Low energy availability can place athletes at increased risk of injury and illness and can be detected by a lower metabolic rate. The lowest metabolic rate is captured at the bedside, after an overnight fast and termed inpatient resting energy expenditure (REE). Measurements done in a laboratory with a shorter overnight fast are termed outpatient REE. Although important to know what the lowest energy expenditure, a bedside measure and/or 12-hr fast is not always practical or logistically possible particularly when you take into account an athlete’s training schedule. The aim of this investigation was to compare a bedside measure of resting metabolism with a laboratory measure in athletes following an 8-hr fast. Thirty-two athletes (24 females and eight males) underwent measures of resting metabolism using indirect calorimetry once at their bedside (inpatient) and once in a simulated laboratory setting (outpatient). Paired t test was used to compare the mean ± SD differences between the two protocols. Inpatient REE was 7,302 ± 1,272 kJ/day and outpatient REE was 7,216 ± 1,116 kJ/day (p = .448). Thirteen participants repeated the outpatient protocol and 17 repeated the inpatient protocol to assess the day-to-day variation. Reliability was assessed using the intraclass correlation coefficient and typical error. The inpatient-protocol variability was 96% with a typical error of 336.2 kJ/day. For the outpatient protocol, the intraclass correlation coefficient and typical error were 87% and 477.6 kJ/day, respectively. Results indicate no difference in REE when measured under inpatient and outpatient conditions; however, the inpatient protocol has greater reliability.
Julia L. Bone and Louise M. Burke
Chih-Chia (JJ) Chen and Shannon D.R. Ringenbach
János Négyesi, Menno P. Veldman, Kelly M.M. Berghuis, Marie Javet, József Tihanyi and Tibor Hortobágyi
Sensory input can modify motor function and magnify interlimb transfer. We examined the effects of low-intensity somatosensory electrical stimulation (SES) on motor practice-induced skill acquisition and intermanual transfer. Participants practiced a visuomotor skill for 25 min and received SES to the practice or the transfer arm. Responses to single- and double-pulse transcranial magnetic stimulation were measured in both extensor carpi radialis. SES did not further increase skill acquisition (motor practice with right hand [RMP]: 30.8% and motor practice with right hand + somatosensory electrical stimulation to the right arm [RMP + RSES]: 27.8%) and intermanual transfer (RMP: 13.6% and RMP + RSES: 9.8%) when delivered to the left arm (motor practice with right hand + somatosensory electrical stimulation to the left arm [RMP + LSES]: 44.8% and 18.6%, respectively). Furthermore, transcranial magnetic stimulation measures revealed no changes in either hand. Future studies should systematically manipulate SES parameters to better understand the mechanisms of how SES affords motor learning benefits documented but not studied in patients.
Stephen M. Glass, Brian L. Cone, Christopher K. Rhea, Donna M. Duffy and Scott E. Ross
Context: Previous work suggests that balance behavior is a sex-dependent, complex process that can be characterized by linear and nonlinear metrics. Although a certain degree of center of pressure variability may be expected based on sexual dimorphism, there is evidence to suggest that these effects are obscured by potential interactions between sex and anthropometric factors. To date, no study has accounted for such interactive effects using both linear and nonlinear measures. Objective: This investigation sought to analyze interactive models featuring sex, height, and weight as predictors of linear and nonlinear aspects of postural control. Design: Cross-sectional study. Setting: Controlled laboratory. Participants: A total of 26 males (23.80 [3.44] y, 177.87 [6.44] cm, 81.70 [10.80] kg) and 28 females (21.14 [2.03] y, 169.57 [8.80] cm, 64.48 [8.86] kg) were sampled from a healthy university population. MainOutcomeMeasures: Linear (range [RNG], velocity [VEL], and SD) and nonlinear (detrended fluctuation analysis scaling exponent, multivariate multiscale sample entropy [MMSECI]) summary metrics of center of pressure time series. Procedure: Participants stood on a force plate for 20 seconds in 3 conditions: double (D), single (S), and tandem (T) stance. Data for each stance condition were analyzed using regression models with interaction terms for sex × height and sex × weight. In D, weight had a positive, significant main effect on VELy, MMSECId, and MMSECIv. In men, height was observed to have a positive effect on SDy (S), RNGy (S), and RNGx (T) and a negative effect on MMSECIv (T). In women, weight was observed to have a positive effect on SDy and VELx (both T). Conclusions: Our findings suggest that men and women differ with respect to certain linear and nonlinear aspects of balance behavior, and that these differences may reflect sex-specific behavioral patterns in addition to effects related to sexual dimorphism.
Darren G. Burke, Darren G. Candow, Philip D. Chilibeck, Lauren G. MacNeil, Brian D. Roy, Mark A. Tarnopolsky and Tim Ziegenfuss
The purpose of this study was to compare changes in muscle insulin-like growth factor-I (IGF-I) content resulting from resistance-exercise training (RET) and creatine supplementation (CR). Male (n = 24) and female (n = 18) participants with minimal resistance-exercise-training experience (≥1 year) who were participating in at least 30 min of structured physical activity (i.e., walking, jogging, cycling) 3–5 ×/wk volunteered for the study. Participants were randomly assigned in blocks (gender) to supplement with creatine (CR: 0.25 g/kg lean-tissue mass for 7 days; 0.06 g/kg lean-tissue mass for 49 days; n = 22, 12 males, 10 female) or isocaloric placebo (PL: n = 20, 12 male, 8 female) and engage in a whole-body RET program for 8 wk. Eighteen participants were classified as vegetarian (lacto-ovo or vegan; CR: 5 male, 5 female; PL: 3 male, 5 female). Muscle biopsies (vastus lateralis) were taken before and after the intervention and analyzed for IGF-I using standard immunohistochemical procedures. Stained muscle cross-sections were examined microscopically and IGF-I content quantified using image-analysis software. Results showed that RET increased intramuscular IGF-I content by 67%, with greater accumulation from CR (+78%) than PL (+54%; p = .06). There were no differences in IGF-I between vegetarians and nonvegetarians. These findings indicate that creatine supplementation during resistance-exercise training increases intramuscular IGF-I concentration in healthy men and women, independent of habitual dietary routine.
Dianne Neumark-Sztainer, Richard F. MacLehose, Allison W. Watts, Marla E. Eisenberg, Melissa N. Laska and Nicole Larson
Obesity in young adults is of public health concern, given its high prevalence and potential adverse health consequences. 1 – 3 Innovative strategies are needed that are widely acceptable and effective in long-term weight management. 4 Given that some research suggests that overweight individuals
Luis F. Gómez, Olga L. Sarmiento, Diego I. Lucumí, Gladys Espinosa, Roberto Forero and Adrian Bauman
Utilitarian physical activity confers health benefits, but little is known about experiences in developing countries. The objective was to examine the prevalence and factors associated with walking and bicycling for transport in adults from Bogotá.
A cross-sectional study including 1464 adults age 18 to 29 y during the year 2002.
16.7% reported bicycling for at least 10 min during the last week and 71.7% reported walking for at least 90 min during the last week. Bicycling was more likely among adults living in Tunjuelito (flat terrain), who use the “ciclovía” (car-roads for recreational bicycling on holidays/Sundays) or reporting physical activity during leisure-time and less likely among women, or adults with college education. Walking was more likely among adults reporting physical activity during leisure time and less likely among housewives/househusbands or those living in Tunjuelito.
Programs that promote walking or bicycling in Bogotá should consider differences in individual and environmental factors.
Mikael Fogelholm, Inkeri Ruokonen, Juha T. Laakso, Timo Vuorimaa and Jaakko-Juhani Himberg
By means of a 5-week vitamin B-complex .supplementation, associations between indices of vitamin B1, B2, and B6, status (activation coefficients [AC] for erythrocyte transketolase, glutathione reductase, and aspartate aminotransferase) and exercise-induced blood lactate concentration were studied. Subjects, 42 physically active college students (18–32 yrs), were randomized into vitamin (n=22) and placebo (n=20) groups. Before the supplementation there were no differences in ACs or basal enzyme activities between the groups. The ACs were relatively high, suggesting marginal vitamin status. In the vitamin group, all three ACs were lower (p<0.0001) after supplementation: transketolase decreased from l. 16 (1.14–1.18) (mean and 95% confidence interval) to 1.08 (1.06–1.10); glutathione reductase decreased from 1.33 (1.28–1.39) to 1 .I4 (1.1 1–1.17); and aspartate aminotransferase decreased from 2.04 (1.94–2.14) to 1.73 (1.67–1.80). No changes were found after placebo. Despite improved indices of vitamin status, supplementation did not affect exercise-induced blood lactate concentration. Hence no association was found between ACs and blood lactate. It seems that marginally high ACs do not necessarily predict altered lactate metabolism.
Edith Filaire, Alain Massart, Jiewen Hua and Christine Le Scanff
The aims of study were to examine the eating behaviors among 26 professional female tennis players and to assess the diurnal patterns of stress hormones through the measurement of awakening and diurnal profiles of salivary alpha-amylase (sAA) and cortisol concentrations.
Eating behaviors were assessed through three questionnaires (Eating Attitudes Test-26; Eating Disorders Inventory 2; and Body Shape Questionnaire), food intake by a 7-day diet record, and menstrual status by questionnaire. Perceived stress scale and anxiety state were also evaluated. Saliva samples were collected at awakening, 30 min, 60 min, and 12 hr post awakening after 6-days’ rest.
Forty-six percent of tennis players presented Disordered Eating attitudes (DE) (n = 12) with a lower body mass index, and higher state anxiety as compared with the group without DE. No differences in the Perceived Stress Scale scores were noted. Mean energy intake, protein and carbohydrates intakes were lower (p > .05) in the DE group as compared with the group without DE. Although in both groups, sAA concentrations presented a decrease in the first 30 min after awakening, and then progressively rose toward the afternoon, DE players exhibited reduced concentrations of the sAA with a decrease in its overall day secretion. Moreover, they showed a higher overall day secretion of salivary cortisol and a higher Cortisol Awakening Response.
These results suggest that the activity of the sympathetic nervous system is impaired whereas the cortisol awakening response is enhanced. The long-term consequences of these modifications on health remain to be elucidated.
Tarik Ozmen, Mert Aydogmus, Hanife Dogan, Derya Acar, Tuba Zoroglu and Mark Willems
Kinesio taping (KT) is a taping technique extensively used in rehabilitation of sports injuries; however, the effect of KT on delayed-onset muscle soreness is not entirely clear.
To investigate the effect of kinesio tape on the quadriceps femoris on muscle pain, flexibility, and sprint performance after squat exercise.
University research laboratory.
19 female university students (age 21.0 ± 1.2 y, weight 53.0 ± 4.6 kg, height 164 ± 4 cm).
Main Outcome Measures:
Pressure-pain threshold for quadriceps femoris was recorded using pressure algometry. Quadriceps femoris flexibility was measured as the range of motion of knee flexion with a stainless steel goniometer. Sprint-speed measurements were conducted using photocells placed at 0 and 20 m. All participants completed both conditions (KT application and no KT application) after a 1-wk washout period. Measurements were taken at baseline and 48 h postexercise. For the KT condition, KT was applied immediately before the exercise protocol and remained on the skin for 48 h.
Squat exercise reduced flexibility and increased pain and sprint time compared with baseline. KT application resulted in similar sprint time and muscle pain as the no-KT condition but maintained flexibility compared with baseline.
KT application immediately before squat exercise has no effect on muscle pain and short sprint performance but maintains muscle flexibility at 2 days of recovery.