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Trace Mineral Requirements for Athletes

Priscilla M. Clarkson and Emily M. Haymes

This paper reviews information pertaining to zinc, copper, chromium, and selenium requirements of athletes. Exercise increases zinc loss from the body, and dietary intake for some athletes, especially females, may be inadequate. Blood copper levels are altered by exercise, but there is no information to suggest that copper ingestion or status is compromised in athletes. Studies have shown that urinary chromium excretion is increased by exercise, but whether this leads to an increased requirement is still unknown. There is concern that athletes may not ingest sufficient quantities of chromium; however, there are inadequate data to confirm this. The limited data that exist show that athletes do not have altered selenium status. There is no conclusive evidence that supplementation with any of these trace minerals will enhance performance. A diet containing foods rich in micronutrients is recommended. However, for those athletes concerned that their diets may not be sufficient, a multivitamin/ mineral supplement containing no more than the RDA may be advised.

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Effect of the Joint Administration of Selenium and Vitamin E in Combination with Regular Aerobic Exercise on Markers of Lipid Peroxidation and Glutathione Peroxidase in Diabetic Rats

Hyun-Tae Kim

We investigated the effect of long-term treatment (6 wk) with selenium and vitamin E, in combination with aerobic exercise training, on malondialdehyde (MDA), oxidized low-density lipoprotein (ox-LDL), and glutathione peroxi-dase (GPx) in STZ-induced diabetic rats. The rats were assigned randomly to one of three treatment groups (n = 12 per group): 1) exercise group (EX), 2) selenium/vitamin E/exercise group (SVE), and 3) selenium/vitamin E group (SV). To estimate the acute effect of exercise, a 30-min endurance exercise was used. The MDA concentration was significantly lower in the SVE. The ox-LDL was significantly lower in the SVE and SV. The hepatic concentrations of selenium and vitamin E were significantly higher in the SVE. These results indicate that the increase in MDA is mildly attenuated in rats that were aerobically trained. Moreover, the joint administration of selenium and vitamin E with or without exercise training reduces the levels of ox-LDL.

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Free Radicals, Exercise, and Antioxidant Supplementation

Mitchell M. Kanter

Free radicals have been implicated in the development of diverse diseases such as cancer, diabetes, and cataracts, and recent epidemic-logical data suggest an inverse relationship between antioxidant intake and cardiovascular disease risk. Data also suggest that antioxidants may delay aging, Research has indicated that free radical production and subsequent lipid peroxidation are normal sequelae to the rise in oxygen consumption with exercise. Consequently, antioxidant supplementation may detoxify the peroxides produced during exercise and diminish muscle damage and soreness. Vitamin E, beta carotene, and vitamin C have shown promise as protective antioxidants. Other ingestible products with antioxidant properties include selenium and coenzyme Q 10 . The role (if any) that free radicals play in the development of exercise-induced tissue damage, or the protective role that antioxidants may play, remains to be elucidated. Current methods used to assess exercise-induced lipid peroxidation are not extremely specific or sensitive; research that utilizes more sophisticated methodologies should help to answer many questions regarding dietary antioxidants.

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Altered Antioxidant and Trace-Element Status in Adolescent Female Gymnasts

Eyad Alshammari, Shahida Shafi, Jaana Nurmi-Lawton, Andrew Taylor, Susan Lanham-New, and Gordon Ferns

Physical activity is associated with the generation of reactive oxygen species and may lead to decreased levels of plasma antioxidants and increased oxidant stress. Some studies have reported that antioxidant supplements can reduce the consequences of oxidative stress during exercise. In this study the authors aimed to assess the chronic effects of exercise on endogenous serum antioxidant enzyme concentrations. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity were measured in adolescent girls who were either competitive gymnasts or sedentary controls. The relationship between age, body-mass index, dietary intake, trace-element status, and serum GPx and SOD was determined. The participants in the study were part of a 3-yr longitudinal investigation of exercise and peak bone-mass development in 38 competitive gymnasts and 40 healthy sedentary adolescent females 8–17 yr of age. Serum GPx and SOD were measured using colorimetric assays, and trace elements were measured using inductively coupled plasma mass spectrometry. The mean serum GPx concentrations were significantly higher in the gymnasts than in the sedentary females (157 ± 11.1 vs. 126 ± 8.8 U/ml, p < .05). In contrast, serum SOD concentrations were significantly lower in the gymnasts than in the sedentary group (7.24 ± 2.6 vs. 8.57 ± 2.3 U/ml, p < .05). Serum selenium, zinc, and copper were higher in the physically active group than in the inactive group (0.89 ± 0.03, 10.86 ± 0.39, 14.50 ± 0.50 vs. 0.81 ± 0.03, 10.32 ± 0.28, and 14.38 ± 0.42 μmol/L, respectively), although only serum selenium reached statistical significance (p < .05). The findings show that young female gymnasts have an altered antioxidant enzyme profile compared with their less physically active peers.

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Exercise and Mononuclear Cell DNA Damage: The Effects of Antioxidant Supplementation

G.W. Davison, C.M. Hughes, and R.A. Bell

The purpose of this investigation was to determine the effects of antioxidant supplementation on DNA damage following exercise. Fourteen subjects were randomly assigned to one of two groups and required to ingest either antioxidants (400 mg α-lipoic acid, 200 mg co-enzyme Q10, 12 mg manganese, 600 mg vitamin C, 800 mg N-acetyl cysteine, 400 μg selenium, and 400 IU α-tocopherol per day) or placebos for 7 d. Exercise increased DNA damage, PS, FRAP, and LDH (P < 0.05), but not selectively between groups. LDH and PS concentration decreased 1 h post-exercise (P < 0.05), while LH concentration decreased 1 h post-exercise in the antioxidant group only (P < 0.05). The antioxidant group had a higher concentration of LH (P < 0.05), perhaps due to a selective difference between groups post-exercise (P < 0.05). The main findings of this investigation demonstrate that exhaustive aerobic exercise induces DNA damage, while anti-oxidant supplementation does not protect against damage.

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Effects of Antioxidant Supplementation on Exercise Performance in Acute Normobaric Hypoxia

Christian Mariacher, Hannes Gatterer, Joachim Greilberger, Radoslav Djukic, Michaela Greilberger, Marc Philippe, and Martin Burtscher

Background/Objectives:

To compare the effects of a 3-week supplementation between two different mixtures of antioxidants and placebo on aerobic exercise performance in acute normobaric hypoxia.

Subjects/Methods:

Seventeen subjects were randomly assigned in a double-blind fashion to receive a broad-based antioxidants supplement containing beta-carotene, ascorbic acid, d-alpha-tocopherol-succinate, N-acetylcysteine, riboflavin, zinc, and selenium (antioxidant capsule group [AO group]), or a combination of alpha-ketoglutaric acid (α-KG) and 5-hydroxymethylfurfural (5-HMF; CYL concentrate supplementation group [CS group]), or placebo (PL group). Before and after supplementation, subjects performed two incremental cycle-exercise tests until exhaustion. The first test was conducted under normoxic conditions (LA, FiO2 of 20.9%, ~547 m) and the second after the 3-week supplementation period under normobaric hypoxic conditions (AHA, FiO2 of 12.9%, ~4300m).

Results:

In CS peak cycling performance (peak power) declined from LA to AHA 7.3% (90% CI: 2.2–12.4) less compared with PL (p = .04) and 6.7% (90%CI: 3.2–10.2) less compared with AO (p = .03). Better maintenance of aerobic exercise capacity in CS was associated with an attenuated reduction in maximal heart rate in hypoxia.

Conclusions:

Aerobic exercise performance was less impaired in acute normobaric hypoxia after 3 weeks with supplementation of α-KG and 5-HMF compared with a broad-based antioxidants supplement or PL.

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Increased Lipid Peroxidation in Trained Men after 2 Weeks of Antioxidant Supplementation

Manfred Lamprecht, Peter Hofmann, Joachim F. Greilberger, and Guenther Schwaberger

Purpose:

To assess the effects of an encapsulated antioxidant concentrate (EAC) and exercise on lipid peroxidation (LIPOX) and the plasma antioxidant enzyme glutathione peroxidase (Pl-GPx).

Methods:

Eight trained male cyclists (VO2max > 55 ml · kg−1 · min−1) participated in this randomized, placebo-controlled, double-blinded, crossover study and undertook 4 cycle-ergometer bouts: 2 moderate exercise bouts over 90 min at 45% of individual VO2max and 2 strenuous exercise bouts at 75% of individual VO2max for 30 min. The first 2 exercise tests—1 moderate and 1 strenuous—were conducted after 4 weeks wash-out and after 12 and 14 days of EAC (107 IU vitamin E, 450 mg vitamin C, 36 mg β-carotene, 100 μg selenium) or placebo treatment. After another 4 weeks wash-out, participants were given the opposite capsule treatment and repeated the 2 exercise tests. Physical exercise training was equal across the whole study period, and nutrition was standardized by a menu plan the week before the tests. Blood was collected before exercise, immediately postexercise, and 30 min and 60 min after each test. Plasma samples were analyzed for LIPOX marker malondialdehyde (MDA) and the antioxidant enzyme pl-GPx.

Results:

MDA concentrations were significantly increased after EAC supplementation at rest before exercise and after moderate exercise (p < .05). MDA concentrations showed no differences between treatments after strenuous exercise (p > .1). Pl-GPx concentrations decreased at all time points of measurement after EAC treatment (p < .05).

Conclusions:

The EAC induced an increase of LIPOX as indicated by MDA and decreased pl-GPx concentrations pre- and postexercise.

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Dietary Intake, Anthropometric Characteristics, and Iron and Vitamin D Status of Female Adolescent Ballet Dancers Living in New Zealand

Kathryn L. Beck, Sarah Mitchell, Andrew Foskett, Cathryn A Conlon, and Pamela R. Von Hurst

Ballet dancing is a multifaceted activity requiring muscular power, strength, endurance, flexibility, and agility; necessitating demanding training schedules. Furthermore dancers may be under aesthetic pressure to maintain a lean physique, and adolescent dancers require extra nutrients for growth and development. This cross-sectional study investigated the nutritional status of 47 female adolescent ballet dancers (13–18 years) living in Auckland, New Zealand. Participants who danced at least 1 hr per day 5 days per week completed a 4-day estimated food record, anthropometric measurements (Dual-energy X-ray Absorptiometry) and hematological analysis (iron and vitamin D). Mean BMI was 19.7 ± 2.4kg/m2 and percentage body fat, 23.5 ± 4.1%. The majority (89.4%) of dancers had a healthy weight (5th-85th percentile) using BMI-for-age growth charts. Food records showed a mean energy intake of 8097.3 ± 2155.6kJ/day (48.9% carbohydrate, 16.9% protein, 33.8% fat, 14.0% saturated fat). Mean carbohydrate and protein intakes were 4.8 ± 1.4 and 1.6 ± 0.5g/kg/day respectively. Over half (54.8%) of dancers consumed less than 5g carbohydrate/kg/day, and 10 (23.8%) less than 1.2 g protein/kg/day. Over 60% consumed less than the estimated average requirement for calcium, folate, magnesium and selenium. Thirteen (28.3%) dancers had suboptimal iron status (serum ferritin (SF) <20μg/L). Of these, four had iron deficiency (SF < 12μg/L, hemoglobin (Hb) ≥ 120g/L) and one iron deficiency anemia (SF < 12μg/L, Hb < 120g/L). Mean serum 25-hydroxy vitamin D was 75.1 ± 18.6nmol/L, 41 (91.1%) had concentrations above 50nmol/L. Female adolescent ballet dancers are at risk for iron deficiency, and possibly inadequate nutrient intakes.

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Abstracts From the December 2019 International Sport + Exercise Nutrition Conference in Newscastle upon Tyne

-year case report JL Areta 2. Dietary selenium intakes and their association with muscle strength and function in ≥85 year old adults: the Newcastle 85+ Study G Perri, T Hill, J Mathers, N Mendonça 3. Treatment strategies to reverse bone loss in athletes with functional hypothalamic amenorrhea J Hamer

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Awareness and Attitude Toward Use of Dietary Supplements and the Perceived Outcomes Among Saudi Adult Male Members of Fitness Centers in Saudi Arabia

Hanan A. Alfawaz, Soundararajan Krishnaswamy, Latifah Al-Faifi, Halima Ali Bin Atta, Mohammad Al-Shayaa, Saad A. Alghanim, and Nasser M. Al-Daghri

vitamin D, folic acid, and selenium, have reduced the fear of negative outcomes from dietary supplements and, hence, is also a reason for their common consumption ( Berendsen et al., 2016 ). Even though the popularity of dietary supplements is high and expected to continue to increase worldwide, studies