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 < 0.05) in both exercise groups and was lower in BEX compared to MEX, while no differences were observed (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 < 0.05) post-training in BEX and MEX, whereas it did not differ (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.

Dietary Intake of Soccer Players before, during and after an Official Game: Influence of Competition Level and Playing Position.

Physical demands in soccer differ according to league level and playing position and may influence nutritional requirements. This study examined the effect of competition level and playing position on dietary intake in male soccer players (SP). Diet was weighed and recorded by 123 SP for 3 days; before, on the day, and the day after an official match. SP in the Super League (SL, n = 33) division reported higher (p < 0.05) average three-day energy (195 ± 36 kJ/kg), carbohydrate (6.0 ± 1.1 g/kg), and protein (2.2 ± 0.5 g/kg) intakes compared to the intakes reported by SP in the 2nd (n = 30) (energy: 159 ± 31 kJ/kg; carbohydrate: 4.6 ± 1.2 g/kg; protein: 1.9 ± 0.4 g/kg), 3rd (n = 30) (energy: 153 ± 34 kJ/kg; carbohydrate: 4.5 ± 1.2 g/kg; protein: 1.7 ± 0.4 g/kg), and 4th (n = 30) (energy: 152 ± 36 kJ/kg; carbohydrate: 4.2 ± 1.2 g/kg; protein: 1.7 ± 0.5 g/kg) national leagues (mean ± SD). Furthermore, when data were analyzed by playing position (pooled data), wide midfielders reported higher (p < 0.05) energy (183 ± 33 kJ/kg), carbohydrate (5.4 ± 1.2 g/kg), and fat (1.5 ± 0.4 g/kg) intakes compared to central defenders (energy: 147 ± 37 kJ/kg; carbohydrate: 4.1 ± 1.1 g/kg; fat: 1.2 ± 0.4 g/kg). The dietary intake of SP may differ according to the playing position and competition level, possibly due to different metabolic demands in training and competition.

Effect of a 36-Week Supervised Exercise Training Program on Physical and Cognitive Function in Older Patients With Dementia.

BACKGROUND/AIM: To investigate the effects of an exercise training program on physical and cognitive function in older patients with dementia. PATIENTS AND METHODS: Thirty-eight patients with early-middle dementia (31 females and seven males), aged 80.6±6.9 years, residents in an Elderly Care Unit, either completed a 36-week structured exercise program (Intervention Group, IG; n=19), or received the usual medical care (Control Group, CG; n=19). Before and after the 36-week intervention, cognitive function was evaluated in both groups by Mini-Mental State Examination (MMSE) and depression by Geriatric Depression Scale (GDS); physical function was assessed using handgrip test, Timed Up to Go (TUG), Berg Balance Scale (BBS) and Chair-Stand Test (CST), and daily living functionality by Functional Rating Scale for Symptoms of Dementia (FRSSD). RESULTS: As a result of exercise intervention, participants scored better in all functional and cognitive test assessments compared to the control group, as reflected by absolute and relative (%) differences in all metrics after the 36-week exercise program (p<0.001). CONCLUSION: A 36-week supervised exercise training program was found to result in significant improvements in physical and cognitive function of elderly patients in early to middle stages of dementia at an Elderly Care Unit. The promising results of this study shed more light on the adaptability of elderly patients with early and mild dementia to long-term exercise training and verified the feasibility of applying such programs in this clinical population.

The Effect of High-Intensity Interval Training on Mitochondrial-Associated Indices in Overweight and Obese Adults: A Systematic Review and Meta-Analysis.

BACKGROUND: Obesity is a significant health problem with an increasing incidence, causing a low-grade systemic inflammatory state and being implicated in various chronic diseases. Moreover, obesity has been shown to cause mitochondrial dysfunction through oxidative stress and inflammation, eventually affecting energy metabolism. However, high-intensity interval training (HIIT) can improve mitochondrial efficiency through exercise-induced mitochondrial adaptations. This systematic review and meta-analysis aims to examine the potential effects of HIIT on mitochondrial-associated indices in obese and overweight adults. METHODS: PubMed, Scopus, and Web of Science databases were searched. RESULTS: Twenty-eight eligible studies were included, involving 530 participants. HIIT was found to significantly improve the activity of citrate synthase (CS), cytochrome C (COX-IV), beta-hydroxyacyl CoA-dehydrogenase (ß-HAD), Complexes I-V as well as VO2max in overweight and obese individuals, whereas no significant changes were shown in PGC-1α and SIRT1. Interestingly, subgroup analyses revealed that CS, COX-IV, ß-HAD, and Complexes I-V activity exhibited a significant improvement only in the healthy subgroup. CONCLUSIONS: Overall, HIIT can be utilized to enhance mitochondrial-associated indices in overweight and obese individuals. However, this improvement may be health status dependent.

The Effects of a Short-Term Combined Exercise Program on Liver Steatosis Indices and the Lipidemic and Glycemic Profile in NAFLD Individuals: A Pilot Study.

Non-alcoholic fatty liver disease (NAFLD) is a very common liver disease associated with obesity, unhealthy diet, and lack of physical exercise. Short-term aerobic or resistance exercise has been shown to result in reduced liver fat in patients with NAFLD; however, the impact of the combination of these types of exercise has received less attention. This study investigated the effect of a short-term (7 days) concurrent exercise training program performed daily on liver steatosis indices, as well as the glycemic and lipidemic profile of overweight/obese sedentary volunteers. Twenty adult patients (age: 47.3 ± 12.3 yrs, body mass index: 32.4 ± 3.4 kg/m2) with NAFLD, detected by ultrasound and hematological indices, participated in the study. Pre- and post-exercise intervention assessment included body weight (BW), waist circumference (WC), hip/waist ratio (H/W), Homeostasis Model Assessment Insulin Resistance (HOMA-IR), blood lipids, and steatosis indices. Fatty Liver Index, Lipid Accumulation Index, WC, H/W, triglycerides, and total cholesterol were improved (p < 0.05) post-exercise, while no differences (p > 0.05) were observed in BW, HOMA-IR, HDL, LDL, Hepatic Steatosis Index, and Framingham Steatosis Index compared to pre-exercise values. It is concluded that a 7-day combined exercise program can have beneficial effects on hepatic steatosis and central adiposity indices, independently of weight loss, in patients with NAFLD.

Young Artistic Gymnasts Drink Ad Libitum Only Half of Their Fluid Lost during Training, but More Fluid Intake Does Not Influence Performance.

To examine the effect of the fluid balance on and performance in young artistic gymnasts during training under ad libitum and prescribed fluid intake conditions, eleven males (12.3 ± 2.6 years, mean ± SD) performed two 3 h identical training sessions. Participants ingested, in a random order, water equivalent to either 50% (LV) or 150% (HV) of their fluid loss. After the 3 h training, the gymnasts performed program routines on three apparatuses. The pre-exercise urine specific gravity (USG) was similar between conditions (LV: 1.018 ± 0.007 vs. HV: 1.015 ± 0.007; p = 0.09), while the post-exercise USG was lower in the HV condition (LV: 1.017 ± 0.006 vs. HV: 1.002 ± 0.003; p < 0.001). Fluid loss corresponding to percentage of body mass was higher in the LV condition (1.2 ± 0.5%) compared to the HV condition (0.4 ± 0.8%) (p = 0.02); however, the sums of the score performances were not different (LV: 26.17 ± 2.04 vs. HV: 26.05 ± 2.00; p = 0.57). Ingesting fluid equivalent to about 50% of the fluid lost, which was the amount that was drunk ad libitum during training, maintained short-term hydration levels and avoided excessive dehydration in artistic preadolescent and adolescent gymnasts. A higher amount of fluid, equivalent to about 1.5 times the fluid loss, did not provide an additional performance benefit.

Effects of Exercise and Physical Activity Levels on Childhood Cancer: An Umbrella Review.

Patients and survivors of childhood cancer experience adverse effects related to the disease and its treatment. These adverse effects are associated with both physiological and psychological health. Exercise helps manage the side effects and improve the health outcomes. The objective of this umbrella review is to search the current literature in the context of exercise and physical activity as complementary interventions on pediatric cancer and to provide comprehensive information about the derived health outcomes. A literature search was conducted on the Cochrane, PubMed, and Embase databases for systematic reviews published up to January 2023. Moreover, a hand search of reference lists was performed. We included participants under 19 years of age at diagnosis of any type of childhood cancer, without restriction on the type or phase of treatment, who participated in exercise interventions. The results showed a beneficial impact on fatigue, muscle strength, aerobic capacity, activity and participation levels, psychosocial health, cardiovascular/cardiorespiratory fitness, physical function, bone mineral density, and brain volume and structure, with limited and not serious adverse effects. These findings documented that exercise interventions had a positive effect on many physiological and psychological health outcomes in pediatric cancer patients and survivors.

The Role of Physical Exercise in Opioid Substitution Therapy: Mechanisms of Sequential Effects.

It is generally accepted that chronic opioid use is associated with structural and functional changes in the human brain that lead to an enhancement of impulsive behavior for immediate satisfaction. Interestingly, in recent years, physical exercise interventions have been used as an adjunctive treatment for patients with opioid use disorders (OUDs). Indeed, exercise has positive effects on both the biological and psychosocial basis of addiction, modifying neural circuits such as the reward, inhibition, and stress systems, and thus causing behavioral changes. This review focuses on the possible mechanisms that contribute to the beneficial effects of exercise on the treatment of OUDs, with emphasis placed on the description of a sequential consolidation of these mechanisms. Exercise is thought to act initially as a factor of internal activation and self-regulation and eventually as a factor of commitment. This approach suggests a sequential (temporal) consolidation of the functions of exercise in favor of gradual disengagement from addiction. Particularly, the sequence in which the exercise-induced mechanisms are consolidated follows the pattern of internal activation-self-regulation-commitment, eventually resulting in stimulation of the endocannabinoid and endogenous opioid systems. Additionally, this is accompanied by modification of molecular and behavioral aspects of opioid addiction. Overall, the neurobiological actions of exercise in combination with certain psychological mechanisms appear to promote its beneficial effects. Given the positive effects of exercise on both physical and mental health, exercise prescription is recommended as a complement to conventional therapy for patients on opioid maintenance treatment.

Vaccination coverage of primary care providers against seasonal influenza, tetanus, pneumococcal pneumonia and herpes zoster: A cross-sectional study in Greece.

Introduction: Primary care providers' (PCPs) compliance to self-immunization is important for their protection and the protection of their colleagues and patients and has been associated with the coverage of the general public. In this study, we aim to investigate the vaccination coverage of PCPs. Methods: A questionnaire-based cross-sectional survey was conducted among physicians, nurses and pharmacists employed in public or private primary care settings in Greece. Demographic and occupational characteristics as well as vaccination coverage data for influenza, tetanus, pneumococcal pneumonia and herpes zoster were collected. Statistical significance was set at 0.05. Results: In total, 748 (61.7% response rate) PCPs participated. Vaccination rates were 66.4% (496/747) for influenza (2019/2020 flu season), 62.9% (469/746) for tetanus (10-year Td or Tdap booster dose), 70% (14/20) for pneumococcal pneumonia (≥ 1 dose of PPSV23 or PCV13) and 12.3% (10/81) for herpes zoster. Multiple logistic regression revealed that nurses had significantly lower probability of being vaccinated against influenza [odds ratio (OR) = 0.25; 95% confidence interval (CI) = 0.14-0.45] and pharmacists had significantly lower probability of being vaccinated against both influenza (OR = 0.44; 95% CI = 0.31-0.62) and influenza & tetanus (OR = 0.52; 95% CI = 0.37-0.73) compared to physicians. Older age (>40 years) was an independent risk factor for not receiving a tetanus vaccine (40-49 vs. 19-39; OR = 0.42; 95% CI = 0.28-0.63, over 50 years old vs. 19-39; OR = 0.54; 95% CI = 0.36-0.79). Conclusions: The results revealed suboptimal vaccination rates among health providers who are in the frontline of adult immunization. Individualized and targeted measures to improve their vaccination coverage and indirectly the vaccination coverage of their patients, are therefore required.

The effectiveness of the active cycle of breathing technique in patients with chronic respiratory diseases: A systematic review.

BACKGROUND: Active cycle breathing technique (ACBT), which includes cycle of breathing control, thoracic expansion exercises and forced expiratory technique (FET), appears to have beneficial effects in patients with a variety of respiratory diseases. This systematic review provides an update on the new related studies, expanding the evidence base through the last 12 years and specifically evaluating the effectiveness of ACBT on pulmonary function-related outcome variables in patients with chronic respiratory diseases. METHODS: MEDLINE/Pubmed, PEDro, and Cochrane Library for Randomized Controlled Trials were searched between September 2008 and December 2021, in continuance of a previous systematic review, to identify randomized clinical trials and/or crossover studies comparing ACBT to other respiratory treatment techniques in patients with chronic obstructive pulmonary diseases, cystic fibrosis, or bronchiectasis. RESULTS: Eleven studies were included and the quality of most of them was moderate to good. The outcomes most frequently assessed were forced expiratory volume in 1 s (FEV1), sputum wet weight, forced vital capacity (FVC), and peak expiratory flow rate. Secondary outcomes were quality of life and dyspnea. Various comparators were identified and most of them assessed the ACBT as an effective method in comparison with other respiratory treatment modalities. Most studies revealed that ACBT/FET had at least an equally beneficial short-term effect on sputum wet weight, FEV1 and FVC compared to other treatment methods. CONCLUSION: The results of this updating review reinforced the data of a previous systematic review regarding the beneficial impact of ACBT for the short-term improvement in respiratory tract secretions clearance and pulmonary function. ACBT is effective in increasing the expectorated sputum volume, in reducing viscoelasticity of the secretion and in relieving symptoms such as dyspnea.

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.

The effects of exercise on VO2peak, quality of life and hospitalization in heart failure patients: A systematic review with meta-analyses.

Exercise training has become one of the most fundamental components of cardiac rehabilitation. This systematic review with meta-analyses has the objective to determine the effectiveness of exercise on selected cardiac rehabilitation outcomes, i.e. peak oxygen consumption (VO2peak), hospitalization and quality of life (QOL) of patients with heart failure. PubMed, EMBASE, and Cochrane Library were searched up to May 2019 to identify randomized controlled trials comparing exercise training to usual care. Overall, 131 trials were included with a total of 9,761 patients, the majority of whom were males (74%), predominantly with reduced ejection fraction and NYHA class ranging from II to III. There was a significant improvement in VO2peak in the exercise group compared to non-exercise control group (mean difference: 2.98 mL/kg/ min, 95% CI: 2.52-3.43, p < 0.001; 84 RCTs, n = 3,690 patients). Exercise training was also beneficial for the patients' QOL. The QOL meta-analysis included 5,786 patients and showed a clinically significant improvement of QOL following exercise (-0.82, 95% CI: -1.02 to -0.62; p = 0.00001; I2 = 91%). Hospitalization incidence of heart failure patients was also lower in the exercise compared to control group (fixed-effect Odds Ratio: 0.56, 95% CI: 0.42-0.75, p < 0.0001; 26 trials, 4,664 participants). Exercise-based rehabilitation improves V02peak and QOL and reduces the incidence of hospitalization of heart failure patients.

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

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<0.01), 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 ≤ 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<0.01). 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 a Carbohydrate-Electrolyte Solution on Fluid Balance and Performance at a Thermoneutral Environment in International-Level Fencers.

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.

Time Course of Oxidative Stress, Inflammation, and Muscle Damage Markers for 5 Days After a Soccer Match: Effects of Sex and Playing Position.

Souglis, A, Bogdanis, GC, Chryssanthopoulos, C, Apostolidis, N, and Geladas, ND. Time course of oxidative stress, inflammation and muscle damage markers for 5 days after a soccer match: Effects of sex and playing position. J Strength Cond Res 32(7): 2045-2054, 2018-This study examined the influence of sex and playing position on the time course of selected oxidative stress, inflammation, and muscle damage markers after an official soccer match. Sixty professional soccer players (30 men and 30 women) were divided into 3 groups, according to their playing position: defenders, midfielders, and attackers. Each group consisted of 10 male and 10 female players. Sixty healthy volunteers (30 men and 30 women) served as control. Blood samples were taken before and after the match and daily for 5 days after the match. Analysis of variance revealed different responses over time between sex and playing positions, as shown by the 3-way interaction, for creatine kinase (CK), protein carbonyls (PCs), catalase, fibrinogen, uric acid (UA), lactate dehydrogenase, reduced glutathione, C-reactive protein, and interleukin 6 (p < 0.01). Male players had higher values compared with women of the same playing position, for all oxidative, inflammatory, and muscle damage indices (p < 0.01). Also, in both sexes, midfielders had higher peaks in all indices compared with defenders (p < 0.05). Five days after the game CK and UA concentrations had not returned to pregame levels in any exercise group, whereas PCs were still elevated in male midfielders and attackers (p < 0.05). These results show that sex and playing position influence the time course of selected oxidative stress, inflammation, and muscle damage markers after an official soccer game. This information should be taken into account by practitioners for the design of training programs after match play.

Carbohydrate mouth rinse does not affect performance during a 60-min running race in women.

This study examined the effect of carbohydrate mouth rinsing on endurance running performance in women. Fifteen female recreational endurance runners, who used no oral contraceptives, ran two races of 1-h duration on an indoor track (216-m length) at 18:00 h after an 8-h fast with a 7-days interval between races, corresponding to the 3rd-10th day of each premenopausal runner's menstrual cycle, or any day for the postmenopausal runners. In a double-blind random order, participants rinsed their mouth with 25 ml of either a 6.4% carbohydrate (RCHO) or a placebo solution (RP). No fluid was ingested during exercise. Serum 17ß-Εstradiol (P = 0.59) and Progesterone (P = 0.35) did not differ between treatments. There was no difference in 1-hour running performance (RCHO: 10,621.88 ± 205.98 m vs. RP: 10,454.00 ± 206.64 m; t = 1.784, P = 0.096). Furthermore, the mean percentage effect (±99%CI) of RCHO relative to RP, 1.67% (-1.1% to 4.4%), and Cohen's effect size (d = 0.21) support a trivial outcome of RCHO for total distance covered. In conclusion, carbohydrate mouth rinsing did not improve 60-min track running performance in female recreational runners competing in a low ovarian hormone condition, after an 8-h fast and when no fluid was ingested during exercise.

Variability of performance during a 60-min running race.

The aim of the present study was to examine the variability of 1-h running performance outside the laboratory, under conditions simulating those of a real competitive event. Twenty-three male recreational runners performed on 3 occasions a 60-min simulated running race attempting to cover as long distance as possible. The races took place in an indoor track, in order to ensure stable environmental conditions. There was no difference in the distance covered between races (12,546.3 ± 217 m, 12,576 ± 219.1 m, 12,638.7 ± 225.3 m for the 1st, 2nd and 3rd races, respectively (mean ± S(X), F(2, 44) = 1.168, P = 0.32). The coefficient of variation for all participants was 1.5 ± 0.2 (range: 0.2-3.00). Multiple regression analysis indicated that 83% of the variability in best performance was predicted by determining the speed at the peak volume of oxygen uptake and body mass. In conclusion, performance during 1-h simulated running race in an indoor track was highly reproducible. The present study can be used as low-cost, time-efficient and ecologically valid tool, which could test simultaneously numerous runners' performance under conditions similar to real competitive events.

The effect of high vs. low carbohydrate diets on distances covered in soccer.

The purpose of this study was to compare the distances covered during a 11-a-side soccer match after players had consumed either a high carbohydrate (CHO) or a low CHO diet. Twenty-two male professional soccer players formed 2 teams (A and B), of similar age, body characteristics, and training experience. The 2 teams played against each other twice with a week interval between. For 3.5 days before the first match, the players of team A followed a high CHO diet that provided 8 g CHO per kg body mass (BM) (HC), whereas team B players followed a low CHO diet that provided 3 g CHO per kg BM (LC) for the same time period. Before the second match the dietary treatment was reversed and followed for the same time period. Training during the study was controlled, and distances covered were measured using global positioning system technology. Every player covered a greater total distance in HC compared with the distance covered in LC (HC: 9,380 ± 98 m vs. LC: 8,077 ± 109 m; p < 0.01). All distances covered from easy jogging (7.15 km·h-1) to sprinting (24.15 km·h-1) were also higher in HC compared with LC (p < 0.01). When players followed the HC treatment, they won the match (team A vs. team B: 3-1 for the first game and 1-2 for the second game). The HC diet probably helped players to cover a greater distance compared with LC. Soccer players should avoid eating a low (3 g CHO per kg BM) CHO diet 3-4 days before an important soccer match and have a high CHO intake that provides at least 8 g CHO per kg BM.

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

The purpose of this study was to examine the influence of a carbohydrate-rich meal on post-prandial metabolic responses and skeletal muscle glycogen concentration. After an overnight fast, eight male recreational/club endurance runners ingested a carbohydrate (CHO) meal (2.5 g CHO x kg(-1) body mass) and biopsies were obtained from the vastus lateralis muscle before and 3 h after the meal. Ingestion of the meal resulted in a 10.6 +/- 2.5% (P < 0.05) increase in muscle glycogen concentration (pre-meal vs post-meal: 314.0 +/- 33.9 vs 347.3 +/- 31.3 mmol x kg(-1) dry weight). Three hours after ingestion, mean serum insulin concentrations had not returned to pre-feeding values (0 min vs 180 min: 45 +/- 4 vs 143 +/- 21 pmol x l(-1)). On a separate occasion, six similar individuals ingested the meal or fasted for a further 3 h during which time expired air samples were collected to estimate the amount of carbohydrate oxidized over the 3 h post-prandial period. It was estimated that about 20% of the carbohydrate consumed was converted into muscle glycogen, and about 12 % was oxidized. We conclude that a meal providing 2.5 g CHO x kg(-1) body mass can increase muscle glycogen stores 3 h after ingestion. However, an estimated 67% of the carbohydrate ingested was unaccounted for and this may have been stored as liver glycogen and/or still be in the gastrointestinal tract.

The effect of a high carbohydrate meal on endurance running capacity.

This study examined the effects of a pre-exercise meal and a carbohydrate-electrolyte solution on endurance running capacity. Ten men performed 3 treadmill runs at 70% VO2max to exhaustion after consuming (a) a carbohydrate meal 3 h before exercise and a carbohydrate-electrolyte solution during exercise (M + C); or (b) the carbohydrate meal 3 h before exercise and water during exercise (M + W); or (c) a liquid placebo 3 h before exercise and water during exercise (P + W). Exercise time was longer in M + C (125.1 +/- 5.3 min; mean +/- SE) and M + W (111.9 +/- 5.6 min) compared with P + W (102.9 +/- 7.9 min; p < .01 and p < .05, respectively), and longer in M + C compared with M + W (p < .05). Serum insulin concentration at the start of exercise and carbohydrate oxidation rates during the first hour of exercise were higher, whereas plasma FFA concentrations throughout exercise were lower in M + W and M + C than in P + W (p < .01). A carbohydrate meal before exercise at 70% VO2max improved endurance running capacity; however, the combination of the meal and a carbohydrate-electrolyte solution during exercise further improved endurance running capacity.