Environmental intervention in a university canteen with focus on decision guidance: An evaluation study regarding food consumption, nutrient intake, perception, and satisfaction by canteen users.

Background: An environmental intervention with focus on Decision Guidance was implemented in a university canteen. It comprised the offer of a health promoting food option (HPFO), including a health promoting lunch option and health promoting snacks. Design and methods: Possible changes of food consumption and nutrient intake of student canteen users (substudy A), perception of the HPFO by canteen users (substudy B.1), and possible changes of their satisfaction regarding the canteen (substudy B.2) at least 10 weeks after the start of the intervention were examined. Substudy A used a controlled pretest-posttest-design (paired sample). The students were assigned to intervention group (canteen visits ≥ once/week, n = 27) or control group (canteen visits < once/week, n = 39). Substudy B.1 used a cross-sectional design, and substudy B.2 a pretest-posttest-design (paired sample). Only canteen users (≥once/week) were included (substudy B.1 n = 89, substudy B.2 n = 30). Results: Food consumption and nutrient intake did not change (p > 0.05) in the intervention group versus control group (substudy A). In substudy B.1 canteen users were aware of the HPFO, appreciated it highly, and were satisfied with it. In substudy B.2 canteen users were at posttest more satisfied regarding service and health value of offered lunches (p < 0.05). Conclusions: Although the HPFO was positively percepted, no effects on the daily diet were observed. The offered proportion of the HPFO should be increased.

Effects of internal cooling on physical performance, physiological and perceptional parameters when exercising in the heat: A systematic review with meta-analyses.

Background: An elevated core temperature (Tcore) increases the risk of performance impairments and heat-related illness. Internal cooling (IC) has the potential to lower Tcore when exercising in the heat. The aim of the review was to systematically analyze the effects of IC on performance, physiological, and perceptional parameters. Methods: A systematic literature search was performed in the PubMed database on 17 December 2021. Intervention studies were included assessing the effects of IC on performance, physiological, or perceptional outcomes. Data extraction and quality assessment were conducted for the included literature. The standardized mean differences (SMD) and 95% Confidence Intervals (CI) were calculated using the inverse-variance method and a random-effects model. Results: 47 intervention studies involving 486 active subjects (13.7% female; mean age 20-42 years) were included in the meta-analysis. IC resulted in significant positive effects on time to exhaustion [SMD (95% CI) 0.40 (0.13; 0.67), p < 0.01]. IC significantly reduced Tcore [-0.19 (22120.34; -0.05), p < 0.05], sweat rate [-0.20 (-0.34; -0.06), p < 0.01], thermal sensation [-0.17 (-0.33; -0.01), p < 0.05], whereas no effects were found on skin temperature, blood lactate, and thermal comfort (p > 0.05). IC resulted in a borderline significant reduction in time trial performance [0.31 (-0.60; -0.02), p = 0.06], heart rate [-0.13 (-0.27; 0.01), p = 0.06], rate of perceived exertion [-0.16 (-0.31; -0.00), p = 0.05] and borderline increased mean power output [0.22 (0.00; 0.44), p = 0.05]. Discussion: IC has the potential to affect endurance performance and selected physiological and perceptional parameters positively. However, its effectiveness depends on the method used and the time point of administration. Future research should confirm the laboratory-based results in the field setting and involve non-endurance activities and female athletes. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022336623.

[Consult Your Physician or Health Care Provider? Health and Legal Aspects Regarding the Use of Dietary Supplements Offered in the World Wide Web]. / Fragen Sie Ihren Arzt oder Apotheker? Gesundheitliche und juristische Aspekte des Konsums von Nahrungsergänzungsmitteln aus dem Internet.

BACKGROUND: In Germany, widespread use is made of dietary supplements (DS) to improve the individual health status, especially among patients diagnosed with certain conditions, elderly people and athletes. Legal aspects as well as health risks related to DS purchased via the internet are rarely analysed in Germany. PURPOSE: We aim to provide a review of the respective literature focusing on health risks, legal aspects und consumer information related to the internet retailing of DS. METHODS: A review of the literature including reference tracking was conducted between January 2017 and January 2018 and combined with the results of an analysis of legal regulations in Germany. RESULTS: Using the internet to research into health-related aspects is common among patients. However, this is often associated with a lack of individual and professional counselling regarding the potential risks and benefits of using DS. Potential side-effects are often not declared, and there is a high prevalence of contamination with harmful substances, especially among DS marketed as "natural health products". Athletes must be aware of the risk of being tested positive due to contamination of a DS with a WADA-banned substance. CONCLUSION: Questions regarding the use of DS in patients as well as in healthy athletes should be implemented into the medical history records by physicians. The use of DS should be carefully documented. A thorough cost-benefit analysis is recommended, and athletes should consider the risk of being tested positive.

Assessment of Dietary Intake of Long-Distance Race Car Drivers-A Pilot Study.

Long-distance race car drivers are classified as athletes. The sport is physically and mentally demanding, requiring long hours of practice. Therefore, optimal dietary intake is essential for health and performance of the athlete. The aim of the study was to evaluate dietary intake and to compare the data with dietary recommendations for athletes and for the general adult population according to the German Nutrition Society (DGE). A 24-h dietary recall during a competition preparation phase was obtained from 16 male race car drivers (28.3 ± 6.1 years, body mass index (BMI) of 22.9 ± 2.3 kg/m²). The mean intake of energy, nutrients, water and alcohol was recorded. The mean energy, vitamin B2, vitamin E, folate, fiber, calcium, water and alcohol intake were 2124 ± 814 kcal/day, 1.3 ± 0.5 mg/day, 12.5 ± 9.5 mg/day, 231.0 ± 90.9 ug/day, 21.4 ± 9.4 g/day, 1104 ± 764 mg/day, 3309 ± 1522 mL/day and 0.8 ± 2.5 mL/day respectively. Our study indicated that many of the nutrients studied, including energy and carbohydrate, were below the recommended dietary intake for both athletes and the DGE.

Influence of Obesity on Foot Loading Characteristics in Gait for Children Aged 1 to 12 Years.

BACKGROUND: Overweight and obesity are increasing health problems that are not restricted to adults only. Childhood obesity is associated with metabolic, psychological and musculoskeletal comorbidities. However, knowledge about the effect of obesity on the foot function across maturation is lacking. Decreased foot function with disproportional loading characteristics is expected for obese children. The aim of this study was to examine foot loading characteristics during gait of normal-weight, overweight and obese children aged 1-12 years. METHODS: A total of 10382 children aged one to twelve years were enrolled in the study. Finally, 7575 children (m/f: n = 3630/3945; 7.0±2.9 yr; 1.23±0.19 m; 26.6±10.6 kg; BMI: 17.1±2.4 kg/m2) were included for (complete case) data analysis. Children were categorized to normal-weight (≥3rd and <90th percentile; n = 6458), overweight (≥90rd and <97th percentile; n = 746) or obese (>97th percentile; n = 371) according to the German reference system that is based on age and gender-specific body mass indices (BMI). Plantar pressure measurements were assessed during gait on an instrumented walkway. Contact area, arch index (AI), peak pressure (PP) and force time integral (FTI) were calculated for the total, fore-, mid- and hindfoot. Data was analyzed descriptively (mean ± SD) followed by ANOVA/Welch-test (according to homogeneity of variances: yes/no) for group differences according to BMI categorization (normal-weight, overweight, obesity) and for each age group 1 to 12 yrs (post-hoc Tukey Kramer/Dunnett's C; α = 0.05). RESULTS: Mean walking velocity was 0.95 ± 0.25 m/s with no differences between normal-weight, overweight or obese children (p = 0.0841). Results show higher foot contact area, arch index, peak pressure and force time integral in overweight and obese children (p<0.001). Obese children showed the 1.48-fold (1 year-old) to 3.49-fold (10 year-old) midfoot loading (FTI) compared to normal-weight. CONCLUSION: Additional body mass leads to higher overall load, with disproportional impact on the midfoot area and longitudinal foot arch showing characteristic foot loading patterns. Already the feet of one and two year old children are significantly affected. Childhood overweight and obesity is not compensated by the musculoskeletal system. To avoid excessive foot loading with potential risk of discomfort or pain in childhood, prevention strategies should be developed and validated for children with a high body mass index and functional changes in the midfoot area. The presented plantar pressure values could additionally serve as reference data to identify suspicious foot loading patterns in children.

Reliability and day-to-day variability of peak fat oxidation during treadmill ergometry.

BACKGROUND: Exercising at intensities where fat oxidation rates are high has been shown to induce metabolic benefits in recreational and health-oriented sportsmen. The exercise intensity (Fatpeak) eliciting peak fat oxidation rates is therefore of particular interest when aiming to prescribe exercise for the purpose of fat oxidation and related metabolic effects. Although running and walking are feasible and popular among the target population, no reliable protocols are available to assess Fatpeak as well as its actual velocity (VPFO) during treadmill ergometry. Our purpose was therefore, to assess the reliability and day-to-day variability of VPFO and Fatpeak during treadmill ergometry running. METHODS: Sixteen recreational athletes (f = 7, m = 9; 25 ± 3 y; 1.76 ± 0.09 m; 68.3 ± 13.7 kg; 23.1 ± 2.9 kg/m(2)) performed 2 different running protocols on 3 different days with standardized nutrition the day before testing. At day 1, peak oxygen uptake (VO2peak) and the velocities at the aerobic threshold (VLT) and respiratory exchange ratio (RER) of 1.00 (VRER) were assessed. At days 2 and 3, subjects ran an identical submaximal incremental test (Fat-peak test) composed of a 10 min warm-up (70 % VLT) followed by 5 stages of 6 min with equal increments (stage 1 = VLT, stage 5 = VRER). Breath-by-breath gas exchange data was measured continuously and used to determine fat oxidation rates. A third order polynomial function was used to identify VPFO and subsequently Fatpeak. The reproducibility and variability of variables was verified with an intraclass correlation coefficient (ICC), Pearson's correlation coefficient, coefficient of variation (CV) and the mean differences (bias) ± 95 % limits of agreement (LoA). RESULTS: ICC, Pearson's correlation and CV for VPFO and Fatpeak were 0.98, 0.97, 5.0 %; and 0.90, 0.81, 7.0 %, respectively. Bias ± 95 % LoA was -0.3 ± 0.9 km/h for VPFO and -2 ± 8 % of VO2peak for Fatpeak. CONCLUSION: In summary, relative and absolute reliability indicators for VPFO and Fatpeak were found to be excellent. The observed LoA may now serve as a basis for future training prescriptions, although fat oxidation rates at prolonged exercise bouts at this intensity still need to be investigated.

Anthropometry and Dietary Intake before and during a Competition in Mountain Runners.

Mountain running is a non-Olympic sport consisting of uphill or up- and downhill races at moderate-to-high altitude. Special nutritional requirements are anticipated, but no nutritional data of mountain runners are available. In three studies, physique of elite and recreational athletes (N = 62), maximum oxygen uptake (N = 3), and prerace and race day dietary intake (N = 6) were measured (mean ± SD). Mean oxygen uptake was 68.7 ± 5.2 mL/kg/min. Energy and carbohydrate intake before a race (29 ± 15 km, 1596 ± 556 m HD) was 3199 ± 701 kcal/d (13.4 ± 2.9 MJ/d) and 497 ± 128 g/d (8.3 ± 1.8 g/kg/d) in German national team members. Fluid intake was calculated as 2783 ± 1543 mL/d. During the race, athletes consumed 336 ± 364 kcal and 927 ± 705 mL of fluids. Substrate intake per hour was calculated as 23 ± 22 g of carbohydrates and 4.0 ± 3.2 g of proteins. In conclusion, anthropometric and oxygen uptake characteristics of mountain runners were similar to those reported for elite distance runners. Carbohydrate intake before and during the race was below recommendations for endurance athletes. This is of concern when considering the increased reliance on carbohydrates at altitude.

Reliability of a Fully Automated Interpretation of γ -H2AX Foci in Lymphocytes of Moderately Trained Subjects under Resting Conditions.

Background. Analysis of γ-H2AX foci is a promising approach to evaluate exercise-induced DNA damage. However, baseline levels and day-to-day variability of γ-H2AX foci have not been investigated in healthy subjects at rest. Methods. Blood was taken from eight moderately trained healthy males (29 ± 3 yrs, 1.84 ± 0.03 m, and 85 ± 6 kg) at two separate days (M1/M2) after 24-hour exercise cessation. Number of γ-H2AX foci per 100 lymphocytes (N), number of foci per affected lymphocyte (NAL), percentage of affected lymphocytes (PAL), and diameter (D) of γ-H2AX foci were analyzed (mean ± SD). Differences between M1 and M2 were analyzed using paired t-tests (α = 0.05). Day-to-day variability was evaluated by calculating the coefficients of variation (CV%), bias, and limits of agreement (LoA). Results. There were no statistically significant differences between M1 (N: 7.6 ± 4.4, NAL: 1.2 ± 0.2, PAL: 5.9 ± 2.6%, and D: 0.63 ± 0.07) and M2 (N: 8.4 ± 4.6, NAL: 1.3 ± 0.1, PAL: 6.9 ± 4.2%, and D: 0.66 ± 0.06). CV was calculated to be 98.5% (N), 88.9% (PAL), 11.3% (NAL), and 8.0% (D). Bias (LoA) was 0.75 (-15.2/13.7), -0.02 (-0.36/0.33), -1.0 (-11.9/9.9), and -0.04 (-0.16/0.09), respectively. Conclusions. Background level in healthy subjects is approximately 0.07 to 0.09 γ-H2AX foci/cell. NAL and D are reliable measures.

Can more than one incremental cycling test be performed within one day?

Changes in performance parameters over four consecutive maximal incremental cycling tests were investigated to determine how many tests can be performed within one single day without negatively affecting performance. Sixteen male and female subjects (eight trained (T): 25 ± 3 yr, BMI 22.6 ± 2.5 kg·m(-2), maximal power output (P(max)) 4.6 ± 0.5 W·kg(-1); eight untrained (UT): 27 ± 3 yr, BMI 22.3 ± 1.2 kg·m(-2), P(max) 2.9 ± 0.3 W·kg(-1)) performed four successive maximal incremental cycling tests separated by 1.5 h of passive rest. Individual energy requirements were covered by standardised meals between trials. Maximal oxygen uptake (VO(2max)) remained unchanged over the four tests in both groups (P = 0.20 and P = 0.33, respectively). P(max) did not change in the T group (P = 0.32), but decreased from the third test in the UT group (P < 0.01). Heart rate responses to submaximal exercise were elevated from the third test in the T group and from the second test in the UT group (P < 0.05). The increase in blood lactate shifted rightward over the four tests in both groups (P < 0.001 and P < 0.01, respectively). Exercise-induced net increases in epinephrine and norepinephrine were not different between the tests in either group (P ≥ 0.15). If VO(2max) is the main parameter of interest, trained and untrained individuals can perform at least four maximal incremental cycling tests per day. However, because other parameters changed after the first and second test, respectively, no more than one test per day should be performed if parameters other than VO(2max) are the prime focus.

Carbohydrate intake and food sources of junior triathletes during a moderate and an intensive training period.

The study was conducted to investigate the quantity and the main food sources of carbohydrate (CHO) intake of junior elite triathletes during a short-term moderate (MOD; 12 km swimming, 100 km cycling, 30 km running per wk) and intensive training period (INT; 23 km swimming, 200 km cycling, 45 km running per wk). Self-reported dietary-intake data accompanied by training protocols of 7 male triathletes (18.1 ± 2.4 yr, 20.9 ± 1.4 kg/m(2)) were collected on 7 consecutive days during both training periods in the same competitive season. Total energy and CHO intake were calculated based on the German Food Database. A paired t test was applied to test for differences between the training phases (α = .05). CHO intake was slightly higher in INT than in MOD (9.0 ± 1.6 g · kg(-1) · d(-1) vs. 7.8 ± 1.6 g · kg(-1) · d(-1); p = .041). Additional CHO in INT was mainly ingested during breakfast (115 ± 37 g in MOD vs. 175 ± 23 g in INT; p = .002) and provided by beverages (280.5 ± 97.3 g/d vs. 174.0 ± 58.3 g/d CHO; p = .112). Altogether, main meals provided approximately two thirds of the total CHO intake. Pre- and postexercise snacks additionally supplied remarkable amounts of CHO (198.3 ± 84.3 g/d in INT vs. 185.9 ± 112 g/d CHO in MOD; p = .231). In conclusion, male German junior triathletes consume CHO in amounts currently recommended for endurance athletes during moderate to intensive training periods. Main meals provide the majority of CHO and should therefore not be skipped. CHO-containing beverages, as well as pre- and postexercise snacks, may provide a substantial amount of CHO intake in training periods with high CHO requirements.

Medical results of preparticipation examination in adolescent athletes.

BACKGROUND: Preparticipation examinations (PPE) are frequently used to evaluate eligibility for competitive sports in adolescent athletes. Nevertheless, the effectiveness of these examinations is under debate since costs are high and its validity is discussed controversial. PURPOSE: To analyse medical findings and consequences in adolescent athletes prior to admission to a sports school. METHODS: In 733 adolescent athletes (318 girls, 415 boys, age 12.3±0.4, 16 sports disciplines), history and clinical examination (musculoskeletal, cardiovascular, general medicine) was performed to evaluate eligibility. PPE was completed by determination of blood parameters, ECG at rest and during ergometry, echocardiography and x-rays and ultrasonography if indicated. Eligibility was either approved or rated with restriction. Recommendations for therapy and/or prevention were given to the athletes and their parents. Results Historical (h) and clinical (c) findings (eg, pain, verified pathologies) were more frequent regarding the musculoskeletal system (h:120, 16.4%; c:247, 33.7%) compared to cardiovascular (h:9, 1.2%; c:23, 3.1%) or general medicine findings (h:116, 15.8%; c:71, 9.7%). ECG at rest was moderately abnormal in 46 (6.3%) and severely abnormal in 25 athletes (3.4%). Exercise ECG was suspicious in 25 athletes (3.4%). Relevant echocardiographic abnormalities were found in 17 athletes (2.3%). In 52 of 358 cases (14.5%), x-rays led to diagnosis (eg, Spondylolisthesis). Eligibility was temporarily restricted in 41 athletes (5.6%). Three athletes (0.4%) had to be excluded from competitive sports. Therapy (eg, physiotherapy, medication) and/or prevention (sensorimotor training, vaccination) recommendations were deduced due to musculoskeletal (t:n=76,10.3%;p: n=71,9.8%) and general medicine findings (t:n=80, 10.9%; p:n=104, 14.1%). CONCLUSION: Eligibility for competitive sports is restricted in only 5.5% of adolescent athletes at age 12. Eligibility refusals are rare. However, recommendations for therapy and prevention are frequent, mainly regarding the musculoskeletal system. In spite of time and cost consumption, adolescent preparticipation before entering a career in high-performance sports is supported.

Static and dynamic foot characteristics in children aged 1-13 years: a cross-sectional study.

The aim of this study was to acquire static and dynamic foot geometry and loading in childhood, and to establish data for age groups of a population of 1-13 year old infants and children. A total of 10,382 children were recruited and 7788 children (48% males and 52% females) were finally included into the data analysis. For static foot geometry foot length and foot width were quantified in a standing position. Dynamic foot geometry and loading were assessed during walking on a walkway with self selected speed (Novel Emed X, 100Hz, 4 sensors/cm(2)). Contact area (CA), peak pressure (PP), force time integral (FTI) and the arch index were calculated for the total, fore-, mid- and hindfoot. Results show that most static and dynamic foot characteristics change continuously during growth and maturation. Static foot length and width increased with age from 13.1±0.8cm (length) and 5.7±0.4cm (width) in the youngest to 24.4±1.5cm (length) and 8.9±0.6cm (width) in the oldest. A mean walking velocity of 0.94±0.25m/s was observed. Arch-index ranged from 0.32±0.04 [a.u.] in the one-year old to 0.21±0.13 [a.u.] in the 5-year olds and remains constant afterwards. This study provides data for static and dynamic foot characteristics in children based on a cohort of 7788 subjects. Static and dynamic foot measures change differently during growth and maturation. Dynamic foot measurements provide additional information about the children's foot compared to static measures.

Resting metabolic rate in elite rowers and canoeists: difference between indirect calorimetry and prediction.

BACKGROUND: Athletes may differ in their resting metabolic rate (RMR) from the general population. However, to estimate the RMR in athletes, prediction equations that have not been validated in athletes are often used. The purpose of this study was therefore to verify the applicability of commonly used RMR predictions for use in athletes. METHODS: The RMR was measured by indirect calorimetry in 17 highly trained rowers and canoeists of the German national teams (BMI 24 ± 2 kg/m(2), fat-free mass 69 ± 15 kg). In addition, the RMR was predicted using Cunningham (CUN) and Harris-Benedict (HB) equations. A two-way repeated measures ANOVA was calculated to test for differences between predicted and measured RMR (α = 0.05). The root mean square percentage error (RMSPE) was calculated and the Bland-Altman procedure was used to quantify the bias for each prediction. RESULTS: Prediction equations significantly underestimated the RMR in males (p < 0.001). The RMSPE was calculated to be 18.4% (CUN) and 20.9% (HB) in the entire group. The bias was 133 kcal/24 h for CUN and 202 kcal/24 h for HB. CONCLUSIONS: Predictions significantly underestimate the RMR in male heavyweight endurance athletes but not in females. In athletes with a high fat-free mass, prediction equations might therefore not be applicable to estimate energy requirements. Instead, measurement of the resting energy expenditure or specific prediction equations might be needed for the individual heavyweight athlete.

The intensity and effects of strength training in the elderly.

BACKGROUND: The elderly need strength training more and more as they grow older to stay mobile for their everyday activities. The goal of training is to reduce the loss of muscle mass and the resulting loss of motor function. The dose-response relationship of training intensity to training effect has not yet been fully elucidated. METHODS: PubMed was selectively searched for articles that appeared in the past 5 years about the effects and dose-response relationship of strength training in the elderly. RESULTS: Strength training in the elderly (>60 years) increases muscle strength by increasing muscle mass, and by improving the recruitment of motor units, and increasing their firing rate. Muscle mass can be increased through training at an intensity corresponding to 60% to 85% of the individual maximum voluntary strength. Improving the rate of force development requires training at a higher intensity (above 85%), in the elderly just as in younger persons. It is now recommended that healthy old people should train 3 or 4 times weekly for the best results; persons with poor performance at the outset can achieve improvement even with less frequent training. Side effects are rare. CONCLUSION: Progressive strength training in the elderly is efficient, even with higher intensities, to reduce sarcopenia, and to retain motor function.

Physical activity levels to estimate the energy requirement of adolescent athletes.

Adequate energy intake in adolescent athletes is considered important. Total energy expenditure (TEE) can be calculated from resting energy expenditure (REE) and physical activity level (PAL). However, validated PAL recommendations are available for adult athletes only. Purpose was to comprise physical activity data in adolescent athletes and to establish PAL recommendations for this population. In 64 competitive athletes (15.3 ± 1.5 yr, 20.5 ± 2.0 kg/m2) and 14 controls (15.1 ± 1.1 yr, 21 ± 2.1 kg/m2) TEE was calculated using 7-day activity protocols validated against doubly-labeled water. REE was estimated by Schofield-HW equation, and PAL was calculated as TEE:REE. Observed PAL in adolescent athletes (1.90 ± 0.35) did not differ compared with controls (1.84 ± 0.32, p = .582) and was lower than recommended for adult athletes by the WHO. In conclusion, applicability of PAL values recommended for adult athletes to estimate energy requirements in adolescent athletes must be questioned. Instead, a PAL range of 1.75-2.05 is suggested.

How to test maximal oxygen uptake: a study on timing and testing procedure of a supramaximal verification test.

Verification tests are becoming increasingly common for confirming maximal oxygen uptake (VO2 max) attainment. Yet, timing and testing procedures vary between working groups. The aims of this study were to investigate whether verification tests can be performed after an incremental test or should be performed on a separate day, and whether VO2 max can still be determined within the first testing session in subjects not satisfying the verification criterion. Forty subjects (age, 24 ± 4 years; VO2 max, 50 ± 7 mL·min-1·kg-1) performed a maximal incremental treadmill test and, 10 min afterwards, a verification test (VerifDay1) at 110% of maximal velocity (vmax). The verification criterion was a VerifDay1 peak oxygen uptake (VO2 peak) ≤5.5% higher than the incremental test value. Subjects not achieving the verification criterion performed another verification test at 115% vmax (VerifDay1') 10 min later, trying to confirm VerifDay1 VO2 peak as VO2 max. All other subjects exclusively repeated VerifDay1 on a separate day (VerifDay2). Of the 40 subjects, 6 did not satisfy the verification criterion. In 4 of them, attainment of VO2 max was confirmed by VerifDay1'. VO2 peak was equivalent between VerifDay1 and VerifDay2 (3722 ± 991 mL·min-1 vs. 3752 ± 995 mL·min-1, p = 0.56), whereas time to exhaustion was significantly longer in VerifDay2 (2:06 ± 0:22 min:s vs. 2:42 ± 0:38 min:s, p < 0.001, n = 34). The verification test VO2 peak does not seem to be affected by a preceding maximal incremental test. Incremental and verification tests can therefore be performed within the same testing session. In individuals not achieving the verification criterion, VO2 max can be determined by means of a subsequent, more intense verification test in most but not all cases.

How much is too much? A case report of nutritional supplement use of a high-performance athlete.

Although dietary nutrient intake is often adequate, nutritional supplement use is common among elite athletes. However, high-dose supplements or the use of multiple supplements may exceed the recommended daily allowance (RDA) of particular nutrients or even result in a daily intake above tolerable upper limits (UL). The present case report presents nutritional intake data and supplement use of a highly trained male swimmer competing at international level. Habitual energy and micronutrient intake were analysed by 3 d dietary reports. Supplement use and dosage were assessed, and total amount of nutrient supply was calculated. Micronutrient intake was evaluated based on RDA and UL as presented by the European Scientific Committee on Food, and maximum permitted levels in supplements (MPL) are given. The athlete's diet provided adequate micronutrient content well above RDA except for vitamin D. Simultaneous use of ten different supplements was reported, resulting in excess intake above tolerable UL for folate, vitamin E and Zn. Additionally, daily supplement dosage was considerably above MPL for nine micronutrients consumed as artificial products. Risks and possible side effects of exceeding UL by the athlete are discussed. Athletes with high energy intake may be at risk of exceeding UL of particular nutrients if multiple supplements are added. Therefore, dietary counselling of athletes should include assessment of habitual diet and nutritional supplement intake. Educating athletes to balance their diets instead of taking supplements might be prudent to prevent health risks that may occur with long-term excess nutrient intake.

Physical activity, antioxidant status, and protein modification in adolescent athletes.

UNLABELLED: Exercise may increase reactive oxygen species production, which might impair cell integrity and contractile function of muscle cells. However, little is known about the effect of regular exercise on the antioxidant status of adolescents. PURPOSE: This study aimed to evaluate the impact of exercise on the antioxidant status and protein modifications in adolescent athletes. METHODS: In 90 athletes and 18 controls (16 +/- 2 yr), exercise-related energy expenditure was calculated on the basis of a 7-d activity protocol. Antioxidant intake and plasma concentrations of alpha-tocopherol, carotenoids, and uric acid were analyzed. Plasma antioxidant activity was determined by Trolox equivalent (TE) antioxidant capacity and electron spin resonance spectrometry. Protein modifications were assessed with structural changes of transthyretin using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Data were analyzed by two-way ANOVA and post hoc by the Tukey-Kramer test (alpha = 0.05). RESULTS: Antioxidant intake correlated with energy intake and was within the recommended daily allowance for vitamins C and E and beta-carotene. Plasma levels of neither nutritional antioxidants nor uric acid differed between the groups. TE antioxidant capacity was higher in athletes (men = 1.47 +/- 0.2 mmol TE per liter, women = 1.45 +/- 0.2 mmol TE per liter) compared with controls (men = 1.17 +/- 0.04 mmol TE per liter, women = 1.14 +/- 0.04 mmol TE per liter) and increased with exercise-related energy expenditure (P = 0.007). Transthyretin cysteinylation rate differed between the groups, with the highest rate of protein modifications in moderately active subjects (P = 0.007). CONCLUSIONS: Results suggest that if the nutritional choice of athletes is well balanced, enough antioxidants are provided to meet recommended amounts. Moreover, regular exercise increases blood antioxidant capacity in young athletes, whereas chronic exercise was not shown to promote protein modifications. Thus, in young athletes who are sufficiently supplied with antioxidants, beneficial effects of exercise on antioxidant status rather than on oxidative stress may be anticipated.

Exercise increases the plasma antioxidant capacity of adolescent athletes.

BACKGROUND: The reactive oxygen species produced as a result of exercise might exceed an individual's antioxidant defence system. Various endogenous antioxidants are elevated in adult athletes, resulting in an improved antioxidant capacity. However, little is known about antioxidant defence in adolescents. The purpose of this study was to examine presumed adaptations of antioxidant capacity in exercising adolescents. METHODS: Trolox-equivalent antioxidant capacity (TEAC), uric acid and nutritional antioxidants were measured in the plasma of 91 male and 98 female athletes (mean age 15.9 +/- 2.0 years) and compared to those of 18 male and 22 female sedentary controls (mean age 16.3 +/- 2.1 years). Antioxidant intake was calculated using 4-day dietary records. RESULTS: Neither male nor female athletes showed differences in alpha-tocopherol, beta-carotene or ascorbate intake compared to controls. Plasma levels of alpha-tocopherol and carotenoids in athletes and controls did not differ either. Nevertheless, athletes of both sexes had higher TEAC values than their respective controls (male athletes 1.48 +/- 0.22 mmol/l vs. male controls 1.23 +/- 0.19 mmol/l, female athletes 1.47 +/- 0.20 mmol/l vs. female controls 1.15 +/- 0.04 mmol/l, p < 0.05). CONCLUSIONS: Regular exercise enhances antioxidant capacity in adolescent athletes, independently of their dietary antioxidant intake, which indicates activity-related adaptations.

Consumption of soy isoflavones does not affect plasma total homocysteine or asymmetric dimethylarginine concentrations in healthy postmenopausal women.

Postmenopausal women are at increased risk for cardiovascular disease because many risk factors are aggravated by menopause. Phytoestrogens may modulate risk factors favorably, involving mechanisms similar to estrogen. The effect of phytoestrogens on the atherogenic amino acids homocysteine and asymmetric dimethylarginine (ADMA) was investigated in a controlled intervention study in healthy postmenopausal women. A multicenter, double-blind, crossover intervention trial in 89 postmenopausal women from Denmark, Germany, and the UK was performed. Subjects consumed fruit cereal bars with or without soy isoflavones (50 mg/d) for 8 wk each with an 8-wk washout period in between. Urinary phytoestrogens increased significantly after isoflavone intervention (P < 0.001). Isoflavone supplementation did not affect plasma total homocysteine or ADMA. For homocysteine, changes from baseline were 0.32 micromol/L (range: -0.31-0.92; 95% CI 0.13-0.72), and 0.29 micromol/L (range: -0.45-1.09; 95% CI 0.01-0.63, P = 0.286) for isoflavone treatment and placebo, respectively. For ADMA concentrations, changes from baseline were -0.02 micromol/L (range: -0.08-0.03; 95% CI -0.04-0.01, and 0.00 micromol/L (range: -0.05-0.03; 95% CI -0.03-0.01, P = 0.397) for isoflavone treatment and placebo, respectively. There was no association between plasma total homocysteine and ADMA. Changes from baseline in plasma ADMA and folate were negatively correlated (r = -0.18, P = 0.017). These results challenge the overall health effect of isoflavone supplementation in healthy postmenopausal women.