Effect of a Carbohydrate-Electrolyte Solution on Fluid Balance and Performance at a Thermoneutral Environment in International-Level Fencers

© 2019 by the National Strength & Conditioning Association.Chryssanthopoulos, C, Tsolakis, C, Bottoms, L, Toubekis, A, Zacharogiannis, E, Pafili, Z, and Maridaki, M. Effect of a carbohydrate-electrolyte solution on fluid balance and performance at a thermoneutral environment in international-level fencers. J Strength Cond Res 34(1): 152-161, 2020-The purpose of the study was to examine a possible effect of a carbohydrate-electrolyte (CHO-E) solution on fluid balance and performance in fencing at a thermoneutral environment. Sixteen fencers performed two 120-minute training sessions separated by 7-14 days under similar environmental conditions (temperature: 20.3° C and humidity: 45-47%). Each session consisted of 60-minute conditioning exercises followed by 10 bouts of 3 minutes against the same opponent with 3-minute interval between each bout. Participants ingested at regular intervals either a 6% CHO-E solution or an artificially sweetened water (PL) in a counterbalanced order. No difference was observed between conditions in the heart rate responses, perceived exertion, changes in plasma volume, urine specific gravity, number of bouts won or lost, or points for and against. Considerable variability was observed in body mass changes that revealed significant differences at the time level (i.e., pre- vs. post-exercise) (F1,15 = 9.31, p = 0.008, η = 0.38), whereas no difference was found between conditions (i.e., CHO-E vs. PL) (F1,15 = 0.43, p = 0.52, η = 0.03) and conditions × time interaction (F1,15 = 3.57, p = 0.078, η = 0.19). Fluid loss was not significantly different between conditions (p = 0.08, d = 0.47). The blood glucose level was higher (p < 0.01) after exercise in CHO-E, whereas the blood lactate level was similar between conditions. In conclusion, the CHO-E solution was as effective as the artificially sweetened water in terms of fluid balance and fencing performance at a thermoneutral environment. Because of large individual variability, fencers should monitor their fluid intake and body fluid loss in training and competition.Peer reviewedFinal Accepted Versio

Pre-Exercise Maltodextrin Ingestion and Transient Hypoglycemia in Cycling and Running

International Journal of Exercise Science 13(2): 1691-1704, 2020. This study examined the phenomenon of transient hypoglycemia and metabolic responses to pre-exercise carbohydrate (CHO) maltodextrin ingestion in cycling and running on the same individuals. Eleven active males cycled or ran for 30 min at 80% maximal heart rate (HRmax) after ingestion of either 1g/kg body mass maltodextrin (CHO-Cycle and CHO-Run respectively) or placebo (PL-Cycle and PL-Run) solutions. Fluids were ingested 30min before exercise in a double-blind and random manner.Blood glucose and serum insulin were higher before exercise in CHO (mean CHO-Cycle+CHO-Run) (Glucose: 7.4 ± 0.3 mmol.l-1; Insulin: 59 ± 10 mU.l-1) compared to placebo (mean PL-Cycle+PL-Run) (Glucose: 4.7 ± 0.1 mmol.l-1; Insulin: 8 ± 1 mU.l-1) (p\u3c0.01), but no differences were observed during exercise among the 4 conditions. Mean blood glucose did not drop below 4.1 mmol.l-1 in any trial. However, six volunteers in CHO-Cycle and seven in CHO-Run experienced blood glucose concentration \u3c 3.5 mmol.l-1 at 20min of exercise and similar degree of transient hypoglycemia in both exercise modes. No association was found between insulin response to maltodextrin ingestion and drop in blood glucose during exercise. Blood lactate increased with exercise more in cycling compared to running, and plasma free fatty acids (FFA) concentrations were higher in placebo compared to CHO irrespective of exercise mode (p\u3c0.01). The ingestion of maltodextrin 30min before exercise at about 80% HRmax produced similar glucose and insulin responses in cycling and running in active males. Lactate was higher in cycling, whereas maltodextrin reduced FFA concentrations independently of exercise mode

Effect of performance standard and sex on 24 h ultra-marathon pacing profiles

The purpose of the present study was to examine the effect of sex and performance standard on pacing profiles in a 24 h ultra-marathon race. Performance data of 283 participants (237 men and 46women) from the last decade’s versions (2011 until 2020, with the exception of the 2017 version) of the International Ultramarathon Festival held in Athens-Hellinikon, Greece, were analyzed and pacing profiles were evaluated based on performance standard and sex. Relative speed for every hour and % distance covered in 6 h and 12 h segments and coefficient of variation (CV) were calculated. Mean distance ran was 159.99 +/- 36.04 km. Runners followed a reverse J-shaped race pace (p &lt; 0.001). Sex did not seem to interact with pacing (p &gt; 0.05 in every case), while performance standard interacted significantly with pacing (p &lt; 0.001). CV was negatively correlated with total distance covered and total running time (-0.761, p &lt; 0.001 and -0.753, p &lt; 0.001, respectively). In conclusion, the overall pacing profile adopted by runners in a 24 h ultra-marathon race was a reverse J-shaped model, with better runners following a more even pacing than slower runners, with lower velocity variability

Skeletal muscle glycogen concentration and metabolic responses following a high glycaemic carbohydrate breakfast.

Etude effectuée chez des coureurs d'endurance. Influence d'un repas très riche en glucides sur la concentration de glycogène musculaire 3 heures après son ingestion

Effects of a Two-Month Exercise Training Program on Concurrent Non-Opiate Substance Use in Opioid-Dependent Patients during Substitution Treatment

Background: This randomized controlled trial aimed to evaluate the effects of a two-month exercise intervention on the concurrent non-opiate substance use (alcohol, cocaine, cannabis, and benzodiazepines) in opioid users during their medication treatment. Methods: Ninety opioid users (41 females) in methadone and buprenorphine medication treatment were randomly divided into four groups: (a) buprenorphine experimental (BEX; n = 26, aged 41.9 ± 6.1 yrs); (b) buprenorphine control (BCON; n = 25, aged 41.9 ± 5.6 yrs); (c) methadone experimental (MEX; n = 20, aged 46.7 ± 6.6 yrs); and (d) methadone control (MCON; n = 19, aged 46.1 ± 7.5 yrs). The experimental groups (BEX and MEX) followed an aerobic exercise training program on a treadmill for 20 min at 70% HRmax, 3 days/week for 8 weeks. Socio-demographic, anthropometric, and clinical characteristics, as well as non-opioid drug use in days and quantity per week, were assessed before and after the intervention period. Results: Following the exercise training, the weekly non-opioid substance consumption (days) decreased (p p > 0.05) between the control groups (BCON vs. MCON) or compared to their baseline levels. Similarly, the daily amount of non-opiate substance intake was reduced (p p > 0.05) in BCON and MCON compared to the baseline. Conclusions: The two-month exercise intervention reduced the non-opioid drug use in both the methadone and buprenorphine substitution groups compared to the controls, suggesting that aerobic exercise training may be an effective strategy for treating patients with OUDs

Impact of supervised aerobic exercise on clinical physiological and mental parameters of people living with HIV: a systematic review and meta-analyses of randomized controlled trials

Background: The benefits derived from supervised aerobic exercise in people living with human immunofeficiency virus– HIV (PLWH) have not yet been clearly identified. Objective: To evaluate the impact of supervised aerobic exercise on immunological, cardiorespiratory, pulmonary, hemodynamic and mental parameters of PLWH. Methods: A systematic review was carried out in accordance to PRISMA guidelines. PubMed, Physiotherapy Evidence Database (PEDro) and Cochrane Central Register of Controlled Trials (CENTRAL) were screened up to August 2021, for the identification of English written randomized trials, with participants aged 18 years and older, at any stage of the disease, with or without co-morbidities. The risk of bias assessment was conducted according to the Cochrane Collaboration’s tool for assessing risk of bias. Meta- analyses were conducted using continuous, inverse variance, random-effects model. Results: Ten studies were suitable for meta-analysis based on inclusion criteria. Supervised aerobic exercise appeared to have beneficial effects on depressive symptoms [mean difference (MD)= −4.18 (confidence interval (CI)= (−6.55)–(−1.81), Z = 3.46, p = 0.0005, I2=0%, n = 2], forced expiratory volume in 1 sec [MD = 0.70, CI = 0.39–1.00, Z = 4.41, p < 0.0001, I2=0%, n = 2], and on the maximum oxygen uptake [MD = 1.38, CI = −0.02–2.78, Z = 1.94, p = 0.05, I2=94%, n = 4] of PLWH. No exercise effect was found for CD4 T-cell count (p = 0.16, n = 5), systolic blood pressure (p = 0.91, n = 2) and diastolic blood pressure (p = 0.72, n = 2). Conclusions: Supervised continuous aerobic exercise may improve lung function, depressive symptomatology and aerobic capacity of PLWH, however, the small number of available studies and the high heterogeneity concerning VO2max demonstrate the need for more research in this area