Nutritional and physiological status of U.S. national figure skaters

Bone density, microarchitecture and strength in elite figure skaters is discipline dependent

OBJECTIVES

In elite figure skaters, to determine if there was a difference in volumetric bone mineral density and bone strength between 1) figure skaters and population-based normative data, 2) single or pair skaters and ice dancers, and 3) the landing and takeoff legs.

DESIGN

Cross-sectional.

METHODS

Figure skaters had their non-dominant distal radius and bilateral tibia scanned using high-resolution peripheral quantitative computed tomography. Volumetric bone mineral density was determined at the total, cortical and trabecular compartments, and finite element analysis estimated bone strength. Normative data was used to compare the total bone mineral density of figure skaters to a population-based cohort. Independent t-tests compared differences between skating discipline, and paired t-tests compared skeletal parameters for the landing and takeoff leg.

RESULTS

Twenty elite skaters (mean age 22 ± 6.2; female = 11, male = 9) completed scans. Compared with the general population, the mean percentile rank for skaters' total volumetric bone mineral density was below normal at the radius (27th percentile) and normal at the tibia (54th percentile). Single or pair skaters had more robust bone in the landing compared with their takeoff leg. Specifically, the landing leg had higher total bone mineral density (2.8%) and trabecular bone mineral density (6.5%), and superior bone strength (8.5%) than the takeoff leg (p < 0.05).

CONCLUSIONS

Volumetric bone mineral density and strength differences in figure skaters were discipline dependent. Side-to-side differences were observed in single and pair skaters where the landing leg is denser, larger and stronger than the takeoff leg.

Effects of vitamin D3 supplementation on serum 25(OH)D concentration and strength in athletes: a systematic review and meta-analysis of randomized controlled trials

Background

The purpose of this systematic review and meta-analysis is to investigate the effects of vitamin D3 supplementation on skeletal muscle strength in athletes. Vitamin D3 supplements or vitamin D3 fortified foods always have claims for bringing people health benefits including bone and muscle health. An up-to-date rigorous systematic review and meta-analysis is important to better understand the effect of vitamin D3 supplementation on muscle strength.

Methods

English written randomized controlled trials (RCTs) that looked at effects of vitamin D3 supplementation on muscle strength in healthy athletes were searched using three databases (PubMed, Embase and Cochrane Library). Serum 25(OH)D above 30 ng/mL is considered to be sufficient in this systematic review and meta-analysis.

Results

Five RCTs with 163 athletes (vitamin D3 n = 86, placebo n = 77) met inclusion criteria. Fourteen athletes were lost to follow-up and 149 athletes (vitamin D3 n = 80, placebo n = 69) were documented with complete result. Among athletes with baseline serum 25(OH)D values suggesting insufficiency, vitamin D3 daily dosage at 5000 IU for over 4 weeks led to a serum 25(OH)D concentration of 31.7 ng/mL. Athletes with sufficient serum 25(OH)D level at baseline were recruited in only one study, and the participants of which were assigned to either vitamin D3 at a daily dosage of 3570 IU or placebo for 12 weeks, their serum 25(OH)D sufficiency (VD: 37.2 ± 7.6 vs. 45.6 ± 7.6; PL: 38 ± 6.8 vs. 32 ± 8.4) was well maintained above the cut-off boundary. One repetition maximum Bench Press (1-RM BP) was not improved significantly (SMD 0.07, 95% CI: − 0.32 to 0.47, P = 0.72) and there was no significant increase in maximal quadriceps contraction (SMD -2.14, 95% CI: − 4.87 to 0.59, P = 0.12). Furthermore, there was no significant overall effect of vitamin D3 intervention on muscle strength in this meta-analysis (SMD -0.75, 95% CI: − 1.82 to 0.32, P = 0.17).

Conclusion

Although, serum 25(OH)D concentrations after supplementation reached sufficiency was observed, muscle strength did not significantly improve at this point of current meta-analysis. Additional well-designed RCTs with large number of participants examined for the effect of vitamin D3 supplementation on serum 25(OH)D concentrations, muscle strength in a variety of sports, latitudes and diverse multicultural populations are needed.

Eating attitudes and food intakes of elite adolescent female figure skaters: a cross sectional study

BACKGROUND

Elite adolescent female figure skaters compete in an aesthetic-based sport that values thin builds and lithe figures. To conform to the sport's physical requirements, skaters may alter their eating patterns in unhealthful directions. This study assesses the eating attitudes and dietary intakes of elite adolescent female figure skaters to assess the potential nutritional risks among them.

METHODS

Thirty-six elite competitive adolescent female figure skaters (mean age 16 ± 2.5 SD years) completed self-administered three-day records of dietary intake and simultaneous physical activity records during training season. Two months later, they attended a national training camp during which they completed the Eating Attitudes Test (EAT-40), provided fasting blood samples, and had heights and weights measured.

RESULTS

Participants' mean body mass index (BMI) was 19.8 ± 2.1 SD. Their BMIs were within the normal range, and the majority (70%) did not report a history of recent weight loss. The mean EAT-40 score was normal (19.5 ± 13.5 SD) and below the cut-off score of 30 that indicates clinically significant eating pathology. However, one-quarter of the skaters had EAT-40 scores above 30. The skaters reported a mean energy intake of 1491 ± 471 SD kcal/day (31 ± 10 SD kcal/kg), with 61.6% of calories from carbohydrate, 14.6% from protein, and 23.7% from fat. Their reported dietary intakes were high in carbohydrates but low in total energy, fat, and bone-building nutrients.

CONCLUSIONS

Although these highly active young women compete in a sport that prizes leanness, they had appropriate weights. The athletes reported dietary intakes that were far below estimated energy needs and were at moderate risk of disordered eating. Anticipatory guidance is warranted to improve their dietary intakes, particularly of bone-building nutrients.

Carbohydrate supplementation delays DNA damage in elite runners during intensive microcycle training

The aim of this study was to evaluate the effect of carbohydrate supplementation on free plasma DNA and conventional markers of training and tissue damage in long-distance runners undergoing an overload training program. Twenty-four male runners were randomly assigned to two groups (CHO group and control group). The participants were submitted to an overload training program (days 1-8), followed by a high-intensity intermittent running protocol (10 × 800 m) on day 9. The runners received maltodextrin solution (CHO group) or zero energy placebo solution as the control equivalent before, during, and after this protocol. After 8 days of intensive training, baseline LDH levels remained constant in the CHO group (before: 449.1 ± 18.2, after: 474.3 ± 22.8 U/L) and increased in the control group (from 413.5 ± 23.0 to 501.8 ± 24.1 U/L, p < 0.05). On day 9, LDH concentrations were lower in the CHO group (509.2 ± 23.1 U/L) than in the control group (643.3 ± 32.9 U/L, p < 0.01) post-intermittent running. Carbohydrate ingestion attenuated the increase of free plasma DNA post-intermittent running (48,240.3 ± 5,431.8 alleles/mL) when compared to the control group (73,751.8 ± 11,546.6 alleles/mL, p < 0.01). Leukocyte counts were lower in the CHO group than in the control group post-intermittent running (9.1 ± 0.1 vs. 12.2 ± 0.7 cells/µL; p < 0.01) and at 80 min of recovery (10.6 ± 0.1 vs. 13.9 ± 1.1 cells/µL; p < 0.01). Cortisol levels were positively correlated with free plasma DNA, leukocytes, and LDH (all r > 0.4 and p < 0.001). The results showed that ingestion of a carbohydrate beverage resulted in less DNA damage and attenuated the acute post-exercise inflammation response, providing better recovery during intense training.

Athletes' dietary intake was closer to French RDA's than those of young sedentary counterparts

It has been demonstrated that athletes' dietary intake was relatively well-balanced according to the recommended dietary allowances (RDAs). In contrast, other studies have shown that athletes may have low energy intake or imbalance of protein and fat and insufficient minerals and vitamins. Nonetheless, we hypothesized that practicing a sport may allow young adults to have a nutritional status closer to recommended values. The purpose of this experiment was to study the nutritional status of young French adults, particularly to compare the nutritional status of trained young male and female athletes to those of young sedentary control subjects, and to national RDAs. A total of 85 young adults were recruited and filled a 4-day food and physical activity record. Dietary intake, energy expenditure, energy balance, carbohydrate, protein, fat, water, vitamins, and minerals were recorded. Data were analyzed with a software Nutrilog and statistics with Sigma Stat. Energy intake values were 9874 +/- 3050 kJ for the athletes and 7506 +/- 1845 kJ for control subjects. Athletes' nutritional status was closer to French RDAs than those of sedentary subjects who present a lower energy intake, a greater percentage of the energy intake from fat and lower values for minerals and vitamins. In conclusion, practicing a sport may allow athletes to balance their energy intake and expenditure and could be a good way to have a nutritional status closer to RDAs. Educational programs for students on proper food selection, eating habits and physical activity are needed to improve the nutritional status of these young French adults, particularly in sedentary students.

Serum vitamin E concentration and osmotic fragility in female long-distance runners

The objective of this study was to assess the nutritional adequacy of sub-elite runners with irregular menstrual function (n=10) and that of a comparable group of runners with regular menstrual function (n=10), with a special focus on vitamin E. Based on 3 days' records of weighed dietary intake, the mean energy intakes of micro- and macronutrients were estimated. Both estimated daily energy intake (irregular: 9.9+/-0.4 MJ; regular: 12.2+/-0.7 MJ; mean+/-sx) and intake of dietary fat (irregular: 61+/-6 g; regular: 98+/-12 g) were lower in athletes with irregular menstrual function than in athletes with regular menstrual function (P=0.01). Estimated intake of vitamin E was below recommended values in both groups. Serum concentrations of alpha-tocopherol were used to evaluate vitamin E status, which were normal in athletes with regular menstrual function (27.3+/-3.6 micromol.l(-1)) but below normal values in athletes with irregular menstrual function (15.7+/-0.8 micromol.l(-1); P=0.01). Furthermore, post-exercise osmotic fragility in red blood cells was inversely related to resting alpha-tocopherol concentrations. Our results indicate that irregular menstrual function in athletes on a low-fat diet is associated with low concentrations of circulating alpha-tocopherol, rendering the red blood cells more susceptible to haemolysis in connection with physical activity.

Nutritional and Plasmatic Antioxidant Vitamins Status of Ultra Endurance Athletes

OBJECTIVE

The "Marathon des Sables" (MDS) is a competition known to induce oxidative stress. Antioxidant vitamins prevent exercise-induced oxidative damages. The purpose of this study was to evaluate daily intake and plasma level of the main antioxidant vitamins (alpha-tocopherol, vitamin C, beta-carotene and retinol) in 19 male athletes who participated in this competition.

METHODS

Data collected before the beginning of the competition included daily dietary intake using a 7-day food record and plasma biochemical measurements (alpha-tocopherol, vitamin C, beta-carotene and retinol).

RESULTS

First, total energy intake was obviously lower than the energetic intake usually observed in well-trained endurance athletes. Second, antioxidant vitamins intake was also insufficient. Indeed, the intake was lower than the French Dietary Reference Intakes (DRI) for this population in 18 subjects for vitamin E and 6 subjects for vitamin C, beta-carotene and Retinol Equivalent. As a significant relationship was found between total energy intake and the intake of vitamin E (r = 0.73; p < 0.001) and vitamin C (r = 0.78; p < 0.001), the low total energy intake contributed partially to the insufficient antioxidant vitamins intake. The dietary questionnaire analysis also revealed a low intake of vegetable oils, fruits and vegetables. However, plasma concentrations of these antioxidant vitamins were similar to the literature data observed in athletes.

CONCLUSION

This study evidenced obvious insufficient energy intake in ultra endurance athletes associated with a low antioxidant vitamin intake.

Multivitamin-mineral supplementation prevents lipid peroxidation during "the Marathon des Sables"

OBJECTIVE

We investigated the effect of a moderate mutivitamin and mineral supplementation containing mainly vitamin C (150.0 mg.day(-1)), vitamin E (24.0 mg.day(-1)) and beta-carotene (4.8 mg.day(-1)) prior to and during an extreme running competition -the Marathon des Sables (MDS)- that consisted of six long races in the desert.

METHODS

Seventeen athletes participated in our double blind, placebo-controlled study. Blood samples were collected prior to the supplementation i.e. three weeks before the competition (D-21), two days prior to the MDS (D-2), after the third race (D3) and at the end of the competition (D7). Erythrocyte antioxidant enzyme activity (glutathione peroxidase (GPx), superoxide dismutase (SOD)), erythrocyte glutathione level (GSH), plasma non-enzymatic antioxidant status (uric acid, vitamin C, alpha-tocopherol, retinol, beta-carotene), markers of plasma lipid peroxidation (thiobarbituric reactive substances (TBARS)), reactive carbonyl derivatives (RCD) and membrane damage (creatine kinase and lactate dehydrogenase activities) were measured.

RESULTS

In both groups, GSH levels, uric acid levels and membrane damage significantly increased during the competition while SOD activity significantly decreased. In Supplemented group, plasma alpha-tocopherol, beta-carotene and retinol levels significantly increased after three weeks of supplementing. In contrast to Placebo group, alpha-tocopherol, vitamin C and retinol levels were significantly affected by the competition in Supplemented group. Moreover, no increase in TBARS was observed in Supplemented group during the competition, whereas TBARS significantly increased at D3 in the placebo group.

CONCLUSION

The moderate multivitamin-mineral supplementation prevented the transient increase in TBARS levels during this extreme competition.

Micronutrient requirements for athletes

Vitamins and minerals are necessary for many metabolic processes in the body and are important in supporting growth and development. Vitamins and minerals also are required in numerous reactions involved with exercise and physical activity, including energy, carbohydrate, fat and protein metabolism, oxygen transfer and delivery, and tissue repair. The vitamin and mineral needs of athletes have always been a topic of discussion. Some researchers state that athletes require more vitamins and minerals than their sedentary counterparts, whereas other researchers do not report greater micronutrient requirements. The intensity, duration, and frequency of the sport/workout and the overall energy and nutrient intakes of the individual all have an impact on whether or not micronutrients are required in greater amounts. This article evaluates the vitamin and mineral needs of athletes.

Contribution of meals and snacks to nutrient intake of male and female elite figure skaters during peak competitive season

OBJECTIVE

To examine the contribution of breakfast, lunch, dinner and snack to the macronutrient and micronutrient intake of elite male and female figure skaters during their competitive season.

SUBJECTS

Male (n = 46) and female (n = 48) figure skaters who participated in the 1999 U.S. National Figure Skating Championships completed the study.

METHODS

Each athlete completed three-day food records, during the athlete's competitive season. Food records were analyzed using Nutritionist V software. Macronutrient and micronutrient contributions from meals were assessed.

RESULTS

Lunch and dinner meals were the main contributors to the total calorie intake of these skaters (27% and 32%, respectively). Likewise, lunch and dinner were the main contributors to the total protein (27% and 41%), carbohydrate (26% and 29%), fat (30% and 32%), saturated fat (29% and 32%) and polyunsaturated fat (31% and 32%) intakes. Dinner was the main source of the monounsaturated fat (34%), cholesterol (40%) and dietary fiber (34%). Breakfast was the main source of dietary folate (36%), whereas iron and calcium intakes were mainly contributed by breakfast and dinner (29% and 32%, 27% and 29%, respectively).

CONCLUSION

These elite figure skaters appear to be starting their day with low energy reserves and therefore need to be educated about the benefits of consuming breakfast. These athletes also need to be educated about consuming adequate calories throughout the day in order to meet the energy needs of their activity. It is thus important to monitor eating patterns throughout the day to ensure adequate energy intake to sustain the physical and mental aspects of the athletes' training and performance.

Nutritional status of teenage female competitive figure skaters

OBJECTIVE

To assess the nutritional status of female competitive figure skaters during preseason, competitive season, and off-season.

SUBJECTS

Eighteen female competitive figure skaters, age range 14 to 16 years, from the New England region.

STATISTICS

Data was analyzed by repeated measures analysis of variance, Duncan Multiple Range Tests, one-sample t tests, and confidence intervals.

DESIGN

Nutrient intakes were determined from 3-day diet records. Body composition was assessed through heights, weights, and underwater weighing. Blood samples were drawn for analysis of selected indexes of nutritional status.

RESULTS

Height and weight did not differ significantly among the seasons. Body fat was 1.1 kg higher off-season compared with preseason. Energy intake over the 3 seasons did not vary significantly (mean preseason: 1,678 kcal/day; competitive season, 1,630 kcal/day; off-season: 1,673 kcal/day) (P>.05). During the competitive season 78%, 50%, and 44% of the skaters had intakes less than 67% of RDA for folate, iron, and calcium, respectively. Most of the biochemical indexes of nutritional status were within normal limits.

CONCLUSIONS

The results indicate that teenage female skaters have relatively low energy intake and inadequate intakes of certain nutrients, which may account for some of the observed seasonal variations in blood markers of nutritional status. These findings point to the need for nutrition education for these athletes, especially during their competitive season when nutritional status may be compromised.

Dietary intake of elite figure skating dancers

The main objective of the present study was to examine the dietary intake and physiological status of members of the US National Figure Skating Dance Team. Study participants included seven female and seven male figure skating dance pairs. Three-day food records were collected from each dancer and analyzed using a computerized nutrient database. Height, body weight and skinfold measurements were completed on each dancer. Body fat was estimated using the Jackson et al prediction equations. Fasting blood samples were collected for biochemical analysis. Total energy intake of female dancers (1416 kcal/d, 339 kjoules/day) was considerably lower than the dietary recommendations, while the male dancers appeared to have adequate energy intake (2837 kcal/d, 679 kjoules/day). Carbohydrate intake of both male and female dancers was below the recommendations, 44% and 51%, respectively, whereas total fat and protein intake of both male and female dancers were higher than the dietary recommendations. All dancers met at least 2/3(rd) of the dietary recommendations for all micro-nutrients, except folate and zinc intake of the female dancers, which were 68% and 62% of the recommended values. Although, blood lipid concentrations and other physiological parameters of the overall group were within normal ranges, two of the dancers (14% of the dancers) had elevated blood cholesterol concentrations and low iron status. The results of the present study suggest that these elite figure skating dancers, especially females, may not be consuming adequate amounts of energy-yielding nutrients and those that influence bone health. Future studies are needed to examine the effects of nutritional status on performance of these figure skating dancers and to develop strategies to improve the nutritional status of these elite dancers.

Energy and macronutrient intakes of elite figure skaters

OBJECTIVES

Dietary guidelines for athletes emphasize complex carbohydrates. This study examined dietary intakes of elite figure skaters relative to current recommendations in sports nutrition.

PARTICIPANTS

Subjects were male (n=80) and female (n=81) figure skaters taking part in a series of training camps held in Colorado between 1988 and 1995. Mean age was 18 years for men and 16 years for women.

DESIGN

Measures of height, weight, and skinfold thickness were used to calculate body mass index and percent body fat. Blood samples were drawn for analysis of nutritional status. Energy and nutrient intakes were based on 3-day food records.

STATISTICAL ANALYSES

Multivariate regression model and correlation analyses used the SPSS for Windows program.

RESULTS

Values of body mass index and percent body fat were similar to those obtained for elite athletes in other studies. Plasma chemistries were in the normal range. Energy intakes (2,329 kcal/day for men and 1,545 kcal/day for women) were below recommended values for sex and age. The skaters derived approximately 50% of their daily energy from sugars and fat. Sugars alone accounted for 25% of daily energy intakes--the skaters consumed between 100 g (women) and 142 g of sugars per day. Sugar and fat intakes, when expressed as percent of daily energy, were inversely linked, providing evidence of a fat-sugar seesaw. Higher-energy diets were higher in fat but lower in carbohydrate and protein.

APPLICATIONS

High consumption of sugars and fat by elite athletes was not associated with overweight or excess body fat. Although recommended diets are usually built around complex carbohydrates, dietetics professionals can address the increased energy needs of elite athletes by recommending energy-dense foods. Sugars and fats are efficient sources of energy per unit volume.