The purpose of this study was to examine the effect of high-intensity physical activity during training on the biochemical status of thiamin and riboflavin in athletes. Thiamin and riboflavin concentrations in whole blood of a group of 19 athletes (6 men and 13 women) were measured during a low-intensity preparatory period and compared with measurements taken during a high-intensity training period. Additional variables measured included anthropometric characteristics, estimated energy expenditure during swim training, distance covered, resting energy expenditure obtained by indirect calorimetry, estimated energy requirement per day, and dietary intake of energy, thiamin, and riboflavin estimated from 3-day food records. For both male and female subjects, no major changes were observed in anthropometric characteristics or dietary intake, but energy expenditure during swim training per day significantly increased in the intensive-training period (496 ± 0 kcal in the preparation period compared with 995 ± 96 kcal in the intensive-training period for male subjects [p < .001] and 361 ± 27 kcal vs. 819 ± 48 kcal, respectively, for female subjects [p < .001]). Blood thiamin concentration decreased significantly during the intensive-training period compared with the preparation period (41 ± 6 ng/ml decreased to 36 ± 3 ng/ml for male subjects [p = .048], and 38 ± 10 ng/ml decreased to 31 ± 5 ng/ml for female subjects [p = .004]); however, the concentration of riboflavin was unchanged. These results suggest that intense training affects thiamin concentration, but not riboflavin concentration, in the whole blood of college swimmers.
Akiko Sato, Yoshimitsu Shimoyama, Tomoji Ishikawa and Nobuko Murayama
Mikael Fogelholm, Seppo Rehunen, Carl-Gustav Gref, Juha T. Laakso, Jari Lehto, Lnkeri Ruokonen and Jaakko-Juhani Himberg
This study evaluated how different training periods affect dietary intake and biochemical indices of thiamin, iron, and zinc status in elite Nordic skiers. Subjects.were 17 skiers and 39 controls, ages 18-38 yrs. Dietary data were collected by 7-day food records at 3-month intervals. Coefficient of variation (CV) was used to indicate magnitude of seasonal changes. Energy intake for the year (28 food record days) was 3,802 kcallday (CV 19.1%) in male skiers, 2,754 kcallday (CV 3.7%) in male controls, 2,812 kcallday (CV 9.1%) in female skiers, and 2,013 kcallday (CV 5.9%) in female controls. CVs for thiamin, riboflavin, vitamin C, calcium, magnesium, iron, and zinc intake were 14.1-23.9% (male skiers), 2.9-15.0% (male controls), 4.8-24.5% (female skiers), and 4.3-1 1.5% (female controls). Seasonal changes in energy, carbohydrate, and micronutrient intakes reflected energy expenditure in male endurance athletes particularly. Erythrocyte transketolase activation coefficients and serum ferritin and zinc concentrations did not differ between skiers and controls. Seasonal variations in these biochemical indices of nutritional status were of the same magnitude in skiers and controls, despite large changes in skiers' physical activity.
Kathleen Woolf and Melinda M. Manore
The B-vitamins (thiamin, ribofavin, vitamin B-6) are necessary in the energy-producing pathways of the body, while folate and vitamin B-12 are required for the synthesis of new cells, such as the red blood cells, and for the repair of damaged cells. Active individuals with poor or marginal nutritional status for a B-vitamin may have decreased ability to perform exercise at high intensities. This review focuses on the B-vitamins and their role in energy metabolism and cell regeneration. For each vitamin, function related to physical activity, requirement, and status measures are given. Research examining dietary intakes and nutritional status in active individuals is also presented. Current research suggests that exercise may increase the requirements for ribofavin and vitamin B-6, while data for folate and vitamin B-12 are limited. Athletes who have poor diets, especially those restricting energy intakes or eliminating food groups from the diet, should consider supplementing with a multivitamin/mineral supplement.
Matthew R. Doyle, Michael J. Webster and Loran D. Erdmann
The purpose of this study was to investigate the effect of oral allithiamine administration on isokinetic parameters of muscle performance and lactate accumulation prior to, during, and in recovery from isokinetic exercise. A double-blind, counterbalanced, crossover experimental design utilizing aBiodex System 2 Isokinetic Dynamometer was used to test 15 healthy college students. Subjects orally ingested either 1 g ·
Dietary intakes of 24 female athletes in various sports were compared inseason and postseason to those reported by 24 nonathletes during the same time period. Diets were analyzed for energy, carbohydrate, fat, protein, vitamins A and C, thiamin, riboflavin, niacin, folacin, calcium, and iron. During the study, the athletes' and nonathletes' diets were similar. Their energy intakes were lower than recommended while their iron and calcium intakes were marginal (less than 70% of the recommended dietary allowance). Although few dietary changes were observed, the nonathletes' diets changed more than those of the athletes during the study. Both groups reduced their energy intakes but only the nonathletes' reduction was significant. Initially many subjects were dieting. More subjects reported dieting during the second recording period. These results suggest that the desire to be thin may influence dietary intakes of female athletes more than changes in exercise training.
Robert A. Niekamp and Janine T. Baer
The purpose of this study was to determine the dietary adequacy of 12 collegiate cross-country runners during a competitive season. Four-day diet records were collected twice during the season and analyzed for total daily energy, macronutrients, vitamin A, vitamin C, thiamin, riboflavin, niacin, vitamin
Paula J. Ziegler, Judith A. Nelson and Satya S. Jonnalagadda
This study assessed the nutrient intake, body composition and biochemical indices of National Figure Skating Championship competitors. Four-day diet records, fasting blood samples, and anthropometric measurements were obtained 2 months after the National Championships from 41 figure skaters 11-18 years of age. Energy, carbohydrate, fat, dietary fiber and cholesterol intake were significantly lower compared to the NHANES III averages for adolescents in the U.S. In general, the mean intakes for most vitamins except vitamin D and E were above the recommended intake. But the athletes had lower intakes of vitamin E and B12, and higher intakes of vitamin C, and thiamin (females only) compared with NHANES III. The mean intakes of magnesium, zinc, and iodine by the male skaters were below the recommended levels, as were the mean intakes of calcium, iron, phosphorus, magnesium, and zinc by the female skaters. Also, the number of servings from vegetable, fruit, dairy, and meat groups were below the recommended levels. Biochemical indices of nutritional status were within normal limits for all skaters. But plasma electrolyte concentrations were indicative of potential dehydration status. The results suggest there is a need to develop dietary intervention and educational programs targeted at promoting optimal nutrient and fluid intakes by these athletes to maintain performance and improve long-term health status.
Jennifer L. Krempien and Susan I. Barr
Energy intakes of adults with spinal cord injury (SCI) have been reported to be relatively low, with many micronutrients below recommended amounts, but little is known about the diets of athletes with SCI. The purpose of this cross-sectional, observational study was to assess energy intakes and estimate the prevalence of dietary inadequacy in a sample of elite Canadian athletes with SCI (n = 32). Three-day self-reported food diaries completed at home and training camp were analyzed for energy (kcal), macronutrients, vitamins, and minerals and compared with the dietary reference intakes (DRIs). The prevalence of nutrient inadequacy was estimated by the proportion of athletes with mean intakes below the estimated average requirement (EAR). Energy intakes were 2,156 ± 431 kcal for men and 1,991 ± 510 kcal for women. Macronutrient intakes were within the acceptable macronutrient distribution ranges. While at training camp, >25% of men had intakes below the EAR for calcium, magnesium, zinc, riboflavin, folate, vitamin B12, and vitamin D. Thiamin, riboflavin, calcium, and vitamin D intakes were higher at home than training camp. Over 25% of women had intakes below the EAR for calcium, magnesium, folate, and vitamin D, with no significant differences in mean intakes between home and training camp. Vitamin/mineral supplement use significantly increased men’s intakes of most nutrients but did not affect prevalence of inadequacy. Women’s intakes did not change significantly with vitamin/mineral supplementation. These results demonstrate that athletes with SCI are at risk for several nutrient inadequacies relative to the DRIs.
Ahmed Ismaeel, Suzy Weems and Darryn S. Willoughby
/A N/A Saturated fat (g) 24.4 (10.4) N/A N/A Vitamin A (μg) 776.4 (418.3) 900 86.3% Vitamin D (IU) 372.3 (574.0) 600 62.05% Vitamin E (mg) 13.9 (8.3) 15 92.7% Vitamin K (μg) 630.5 (675.0) 120 525.4% Vitamin C (mg) 165.7 (118.8) 90 184.1% Thiamin (mg) 1.4 (1.0) 1.2 200.0% Riboflavin (mg) 4.0 (1.3) 1
± 486 Iodine (µg) 139 ± 37 343 ± 109 Thiamin (mg) 3.6 ± 0.6 1.8 ± 0.4 Riboflavin (mg) 4.5 ± 1.0 4.6 ± 1.6 Niacin (mg) 43 ± 7 44 ± 10 Vitamin C (mg) 520 ± 136 49 ± 26 Vitamin A (µg) 1008 ± 643 1516 ± 547 Vitamin D (µg) 4.5 ± 2.7 7.6 ± 2.3 Vitamin E (mg) 18 ± 11 31 ± 6 Vitamin B6 (mg) 5.4 ± 0.7 4.1 ± 1