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Copper Status of Collegiate Female Athletes Involved in Different Sports

Sareen S. Gropper, L. Michelle Sorrels, and Daniel Blessing

Copper status was assessed in 70 female collegiate athletes aged 18 to 25 years participating in cross country track, tennis, softball, swimming, soccer, basketball, and gymnastics during the 2000–2001 season. A group of 8 college-aged females, 20 to 23 years of age, who were not collegiate athletes, served as controls. Mean copper intakes including supplements did not differ significantly among the controls and athletic teams. Mean copper intakes including supplements as micrograms/day and percent recommended dietary allowance (RDA) were as follows: controls 1071 ± 772 μg (119 ± 86%), cross country track 1468 ± 851 μg (163 ± 95%), tennis 1099 ± 856 μg (122 ± 95%), softball 654 ± 420 μg (73 ± 47%), swimming 1351 ± 1060 μg (150 ± 118%), soccer 695 ± 368 μg (77 ± 41%), and gymnastics 940 ± 863 μg (104 ± 96%). Forty-one percent of athletes and 29% of controls failed to consume two thirds of the RDA for copper. Mean serum copper and ceruloplasmin concentrations were within the normal range and did not differ significantly among the controls (117 ± 22 μg/dl, 445 ± 122 μg/L) and cross country track (98 ± 17 μg/dl, 312 ± 59 μg/L), tennis (140 ± 84 μg/dl, 424 ± 244 μg/L), softball (95 ± 30 μg/dl, 310 ± 77 μg/L), swimming (98 ± 25 μg/dl, 312 ± 40 μg/L), soccer (93 ± 15 μg/dl, 324 ± 54 μg/ L), basketball (85 ± 10 μg/dl, 280 ± 62 μg/L), and gymnastics (96 ± 21 μg/dl, 315 ± 68 μg/L) teams. Copper status of female collegiate athletes appears to be adequate in this cross-sectional assessment.

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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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Magnesium, Zinc, and Copper Status in Women Involved in Different Sports

Ramón J. Nuviala, María G. Lapieza, and Enrique Bernal

The dietary intake, serum levels, and urinary excretion of magnesium, zinc, and copper were studied in 78 women involved in different sports (karate, handball, basketball, and running) and in 65 sedentary women. Seven-day, weighed-food dietary reports revealed that no group of female athletes reached the minimal intake recommended for magnesium (280 mg/day) and zinc (12 mg/day), although their values were superior to those offne control group. The estimated safe and adequate minimal intake of copper (1.5 mg/day) was amply surpassed by the basketball players and runners but was not reached by the handball players. Serum levels and urinary excretion of magnesium, zinc, and copper did not seem related either to their intake or to the type of physical activity performed. The influence of other factors such as nutritional status, bioavailability, intestinal absorption mechanisms, and muscle-level modifications might explain the differences between the different groups of female athletes.

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The Effect of Heat Acclimation on Sweat Microminerals: Artifact of Surface Contamination

Matthew R. Ely, Robert W. Kenefick, Samuel N. Cheuvront, Troy Chinevere, Craig P. Lacher, Henry C. Lukaski, and Scott J. Montain

Heat acclimation (HA) reportedly conveys conservation in sweat micromineral concentrations when sampled from arm sweat, but time course is unknown. The observation that comprehensive cleaning of the skin surface negates sweat micromineral reductions during prolonged sweating raises the question of whether the reported HA effect is real or artifact of surface contamination.

Purpose:

To measure sweat mineral concentrations serially during HA and determine if surface contamination plays a role in the reported mineral reductions.

Methods:

Calcium (Ca), copper (Cu), magnesium (Mg), and zinc (Zn) were measured in sweat obtained from 17 male volunteers using an arm bag on Day 1, 5, and 10 of a HA protocol. To study the role of contamination, sweat was simultaneously (n = 10 subjects) sampled twice daily from a cleaned site (WASH) and unclean site (NO WASH) on the scapular surface.

Results:

Sweat Ca, Cu, and Mg from Arm Bag trended progressively downward from Day 1 to Day 10 of HA (p = .10–0.25). Micromineral concentrations from the WASH site did not change between Day 1, 5, or 10 (Ca = 0.30 ± 0.12 mmol/L, Cu 0.41 ± 0.53 μmol/L; Zn 1.11 ± 0.80 μmol/L). Surface contamination can confound sweat mineral estimates, as sweat Ca and Cu from NO WASH site were initially higher than WASH (p < .05) but became similar to WASH when sampled serially.

Conclusion:

Heat acclimation does not confer reductions in sweat Ca, Cu, Mg, or Zn. When the skin surface is not cleaned, mineral residue inflates initial sweat mineral concentrations. Earlier reports of micromineral reductions during HA may have been confounded by interday cleaning variability.

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Zinc and Copper Biochemical Indices of Antioxidant Status in Elite Athletes of Different Modalities

Josely C. Koury, Astrogildo V. de Oliveira Jr., Emílson S. Portella, Cyntia F. de Oliveira, Gustavo C. Lopes, and Carmen M. Donangelo

The purpose of this study was lo compare zinc and copper biochemical indices of antioxidant status and their relationship in elite athletes of different modalities: aerobic with high-impact (triathletes, n = 10 and long-distance runners, n = 12), anaerobic with high-impact (short-distance runners, n = 9), and anaerobic with low-impact (short-distance swimmers, n = 13). The influence of recent dietary intake and body composition was also evaluated. A venous blood sample was drawn 16-20 hr after competition for the following measurements: packed-cell volume and hemoglobin in blood; copper and zinc in plasma and erythrocytes; ceruloplasmin in plasma; superoxide dismutase activity and metal-lothionein in erythrocyles; and erythrocyte osmotic fragility. Zinc and copper intakes were not different in the athlete groups and did not affect the biochemical indices measured. Athletes of the long-distance high-impact aerobic modalities had higher indices of antioxidant protection (erythrocyte zinc, superoxide dismutase activity, and metallothionein) than those of the short-distance low-impact modalities, suggesting that there is adaptation of the antioxidant capacity to the specific training. Significant correlations were observed in all athletes between erythrocyte zinc, superoxide dismutase activity, and metallothionein consistent with the importance of an adequate zinc status in the response of antioxidant mechanisms to intense exercise.

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Micronutrients (Magnesium, Zinc, and Copper): Are Mineral Supplements Needed for Athletes?

Henry C. Lukaski

Mineral elements, including magnesium, zinc, and copper, are required by the body in modest amounts for the maintenance of health and for the development of optimal physiological function. For athletes, adequate amounts of these minerals are required for physical training and performance. Studies of athletes during training, as compared to nontraining control subjects, indicate the potential for increased losses of minerals in sweat and urine. Some studies report suboptimal intakes of minerals, particularly among athletes who are actively attempting to lose weight to meet standards for competition. However, most athletes consume diets that provide adequate amounts of minerals to meet population standards. Athletes should be counseled to consume foods with high nutrient density rather than to rely on mineral supplements. General use of mineral supplements can alter physiological function and impair health.

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Dietary Intake and Nutritional Status of Athletic and Nonathletic Children in Early Puberty

Tuomo Rankinen, Mikael Fogelholm, Urho Kujala, Rainer Rauramaa, and Matti Uusitupa

Dietary intakes, trace element status, and anthropometric measures were studied in 12- to 13-year-old boys (n = 49) playing ice hockey (AB) and in 11- to 12-year-old girls who were gymnasts, figure skaters, and runners (AG; n = 43), Thirty-five boys (CB) and 53 girls (CG) not involved in supervised sports were controls. After adjustment for sexual maturation, ABs had larger upper arm muscle circumference than CBs. The sum of four skinfolds was smaller in AGs than in CGs. The intake of energy and all micronutrients examined was higher in ABs than in CBs. Micronu-trient Intakes were not different between AGs and CGs. Compared to CBs, serum ferritin and copper concentrations were lower, but serum zinc concentration was higher in ABs. No differences in trace element status were found between AGs and CGs. Blood investigations did not indicate inadequate trace element status in any of the groups studied.

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Interactions among Dietary Fat, Mineral Status, and Performance of Endurance Athletes: A Case Study

Henry C. Lukaski, William W. Bolonchuk, Leslie M. Klevay, David B. Milne, and Harold H. Sandstead

In a pilot study, performance measures and mineral metabolism were assessed in 3 male endurance cyclists who consumed isoenergetic, isonitrogenous diets for 28-day periods in a randomized, crossover design in which dietary carbohydrate, polyunsaturated, or saturated fat contributed about 50% of daily energy intake. Peak aerobic capacity [62 ml/(kg · min)] was unaffected by diet. Endurance capacity at 70–75% peak aerobic capacity decreased with the polyunsaturated fat diet. Copper retention tended to be positive only with saturated fat. Less iron and zinc were retained (intake – losses), and fecal losses of these minerals increased with the polyunsaturated fat. Blood biochemical measures of trace element nutritional status were unaffected by diet, except serum ferritin, which tended to decrease during consumption of the polyunsaturated fat diet. These preliminary results suggest that diets high in polyunsaturated fat, particularly linoleic acid, impair absorption and utilization of iron and zinc, and possibly magnesium, and may reduce endurance performance.

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Sweat Mineral-Element Responses during 7 h of Exercise-Heat Stress

Scott J. Montain, Samuel N. Cheuvront, and Henry C. Lukaski

Context:

Uncertainty exists regarding the effect of sustained sweating on sweat mineral-element composition.

Purpose:

To determine the effect of multiple hours of exercise-heat stress on sweat mineral concentrations.

Methods:

Seven heat-acclimated subjects (6 males, 1 female) completed 5 × 60 min of treadmill exercise (1.56 m/s, 2% grade) with 20 min rest between exercise periods in 2 weather conditions (27 °C, 40% relative humidity, 1 m/s and 35 °C, 30%, 1 m/s). Sweat was collected from a sweat-collection pouch attached to the upper back during exercise bouts 1, 3, and 5. Mineral elements were determined by using inductively coupled plasma-emission spectrography.

Results:

At 27 °C, sweat sodium (863 [563] µg/mL; mean [SD]), potassium (222 [48] µg/mL), calcium (16 [7]) µg/mL), magnesium (1265 [566] ng/mL), and copper (80 [56] ng/mL) remained similar to baseline over 7 h of exercise-heat stress, whereas sweat zinc declined 42–45% after the initial hour of exercise-heat stress (Ex1 = 655 [362], Ex3 = 382 [168], Ex5 = 355 [288] µg/mL, P < 0.05). Similar outcomes were observed for sweat zinc at 35 °C when sweat rates were higher. Sweat rate had no effect on sweat trace-element composition.

Conclusions:

Sweat sodium, potassium, and calcium losses during multiple hours of sustained sweating can be predicted from initial sweat composition. Estimates of sweat zinc losses, however, will be overestimated if sweat zinc conservation is not accounted for in sweat zinc-loss estimates.

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Rapid Facial Cryotherapy for Combat Sports: A Comparison of Materials and Methods for Cooling Facial Tissues in 60 Seconds or Less

Tyler A. Beauregard, Jade Vaile, Lucas Whitney, Mark Merrick, and Valerie Moody

ice, surgical steel, copper, commercial cold pack, aluminum, brass, ice pack, and a saltwater pack, to cause surface temperature changes of the face within 60 seconds of application. We hypothesized that a different material will have a greater cooling effect than the traditional, stainless