (age 40 +/- 10 years) and a group of 35 ICD-patients of older age without ToF (age 72.0 +/- 8 years). This last control group was chosen to represent the "older general ICD population" with acquired heart disease seen at the out-patient clinic. Psychosocial functioning encompassed daily functioning, subjective health status, quality of life, anxiety, depression, coping and social support. RESULTS: ToF-patients with ICD showed diminished psychosocial functioning in comparison to ToF-patients without ICD. This was reflected by diminished subjectively perceived physical functioning (p = 0.01), general health perception (p < 0.01) and a lower satisfaction with life (p = 0.02). In comparison to older ICD-patients, ToF-patients with ICD showed less satisfaction with life (p = 0.03), experienced more anxiety (p = 0.01) and showed less favourable coping styles, although physical functioning was better for ToF-patients with ICD than for older ICD-patients (p = 0.01). More inappropriate shocks were found in ToF-patients with ICD compared to the older ICD-patients. CONCLUSION: In patients with ToF, ICD implantation had a major impact on psychosocial functioning which should be taken into account when considering ICD implantation in these young patients. To help improve psychosocial functioning, psychological counselling attuned to the specific needs of these patients may be useful.1 juli 201

    Leucine-enriched protein feeding does not impair exercise-induced free fatty acid availability and lipid oxidation: beneficial implications for training in carbohydrate-restricted states

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    Given that the enhanced oxidative adaptations observed when training in carbohydrate (CHO) restricted states are potentially regulated through free fatty acid (FFA) mediated signalling and that leucine rich protein elevates muscle protein synthesis, the present study aimed to test the hypothesis that leucine enriched protein feeding enhances circulating leucine concentration but does not impair FFA availability nor whole body lipid oxidation 56 during exercise. Nine males cycled for 2 h at 70% VO2peak when fasted (PLACEBO) or having consumed a whey protein solution (WHEY) or a leucine enriched whey protein gel (GEL), administered as 22 g 1 hour pre-exercise, 11 g/h during and 22 g thirty minutes post-exercise. Total leucine administration was 14.4 g and 6.3 in GEL and WHEY, respectively. Mean plasma leucine concentrations were elevated in GEL (P= 0.001) compared 60 with WHEY and PLACEBO (375 ± 100, 272 ± 51, 146 ± 14 μmol.L-1 respectively). No differences (P= 0.153) in plasma FFA (WHEY 0.53 ± 0.30, GEL 0.45 ± 0.25, PLACEBO 0.65 ± 0.30, mmol.L-1) or whole body lipid oxidation during exercise (WHEY 0.37 ± 0.26, GEL 0.36 ± 0.24, PLACEBO 0.34 ± 0.24 g/min) were apparent between trials, despite elevated (P= 0.001) insulin in WHEY and GEL compared with PLACEBO (38 ± 16, 35 ± 16, 22 ± 11 pmol.L-1 respectively). We conclude that leucine enriched protein feeding does not impair FFA availability nor whole body lipid oxidation during exercise, thus having practical applications for athletes who deliberately train in CHO restricted states to promote skeletal muscle adaptations

    Analysis of the Lung Microbiome in the “Healthy” Smoker and in COPD

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    Although culture-independent techniques have shown that the lungs are not sterile, little is known about the lung microbiome in chronic obstructive pulmonary disease (COPD). We used pyrosequencing of 16S amplicons to analyze the lung microbiome in two ways: first, using bronchoalveolar lavage (BAL) to sample the distal bronchi and air-spaces; and second, by examining multiple discrete tissue sites in the lungs of six subjects removed at the time of transplantation. We performed BAL on three never-smokers (NS) with normal spirometry, seven smokers with normal spirometry (“heathy smokers”, HS), and four subjects with COPD (CS). Bacterial 16 s sequences were found in all subjects, without significant quantitative differences between groups. Both taxonomy-based and taxonomy-independent approaches disclosed heterogeneity in the bacterial communities between HS subjects that was similar to that seen in healthy NS and two mild COPD patients. The moderate and severe COPD patients had very limited community diversity, which was also noted in 28% of the healthy subjects. Both approaches revealed extensive membership overlap between the bacterial communities of the three study groups. No genera were common within a group but unique across groups. Our data suggests the existence of a core pulmonary bacterial microbiome that includes Pseudomonas, Streptococcus, Prevotella, Fusobacterium, Haemophilus, Veillonella, and Porphyromonas. Most strikingly, there were significant micro-anatomic differences in bacterial communities within the same lung of subjects with advanced COPD. These studies are further demonstration of the pulmonary microbiome and highlight global and micro-anatomic changes in these bacterial communities in severe COPD patients

    Exercise and functional foods

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    Appropriate nutrition is an essential prerequisite for effective improvement of athletic performance, conditioning, recovery from fatigue after exercise, and avoidance of injury. Nutritional supplements containing carbohydrates, proteins, vitamins, and minerals have been widely used in various sporting fields to provide a boost to the recommended daily allowance. In addition, several natural food components have been found to show physiological effects, and some of them are considered to be useful for promoting exercise performance or for prevention of injury. However, these foods should only be used when there is clear scientific evidence and with understanding of the physiological changes caused by exercise. This article describes various "functional foods" that have been reported to be effective for improving exercise performance or health promotion, along with the relevant physiological changes that occur during exercise
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