Calcium and vitamin D can significantly impact bone mineral and fracture risk in women. Unfortunately, calcium intakes in women are low and many elderly have poor vitamin D status. Supplementation with calcium (~1000 mg) can reduce bone loss in premenopausal and late postmenopausal women, especially at sites that have a high cortical bone composition. Vitamin D supplementation slows bone loss and reduces fracture rates in late postmenopausal women. While an excess of nutrients such as sodium and protein potentially affect bone mineral through increased calcium excretion, phytoestrogens in soy foods may attenuate bone loss ihrough eslrogenlike activity. Weight-bearing physical activity may reduce the risk of osteoporosis in women by augmenting bone mineral during the early aduli years and reducing the loss of bone following menopause. High-load activities, such as resistance training, appear to provide the best stimulus for enhancing bone mineral; however, repetitive activities, such as walking, may have a positive impact on bone mineral when performed at higher intensities. Irrespective of changes in bone mineral, physical activities that improve muscular strength, endurance, and balance may reduce fracture risk by reducing the risk of falling. The combined effect of physical activity and calcium supplementation on bone mineral needs further investigation.
Richard D. Lewis and Christopher M. Modlesky
Maria José Tormo, Carmen Navarro, Maria-Dolores Chirlaque, Xavier Barber, Silvia Argilaga, Antonio Agudo, Pilar Amiano, Aurelio Barricarte, Jose M. Beguiristain, Miren Dorronsoro, Carlos Alberto González, Carmen Martínez, José Ramón Quirós and Mauricio Rodríguez
This study evaluated the dietary pattern of foods and nutrients according to levels of vigorous leisure time physical activity (PA) assessed at recruitment within the Spanish cohort of the European Prospective Investigation on Cancer (EPIC) study (37,287 healthy volunteers with complete information). We used a validated PA questionnaire (PAQ) to measure the weekly frequency and duration of different kinds of sport activities. For dietary assessment, we used a validated diet history questionnaire that included all items consumed with a frequency of at least twice a month. We tested differences in food and nutrient intake according to PA duration by means of both an analysis of variance and an analysis of covariance adjusted for confounding factors. Linear increases or decreases in food and nutrient intake across PA levels were tested by means of a regression analysis. Only 11% of men and 6% of women performed at least 3 hours/week of intense PA, which is similar to current recommendations. Overall, main nutrient and total energy intakes were similar across different PA levels (<2% change in total energy intake between extreme PA categories). However, the intake of some foods and vitamins did significantly (p ≤ .05) increase as PA increased. The average gender-weighted percentage change in the intake of food and vitamins increased when moving from the lowest levels of PA to the highest. There was an increase in the intake of the following: 15.9% in vegetables, 6.7% in fruit, 9% in fish, 5.6% in dairy products, 10% in vitamin C, 5.9% in vitamin E, 7.2% in retinol, 19.7% in total carotene, 40.1% in α-carotene, 20.4% in ß-carotene, 11.2% in licopene, and 26.1% in lutein. BMI, which was above average for the cohort (mean ± SD: 28.4 ± 4.2), decreased steadily when PA increased. To sum up, in this large Spanish cohort, the differences in dietary intake relative to levels of PA were not found either in the amount of total energy consumed nor in the number of main macronutrients but rather in the intake of certain foods which, while having very little or moderate caloric content, are very rich in highly bioactive elements such as vitamins and provitamins.
Jennifer C. Gibson, Lynneth Stuart-Hill, Steven Martin and Catherine Gaul
Adolescent female team-sport athletes are faced with the challenge of meeting nutrition requirements for growth and development, as well as sport performance. There is a paucity of evidence describing the dietary adequacy of this population in respect to these physiological demands. Therefore, the aim of this study was to comprehensively evaluate the nutrition status of junior elite female soccer athletes.
A total of 33 athletes (15.7 ± 0.7 yr) completed anthropometric assessment, 4-day food records analyzed for macro- and micronutrient intake, and hematological analysis. Energy expenditure was estimated using predictive equations.
Mean sum of 7 skinfolds was 103.1 ± 35.2 mm, and body-mass index was 22.7 ± 2.7. Mean energy intake was 2,079 ± 460 kcal/day, and estimated energy expenditure was 2,546 ± 190 kcal/day. Of the athletes, 51.5% consumed <5g/kg carbohydrate, 27.3% consumed <1.2g/kg protein, and 21.2% consumed <25% of energy intake from fat. A large proportion of athletes did not meet Dietary Reference Intakes for pantothenic acid (54.5%), vitamin D (100%), folate (69.7%), vitamin E (100%), and calcium (66.7%). Compared with recommendations for athletes, 89.3% and 50.0% of participants had depleted iron and 25-hydroxyvitamin D, respectively.
A high proportion of players were not in energy balance, failed to meet carbohydrate and micronutrient recommendations, and presented with depleted iron and vitamin D status. Suboptimal nutrition status may affect soccer performance and physiological growth and development. More research is needed to understand the unique nutrition needs of this population and inform sport nutrition practice and research.
Floris C. Wardenaar, Ingrid J.M. Ceelen, Jan-Willem Van Dijk, Roland W.J. Hangelbroek, Lore Van Roy, Britte Van der Pouw, Jeanne H.M. De Vries, Marco Mensink and Renger F. Witkamp
The use of nutritional supplements is highly prevalent among athletes. In this cross-sectional study, we assessed the prevalence of nutritional supplement use by a large group of Dutch competitive athletes in relation to dietary counseling. A total of 778 athletes (407 males and 371 females) completed a web-based questionnaire about the use of nutritional supplements. Log-binomial regression models were applied to estimate crude and adjusted prevalence ratios (PR) for the use of individual nutritional supplements in athletes receiving dietary counseling as compared with athletes not receiving dietary counseling. Of the athletes, 97.2% had used nutritional supplements at some time during their sports career, whereas 84.7% indicated having used supplements during the last 4 weeks. The top ranked supplements used over the last 4 weeks from dietary supplements, sport nutrition products and ergogenic supplements were multivitamin and mineral preparations (42.9%), isotonic sports drinks (44.1%) and caffeine (13.0%). After adjustment for elite status, age, and weekly exercise duration, dietary counseling was associated with a higher prevalence of the use of vitamin D, recovery drinks, energy bars, isotonic drinks with protein, dextrose, beta-alanine, and sodium bicarbonate. In contrast, dietary counseling was inversely associated with the use of combivitamins, calcium, vitamin E, vitamin B2, retinol, energy drinks and BCAA and other amino acids. In conclusion, almost all athletes had used nutritional supplements at some time during their athletic career. Receiving dietary counseling seemed to result in better-informed choices with respect to the use of nutritional supplements related to performance, recovery, and health.
Emily M. Haymes
Muscle glycogen is the primary source of energy during high intensity exercise. Increasing the carbohydrate content of the diet allows more glycogen to be stored. Some adolescent female athletes (gymnasts, dancers) do not consume adequate amounts of vitamin B6, folacin, and E. Many women have low dietary intakes of calcium and iron. Low calcium intake and physical inactivity are factors associated with the development of osteoporosis. Low iron intake is associated with the development of iron deficiency and anemia. Low ferritin levels (an index of body iron stores) are commonly observed in female athletes.
Jongkyu Kim, Namju Lee, Jangwon Lee, Sung-sook Jung, Sung-ki Kang and Jong-dae Yoon
This research investigated patterns of the use of dietary supplement and doping awareness among high-ranked judoists from 2 countries. Korean (70 men and 31 women) and Japanese (37 men and 34 women) national judo team members were divided into 2 groups (high and low competitive performance levels) according to their international and national rankings. Fifty-nine percent of Korean and 61% of Japanese judoists consumed dietary supplements. Eighty-eight percent of high- and 51% of low-competitive-performance-level Korean judoists consumed dietary supplements. Sixty-eight percent of high- and 57% of low-competitiveperformance- level Japanese judoists consumed dietary supplements. Oriental supplements (34%), vitamins (23%), and protein powder (12%) were the most commonly consumed dietary supplements in Korean judoists. Vitamins (45%), protein powder (33%), and minerals (15%) were the most commonly consumed dietary supplements in Japanese judoists. Thirty-eight percent of judoists from both countries had not received any proper education about antidoping, and 44% of judoists from both countries had not received knowledge of antidoping legislation. There was a significant difference in education about antidoping between high and low competitive-performance levels of Korean judoists (p < .001). Korean judoists received significantly less antidoping education than Japanese judoists (p < .001). The associations for antidoping education and knowledge of antidoping legislation with the use of dietary supplements were 3.46 (95% CI = 1.31–9.12) and 1.63 (95% CI = 0.71–3.76), respectively. Our findings showed that use of dietary supplements in judoists from both countries was increased after experiencing antidoping education.
Satya S. Jonnalagadda, Paula J. Ziegler and Judy A. Nelson
The objectives of this study were to determine food preferences, body image perceptions, dieting behaviors, and nutrient intakes of elite male and female figure skaters. Male (n = 23) and female (n = 26) figure skaters completed a food preference checklist, a questionnaire examining their demographics, dieting behaviors and body image perceptions, and 3-d food records. Male skaters had a higher preference (score ≥ 6) for grains, fruit, meat, dairy, fats, and sweets. Female skaters had higher preference for grains and fruits. Of the female skaters, 30% considered themselves overweight and indicated a preference for a thinner body contour. Both male and female skaters expressed a preference for leaner body contours for members of the opposite gender. Total energy intake, total fat (females) and dietary fiber were below the dietary recommendations. Vitamin E, vitamin D, folate (females), pantothenic acid (females), calcium (females), magnesium, potassium, and phosphorus (females) were less than two-thirds of the dietary recommendations. Macronutrient intake of male skaters was associated with preferences for the grain group, although no association was observed among female skaters. Results suggest that these behaviors and attitudes need to be assessed and addressed among figure skaters, given their impact on dietary intakes and overall well-being.
Susan M. Kleiner, Terry L. Bazzarre and Barbara E. Ainsworth
The nutritional status of 11 female and 13 male elite bodybuilders at the first drug-tested USA Championship was examined through food records kept by subjects. Diets were repetitive and monotonous, and average daily energy and protein contents were relatively similar for men and women. Percent calories from protein, fat, and carbohydrate were 39%, 12%, and 48% for females, and 40%, 11%, and 49% for males, respectively. Females consumed 0% vitamin D, 52% calcium, 76% zinc (as percents of RDA) and below the Estimated Safe and Adequate Dietary Allowance amounts for copper and chromium. Males consumed 46% of vitamin D RDA. Although dietary magnesium intakes were above the RDA, serum magnesium levels in females were below reference values, which should be investigated. Serum zinc levels were high in men and women. Eighty-one percent of females reported recurrent contest-related amenorrhea for 2 ± 1 months precontest. Dietary intakes of men were adequate but the restrictive intakes of women may place them at risk for calcium, copper, and chromium deficiencies.
Veronica A. Mullins, Linda B. Houtkooper, Wanda H. Howell, Scott B. Going and C. Harmon Brown
This study describes the body composition, dietary nutrient intake, dietary practices, and biochemical indices of iron status of elite female American heptathletes during training. Four-day diet records and dietary practice questionnaires were obtained from 19 female heptathletes (26 ± 3 years) during the training season. Anthropometric measurements and fasting blood samples were obtained at the lowest phase of the training cycle. These athletes had a low body fat (13.8 ± 2.7%) and high fat-free mass to height ratios (33.0 ± 2.0 kg/m). Average nutrient intakes were > 67% of the reference intakes for all nutrients except vitamin E. Most dietary nutrient densities were higher than NHANES III nutrient densities for women 20–29 years old. More than 50% of the athletes took vitamin supplements and monitored their hydration status. Fifteen of the 17 athletes reported a normal menstrual cycle. Markers of biochemical iron status were all within the normal range. On average, these athletes were lean with high levels of fat free mass, adequate nutrient intakes, and normal biochemical indices of iron status. However, individual data reveals considerable variability within this group.
Rameswar Pal, Som Nath Singh, Kaushik Halder, Omveer Singh Tomer, Awadh Bihari Mishra and Mantu Saha
This study was conducted to evaluate the effects of yogic practice on resting metabolism and redox status.
The study was conducted on 64 physically trained male volunteers selected randomly at the Air Force Academy. The yoga group (n = 34) practiced yogasana, pranayama, and meditation for 3 months (February–May 2011) and the control group (n = 30) performed physical training. Antioxidant variables in blood samples along with physiological parameters were estimated before and after 3 months.
No significant difference was noted between baseline data of the control group and yoga group. Reduced glutathione, vitamin C, and vitamin E; the ratio of reduced to oxidized glutathione; and total antioxidant status were increased significantly following yogic practice. Activities of superoxide dismutase, glutathione S-transferase, and glutathione reductase were significantly increased, whereas activity of glutathione peroxidase was significantly decreased following yogic practice. Oxidized glutathione decreased significantly following yogic practice. A nonsignificant decrease of hydroperoxides, protein carbonyl, malondialdehyde, and blood sugar was noted in the yoga group. Carbon dioxide elimination and peripheral oxygen saturation increased significantly following yogic practice. No significant changes were observed in the control group following 3 months of physical training.
Regular yogic practice can improve resting metabolism and redox status of the practitioner.