THURSDAY , MAY 3 0 , 2 0 19 D-08 Thematic Poster
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Official Journal of the American College of Sports Medicine Vol. 51 No. 5 Supplement S343 D-08 Thematic Poster - Female and Sex-Specific each sex, α=0.05. Pre-planned contrast comparisons determined sex differences at each time point, α=0.01. RESULTS: Soleus and gastrocnemius masses presented Physiology lower at 24h in female (-11.8%, -9%; p<0.05) and 48h in male (-16%, -13%; p<0.05) Thursday, May 30, 2019, 1:30 PM - 3:30 PM compared to control. In predominantly type I soleus, Pgc-1α4 mRNA content showed Room: CC-104B a decline from control across time in females, while spiking >9, >6-fold in males at 72h and 168h (p<0.05). In contrast, IGF-1 showed higher content in females at 72h and 168h (+77%, +27%; p<0.05) than males. In gastrocnemius, a more mixed fiber type, Pgc-1α4 content was 3-fold higher in females at 24h (p<0.05). Female IGF-1 1586 Chair: Saori Hanaki. Weber State University, Ogden, UT. content was significantly elevated compared to male at 72h (p<0.05). Deptor content in (No relevant relationships reported) gastrocnemius was >3-fold from baseline at 24h in females and >2-fold from baseline at 48h in males (p<0.05) depicting the only mRNA content change aligning with the observed time course for appearance of loss in muscle mass. CONCLUSION: 1587 Board #1 May 30 1:30 PM - 3:30 PM Anabolic regulator responses to atrophic stimuli differ across sex, muscle tissue and time course of muscle atrophy. These early findings could suggest Deptor as a novel Role Of Gender In Anti-oxidant Response To A Bout Of therapeutic target to ameliorate muscle wasting conditions. Aerobic Exercise In Healthy Adults Supported by NIH Grant R15 AR069913/AR/NIAMS.Sponsoring Fellow: Stavros A. Anam Ahmad1, Zoe Morris1, Lisa M.K. Chin1, Rebekah Feng1, Kavouras; [email protected] Leo Saligan1, Leighton Chan1, Randall Keyser, FACSM2. 1National Institutes of Health, Bethesda, MD. 2George Mason 1589 Board #3 May 30 1:30 PM - 3:30 PM University, Fairfax, VA. Similar Central and Peripheral Fatigue in Men and Email: [email protected] Women after Running (No relevant relationships reported) Beth W. Glace, Ian J. Kremenic, Malachy P. McHugh, FACSM. Nicholas Inst. of Sports Med. and Athletic Trauma, Lenox Hill Aerobic exercise acutely increases the production of reactive oxygen species (ROS), Hosp., New York, NY. (Sponsor: Malachy P. McHugh, FACSM) which creates an imbalance between free radicals and the body’s antioxidant defenses, Email: [email protected] resulting in increased oxidative stress. Oxidative stress levels are reportedly higher in males compared to females, however there is limited knowledge regarding the role (No relevant relationships reported) of gender in the antioxidant response following an acute bout of aerobic exercise. Purpose: To determine whether changes in serum antioxidant levels after an acute PURPOSE: Women may be less fatiguable than men during prolonged endurance aerobic exercise bout differed between genders.Methods : The study comprised of 15 exercise. There are a paucity of studies which have compared fatigue in both sexes healthy adults (9 females, 6 males; age 27±8 years; BMI 24±3 kg/m2) enrolled in the after moderately long duration running typical of marathon-type training. METHODS: NIH Fatigue in Healthy Individuals Protocol (NCT00888563). During the first visit, We compared sex differences in peripheral and central fatigue in 8 men and 6 subjects completed a treadmill cardiopulmonary exercise test (CPET) to volitional premenopausal women runners. Volunteers [38±2 and 32±2 yrs, p=0.017; VO2peak exhaustion. On a separate visit, subjects performed a vigorous-intensity continuous 59±3 and 54±3, ml/kg/min, p=0.202, men vs women respectively] ate a standardized work rate (WR) test, to volitional exhaustion on the treadmill. Serum samples were breakfast [6 Kcal/kg] 90 minutes prior to commencing testing. Water was provided collected before and immediately after the vigorous exercise bout. A Human Oxidative at 1% of body mass/hr, during a 2-hr run at their ventilatory threshold [~65% Stress Multiplex panel was used to determine serum peroxidase (PRX2) and catalase VO2peak], followed by a self-paced 2-km time trial. RPE and respiratory measures levels. Student’s t-tests were performed between genders for WR and antioxidant were determined every 20 minutes. Strength was tested in a semi-reclined position levels. Results: Males performed vigorous-intensity exercise at a higher WR than [75o hip flexion, to facilitate femoral nerve stimulation] pre-exercise, after the 2-hr females (p<0.0001). No difference was found in baseline PRX2 and catalase levels run and post-time trial as follows: voluntary isometric quad strength was measured between males and females. Relative change in PRX2 (+32% in males; -17% in on the Biodex with the knee flexed 60°, and with superimposed peripheral magnetic females) and catalase (+18% in males; -11% in females) was different between genders stimulation [PMS] of the femoral nerve to determine central activation [CAR]. PMS after a vigorous bout of aerobic exercise (p=0.0136, p=0.0344, respectively). This was also applied in a 3-second pulse train on a relaxed muscle to measure peripheral 30, 2019 MAY THURSDAY, difference became insignificant when WR was accounted for.Conclusion : This study fatigue. Changes in strength and in metabolic measures were analyzed with repeated suggests that higher levels of oxidative stress in males may be explained by higher measures ANOVA. work rates. However, response to exercise-induced oxidative stress demonstrated RESULTS: Following running, voluntary strength declined by ~16% in both sexes that males (6 of 6) increased anti-oxidant levels, while females (8 out of 9) showed [effect of time p<0.001; sex X time p=0.206]. CAR also decreased in both men and decreased levels. Previous studies have suggested that gender differences in oxidative women [effect of time p=0.020, time X sex p=0.762]. PMS-stimulated forces, our stress may be related to an increased production of ROS by NADPH-oxidase in males, measure of peripheral fatigue, were unchanged after running: there was no effect of or antioxidant properties of estrogen which may assist in minimizing oxidative stress time [p=0.10] in men or women [time X sex, p=0.322]. Substrate use and RPEs did not in females. differ between sexes. Funding: National Institute of Nursing Research, Division of Intramural Research CONCLUSIONS: We found that both sexes fatigued similarly after a 2-hr run plus a 2-km time trial, and that all of the fatigue was central in nature. While women may be 1588 Board #2 May 30 1:30 PM - 3:30 PM more fatigue-resistant than men, those differences might not be apparent until a greater duration of running is engaged in, e.g. ultramarathon distances. Sex Differences in Anabolic Regulators during Development of Atrophic Pathology in Hindlimb- 1590 Board #4 May 30 1:30 PM - 3:30 PM Unloading-Induced Disuse The Effects Of Swimming On Bone Density In Female 1 1 1 Lisa T. Jansen , Megan E. Rosa-Caldwell , Wesley S. Haynie , Collegiate Swimmers. Seongkyun Lim1, Kirsten Dunlap1, Jacob L. Brown1, David E. Lee1, Richard A. Perry1, Michael P. Wiggs2, Tyrone A. Margaret Miller, Sarah Kojetin, Lesley M. Scibora. University of Washington1, Nicholas P. Greene1. 1University of Arkansas, St. Thomas, St. Paul, MN. Fayetteville, AR. 2University of Texas at Tyler, Tyler, TX. (No relevant relationships reported) (Sponsor: Stavros A. Kavouras, FACSM) Email: [email protected] Swimming provides numerous health benefits, but as a non-weight bearing activity research suggests it provides no constructive benefits on bone strength at dual energy (No relevant relationships reported) x-ray absorptiometry (DXA)-measured hip and lumbar spine sites. However, little research has focused on skeletal sites stressed during swimming such as the upper arm. Muscle atrophy is a comorbidity in many disease conditions, contributing to Purpose: To determine potential site-specific bone strength adaptations at the humerus accelerated disease progression/terminal outcomes. Muscle wasting results alterations among collegiate swimmers compared to sedentary controls. in the ratio of protein synthesis to degradation, with wasting conditions favoring Methods: degradation. Atrophic conditions differentially affect discrete muscle types. For Bone geometry and strength were assessed by peripheral quantitative computed many diseases, onset and progression of muscle atrophy presents differently between tomography (pQCT) in ten collegiate female swimmers (BMI 23 kg/m2; mean muscle fiber types and sex;PURPOSE : To assess gene content outcomes of three 13.9±1.5 pool hours/week) and ten sedentary controls (BMI 24 kg/m2; <150 minutes/ established anabolic regulators Pgc-1α4, IGF-1, and Deptor, in female and male week of physical activity) ages 18-23 years. Total volumetric bone mineral density mice during initiation and progression of disuse atrophy across multiple fiber types. (vBMD, mg/mm3) and total bone area (ToA, mm2) were assessed at the distal (4%) METHODS: 100 female and male C57BL/6J mice were hindlimb unloaded for 0h, tibia. Cortical bone area (CoA, mm2), cortical density (vBMD), cortical thickness 24h, 48, 72 and 168h, to induce muscle atrophy. At assigned endpoints, soleus and gastrocnemius muscles were excised and processed for mRNA analysis of Pgc-1α4, IGF-1, and Deptor using RT-PCR. Data were analyzed by one-way ANOVA within Abstracts were prepared by the authors and printed as submitted. ® S344 Vol. 51 No. 5 Supplement MEDICINE & SCIENCE IN SPORTS & EXERCISE 3 (CoTh, mm), bone bending strength (polar strength-strain index (SSIp, mm ) were after task failure for a total of 6 sets. The last two MVC, VA, and Qtw were averaged measured at the midshaft (66%) tibia, humerus (50%), and radius 33% sites.