The purpose of this study was to determine the effects of carbohydrate supplementation during intense training on dietary patterns, psychological status, and markers of anaerobic and aerobic performance. Seven members of the U.S. National Field Hockey Team were matched to 7 team counterparts (N = 14). One group was blindly administered a carbohydrate drink containing 1 g·kg−1 of carbohydrate four times daily, while the remaining group blindly ingested a flavored placebo during 7 days of intense training. Subjects underwent pre- and posttraining aerobic and anaerobic assessments, recorded daily diet intake, and were administered the Profile of Mood States (POMS) psychological inventory prior to and following each practice. Results revealed that the carbohydrate-supplemented group had a greater (p < .05) total energy intake, carbohydrate intake, and change (pre vs. post) in time to maximal exhaustion following training while reporting less postpractice psychological fatigue. However, no significant differences were observed in remaining psychological, physiological, or performance-related variables.
Richard B. Kreider, Dawn Hill, Greg Horton, Michael Downes, Sarah Smith and Beth Anders
Eleni Michopoulou, Alexandra Avloniti, Antonios Kambas, Diamanda Leontsini, Maria Michalopoulou, Symeon Tournis and Ioannis G. Fatouros
This study determined dietary intake and energy balance of elite premenarcheal rhythmic gymnasts during their preseason training. Forty rhythmic gymnasts and 40 sedentary age-matched females (10–12 yrs) participated in the study. Anthropometric profile and skeletal ages were determined. Dietary intake and physical activity were assessed to estimate daily energy intake, daily energy expenditure, and resting metabolic rate. Groups demonstrated comparable height, bone age, pubertal development, resting metabolic rate. Gymnasts had lower body mass, BMI, body fat than age-matched controls. Although groups demonstrated comparable daily energy intake, gymnasts exhibited a higher daily energy expenditure resulting in a daily energy deficit. Gymnasts also had higher carbohydrate intake but lower fat and calcium intake. Both groups were below the recommended dietary allowances for fiber, water, calcium, phosphorus and vitamin intake. Gymnasts may need to raise their daily energy intake to avoid the energy deficit during periods of intense training.
JesÚs Rico-Sanz, Walter R. Frontera, Paul A. Molé, Miguel A. Rivera, Anita Rivera-Brown and Carol N. Meredith
This study examined the nutritional and performance status of elite soccer players during intense training. Eight male players (age 17 ± 2 years) of the Puerto Rican Olympic Team recorded daily activities and food intake over 12 days. Daily energy expenditure was 3,833 ± 571 (SD) kcal, and energy intake was 3,952 ± 1,071 kcal, of which 53.2 ± 6.2% (8.3 g ⋅ kg BW−1) was from carbohydrates (CHO), 32.4 ± 4.0% from fat, and 14.4 ± 2.3% from protein. With the exception of calcium, all micronutrients examined were in accordance with dietary guidelines. Body fat was 7.6 ± 1.1% of body weight. Time to completion of three runs of the soccer-specific test was 37.65 ± 0.62 s, and peak torques of the knee flexors and extensors at 60° ⋅ s−1 were 139 ± 6 and 225 ± 9 N ⋅ m, respectively. Players' absolute amounts of CHO seemed to be above the minimum recommended intake to maximize glycogen storage, but calcium intakes were below recommended. Their body fat was unremarkable, and they had a comparatively good capacity to endure repeated bouts of intense soccer-specific exercise and to exert force with their knee extensors and flexors.
Bruno Marrier, Yann Le Meur, Julien Robineau, Mathieu Lacome, Anthony Couderc, Christophe Hausswirth, Julien Piscione and Jean-Benoît Morin
To compare the sensitivity of a sprint vs a countermovement-jump (CMJ) test after an intense training session in international rugby sevens players, as well as analyze the effects of fatigue on sprint acceleration.
Thirteen international rugby sevens players completed two 30-m sprints and a set of 4 repetitions of CMJ before and after a highly demanding rugby sevens training session.
Change in CMJ height was unclear (–3.6%; ±90% confidence limits 11.9%. Chances of a true positive/trivial/negative change: 24/10/66%), while a very likely small increase in 30-m sprint time was observed (1.0%; ±0.7%, 96/3/1%). A very likely small decrease in the maximum horizontal theoretical velocity (V0) (–2.4; ±1.8%, 1/4/95%) was observed. A very large correlation (r = –.79 ± .23) between the variations of V0 and 30-m-sprint performance was also observed. Changes in 30-m sprint time were negatively and very largely correlated with the distance covered above the maximal aerobic speed (r = –.71 ± .32).
The CMJ test appears to be less sensitive than the sprint test, which casts doubts on the usefulness of a vertical-jump test in sports such as rugby that mainly involve horizontal motions. The decline in sprint performance relates more to a decrease in velocity than in force capability and is correlated with the distance covered at high intensity.
Akiko Sato, Yoshimitsu Shimoyama, Tomoji Ishikawa and Nobuko Murayama
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.
Tal Marom, David Itskoviz, Haim Lavon and Ishay Ostfeld
Exertional heat stroke (EHS) is a major concern in military trainees performing intense physical exercise, with substantial morbidity rates. Prehospital diagnosis of EHS is essentially clinical. Thus, soldiers, command personnel, and medical staff are taught to recognize this injury and immediately begin aggressive treatment to prevent further deterioration.
Patients and Methods:
During 2007, 5 otherwise healthy Israeli Defense Forces (IDF) soldiers were diagnosed with EHS while performing strenuous exercise. They were treated vigorously according to the IDF EHS-treatment protocol and were referred to the emergency department.
On arrival at the emergency department, physical examination including rectal temperature was unremarkable in all soldiers. Blood and urine workup showed near-normal values. No other medical conditions that could have explained the clinical presentation were found. All soldiers were discharged shortly afterward, with no further consequences. A heat-tolerance test was performed several weeks after the event and was interpreted as normal. All soldiers returned to active service.
Because the initial clinical findings were very suggestive of EHS and because no other condition could have explained the prehospital transient hyperthermia, we suggest that these soldiers were correctly diagnosed with EHS, and we propose that rapid vigorous cooling prevented further deterioration and complications. We suggest calling this condition aborted heat stroke.
of IGF-I levels can also assist athletes in the preparation for competition. Circulating IGF-I and physical conditioning scores decreased during periods of intense training and returned to baseline levels during relative tapering down in junior handball players prior to the world championships ( 9
Eric S. Rawson, Mary P. Miles and D. Enette Larson-Meyer
maintain health, adapt to exercise, and increase the quality and quantity of their training. Creatine monohydrate could be recommended for promoting recovery from, and muscular adaptations to, intense training; recovery from periods of injury that result in extreme inactivity; cognitive processing; and
Barry Braun, Priscilla M. Clarkson, Patty S. Freedson and Randall L. Kohl
The effects of dietary supplementation with Coenzyme Q10 (CoQlO), a reputed performance enhancer and antioxidant, on physiological and biochemical parameters were examined. Ten male bicycle racers performed graded cycle ergometry both before and after being given 100 mg per day CoQlO or placebo for 8 weeks. Analysis of variance showed a significant difference between groups for postsupplementation serum CoQ10. Although both groups demonstrated training related improvements in all physiological parameters over the course of the study, there were no significant differences between the two groups (p>.05). Both groups showed a 21 % increase in serum MDA (an index of lipid peroxidation) after the presupplementation exercise test. After 8 weeks this increase was only 5 % , and again was identical for both groups. Supplementation with CoQlO has no measurable effect on cycling performance,
Monna Arvinen-Barrow, Brian Hemmings, Caryl A. Becker and Lynn Booth
To gain an insight to the existing suggestions and recommendations on chartered physiotherapists’ preferred methods of delivery for further training in sport psychology.