| 11. |
- Hahn, RG, et al.
(författare)
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An aggregate urine analysis tool to detect acute dehydration
- 2013
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Ingår i: International journal of sport nutrition and exercise metabolism. - : Human Kinetics. - 1543-2742 .- 1526-484X. ; 23:4, s. 303-311
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Tidskriftsartikel (refereegranskat)abstract
- Urine sampling has previously been evaluated for detecting dehydration in young male athletes. The present study investigated whether urine analysis can serve as a measure of dehydration in men and women of a wide age span.Methods:Urine sampling and body weight measurement were undertaken before and after recreational physical exercise (median time: 90 min) in 57 volunteers age 17–69 years (mean age: 42). Urine analysis included urine color, osmolality, specific gravity, and creatinine.Results:The volunteers’ body weight decreased 1.1% (mean) while they exercised. There were strong correlations between all 4 urinary markers of dehydration (r = .73–.84, p < .001). Researchers constructed a composite dehydration index graded from 1 to 6 based on these markers. This index changed from 2.70 before exercising to 3.55 after exercising, which corresponded to dehydration of 1.0% as given by a preliminary reference curve based on 7 previous studies in athletes. Men were slightly dehydrated at baseline (mean: 1.9%) compared with women (mean: 0.7%; p < .001), though age had no influence on the results. A final reference curve that considered both the present results and the 7 previous studies was constructed in which exercise-induced weight loss (x) was predicted by the exponential equation x = 0.20 dehydration index1.86.Conclusion:Urine sampling can be used to estimate weight loss due to dehydration in adults up to age 70. A robust dehydration index based on four indicators reduces the influence of confounders.
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| 12. |
- Hall, Ulrika Andersson, et al.
(författare)
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Metabolism and Whole-Body Fat Oxidation Following Post-Exercise Carbohydrate or Protein Intake.
- 2018
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Ingår i: International journal of sport nutrition and exercise metabolism. - : Human Kinetics. - 1543-2742 .- 1526-484X. ; 28:1, s. 37-45
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated how post-exercise intake of placebo (PLA), protein (PRO) or carbohydrate (CHO) affected fat oxidation (FO) and metabolic parameters during recovery and subsequent exercise.In a cross-over design, 12 moderately trained women (VO2max 45 ± 6 ml·min(-1)·kg(-1)) performed three days of testing. A 23 min control (CON) incremental FO bike test (30-80% VO2max) was followed by 60 min exercise at 75% VO2max. Immediately post-exercise, subjects ingested PLA, 20 g PRO or 40 g CHO followed by a second FO bike test 2h later.Maximal fat oxidation (MFO) and the intensity at which MFO occurs (Fatmax) increased at the second FO test compared to the first following all three post-exercise drinks (MFO for CON=0.28±0.08, PLA=0.57±0.13, PRO=0.52±0.08, CHO=0.44±0.12 g fat·min(-1); Fatmax for CON=41±7, PLA=54±4, PRO=55±6, CHO=50±8 %VO2max, P<0.01 for all values compared to CON). Resting FO, MFO and Fatmax were not significantly different between PLA and PRO, but lower for CHO. PRO and CHO increased insulin levels at 1h post-exercise, though both glucose and insulin were equal with PLA at 2h. Increased post-exercise ketone levels only occurred with PLA.Protein supplementation immediately post-exercise did not affect the doubling in whole body fat oxidation seen during a subsequent exercise trial 2 hours later. Neither did it affect resting fat oxidation during the post-exercise period despite increased insulin levels and attenuated ketosis. Carbohydrate intake dampened the increase in fat oxidation during the second test, though a significant increase was still observed compared to the first test.
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| 13. |
- Hansen, Mette, et al.
(författare)
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Effect of Whey Protein Hydrolysate on Performance and Recovery of Top-Class Orienteering Runners.
- 2015
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 25:2
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Tidskriftsartikel (refereegranskat)abstract
- This trial aimed to examine the effect of whey protein hydrolysate intake before and after exercise sessions on endurance performance and recovery in elite orienteers during a training camp. Eighteen elite orienteers participated in a randomized controlled intervention trial during a 1-week training camp (13 exercise sessions). Half of the runners (PRO-CHO) ingested a protein drink before (0.3 g kg−1) and a protein-carbohydrate drink after (0.3 g protein kg−1 and 1 g carbohydrate kg−1) each exercise session. The others ingested energy and timematched carbohydrate drinks (CHO). A 4-km run-test with 20 control points was performed before and on the last day of the intervention. Blood and saliva were obtained in the mornings, before and after run-tests, and after the last training session. During the intervention, questionnaires were fulfilled regarding psychological sense of performance capacity and motivation. PRO-CHO and not CHO improved performance in the 4-km run-test (interaction p < .05). An increase in serum creatine kinase was observed during the week, which was greater in CHO than PRO-CHO (interactionp < .01). Lactate dehydrogenase (p < .001) and cortisol (p = .057) increased during the week, but the change did not differ between groups. Reduction in sense of performance capacity during the intervention was greater in CHO (p < .05) than PRO-CHO. In conclusion, ingestion of whey protein hydrolysate before and after each exercise session improves performance and reduces markers of muscle damage during a strenuous 1-week training camp. The results indicate that protein supplementation in conjunction with each exercise session facilitates the recovery from strenuous training in elite orienteers.
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| 14. |
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| 15. |
- Melin, Anna K., Assistant Professor, 1965-, et al.
(författare)
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Disordered Eating and Eating Disorders in Aquatic Sports
- 2014
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 24:4, s. 450-459
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Tidskriftsartikel (refereegranskat)abstract
- Disordered eating behavior (DE) and eating disorders (EDs) are of great concern because of their associations with physical and mental health risks and, in the case of athletes, impaired performance. The syndrome originally known as the Female Athlete Triad, which focused on the interaction of energy availability, reproductive function, and bone health in female athletes, has recently been expanded to recognize that Relative Energy Deficiency in Sport (RED-S) has a broader range of negative effects on body systems with functional impairments in both male and female athletes. Athletes in leanness-demanding sports have an increased risk for RED-S and for developing EDs/DE. Special risk factors in aquatic sports related to weight and body composition management include the wearing of skimpy and tight-fitting bathing suits, and in the case of diving and synchronized swimming, the involvement of subjective judgments of performance. The reported prevalence of DE and EDs in athletic populations, including athletes from aquatic sports, ranges from 18 to 45% in female athletes and from 0 to 28% in male athletes. To prevent EDs, aquatic athletes should practice healthy eating behavior at all periods of development pathway, and coaches and members of the athletes' health care team should be able to recognize early symptoms indicating risk for energy deficiency, DE, and EDs. Coaches and leaders must accept that DE/EDs can be a problem in aquatic disciplines and that openness regarding this challenge is important.
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| 16. |
- Melin, Anna K., Assistant Professor, 1965-, et al.
(författare)
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Energy Availability in Athletics : Health, Performance, and Physique
- 2019
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Ingår i: International Journal of Sport Nutrition & Exercise Metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 29:2, s. 152-164
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Forskningsöversikt (refereegranskat)abstract
- The reported prevalence of low energy availability (LEA) in female and male track and field athletes is between 18% and 58% with the highest prevalence among athletes in endurance and jump events. In male athletes, LEA may result in reduced testosterone levels and libido along with impaired training capacity. In female track and field athletes, functional hypothalamic amenorrhea as consequence of LEA has been reported among 60% of elite middle- and long-distance athletes and 23% among elite sprinters. Health concerns with functional hypothalamic amenorrhea include impaired bone health, elevated risk for bone stress injury, and cardiovascular disease. Furthermore, LEA negatively affects recovery, muscle mass, neuromuscular function, and increases the risk of injuries and illness that may affect performance negatively. LEA in track and field athletes may occur due to intentional alterations in body mass or body composition, appetite changes, time constraints, or disordered eating behavior. Long-term LEA causes metabolic and physiological adaptations to prevent further weight loss, and athletes may therefore be weight stable yet have impaired physiological function secondary to LEA. Achieving or maintaining a lower body mass or fat levels through long-term LEA may therefore result in impaired health and performance as proposed in the Relative Energy Deficiency in Sport model. Preventive educational programs and screening to identify athletes with LEA are important for early intervention to prevent long-term secondary health consequences. Treatment for athletes is primarily to increase energy availability and often requires a team approach including a sport physician, sports dietitian, physiologist, and psychologist.
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| 17. |
- Mishima, T, et al.
(författare)
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Chicken breast attenuates high-intensity-exercise-induced decrease in rat sarcoplasmic reticulum Ca2+ handling
- 2008
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Ingår i: International journal of sport nutrition and exercise metabolism. - : Human Kinetics. - 1526-484X .- 1543-2742. ; 18:4, s. 399-411
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Tidskriftsartikel (refereegranskat)abstract
- This study was conducted to determine whether dietary chicken-breast extract (CBEX), a rich source of histidine-containing dipeptides, could modify exerciseinduced changes in sarcoplasmic reticulum (SR) function. After 5 weeks of dietary CBEX, SR Ca2+-handling ability was examined in the vastus lateralis muscles of rats subjected to high-intensity running for 2.5 min. Dietary CBEX caused an approximately 15% and 45% increase (p < .01) in muscle carnosine and anserine concentrations, respectively. In resting muscles, depressions in SR Ca2+–ATPase activity were evoked by dietary CBEX without concomitant changes in SR Ca2+ uptake and release rates. The data confirm that high-intensity exercise depresses SR Ca2+ handling. In spite of the same run time, SR Ca2+ handling was reduced to a lesser degree in muscles of CBEX-containing-chow-fed rats than in standard-chow-fed rats (p < .05). These results suggest that dietary CBEX might attenuate deteriorations in SR Ca2+-handling ability that occur with high-intensity exercise.
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| 18. |
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| 19. |
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| 20. |
- Pettersson, Stefan, 1972, et al.
(författare)
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Dietary Intake at Competition in Elite Olympic Combat Sports.
- 2014
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Ingår i: International journal of sport nutrition and exercise metabolism. - : Human Kinetics. - 1543-2742 .- 1526-484X. ; 24:1, s. 98-109
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the current study was to investigate elite female (n=21) and male (n=47) combat sports athletes' (n=68; mean age (± SD) 21.3 ± 3.8 years; mean height 177 ± 10.2 cm) dietary intake between weigh-in and the first bout in Olympic combat sports. The data were collected at 6 separate tournaments and measurements included estimated food records, time for recovery, and body weight (BW) at weigh-in and first match. In total, 33 athletes participated in wrestling and taekwondo, sports with extended recovery times, and 35 athletes in judo and boxing, sports with limited recovery time. The results displayed that despite a mean consumption of food and drinks corresponding to 4.2 kg, the athletes only regained an average of 1.9 kg BW during recovery. Water accounted for 86% of the total intake. For each litre of water consumed, athletes gained 0.57 kg BW, when excluding heavy weight athletes (n=5). Carbohydrate consumption was 5.5 g/kg BW, compared to the recommended 8-10 g/kg BW. In total, one-quarter of the consumed water originated from carbohydrate-rich drinks. Given the average recovery time of 18 (wrestling, taekwondo) versus 8 hours (judo, boxing), the former group consumed twice the amount of water, carbohydrates, protein, and fat as the latter group. In conclusion, a large proportion of the participants did not meet the recovery nutrition guidelines for carbohydrates. Also, the discrepancy between nutrient intake and weight gain points to the physiological barriers to retaining fluids during a limited recovery time after engaging in weight making practices.
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