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 Role of Exercise in Cancer-Related Sarcopenia and Sarcopenic Obesity

One of the most common adverse effects of cancer and its therapeutic strategies is sarcopenia, a condition which is characterised by excess muscle wasting and muscle strength loss due to the disrupted muscle homeostasis. Moreover, cancer-related sarcopenia may be combined with the increased deposition of fat mass, a syndrome called cancer-associated sarcopenic obesity. Both clinical conditions have significant clinical importance and can predict disease progression and survival. A growing body of evidence supports the claim that physical exercise is a safe and effective complementary therapy for oncology patients which can limit the cancer- and its treatment-related muscle catabolism and promote the maintenance of muscle mass. Moreover, even after the onset of sarcopenia, exercise interventions can counterbalance the muscle mass loss and improve the clinical appearance and quality of life of cancer patients. The aim of this narrative review was to describe the various pathophysiological mechanisms, such as protein synthesis, mitochondrial function, inflammatory response, and the hypothalamic-pituitary-adrenal axis, which are regulated by exercise and contribute to the management of sarcopenia and sarcopenic obesity. Moreover, myokines, factors produced by and released from exercising muscles, are being discussed as they appear to play an important role in mediating the beneficial effects of exercise against sarcopenia.

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.

The Effect of a Home-Based Tele-Exercise Training Program on the Quality of Life and Physical Performance in Breast Cancer Survivors

The number of breast cancer (BCa) survivors has been steadily increasing due to advances in anti-cancer treatments, though these individuals suffer from various cancer- and treatment-related long-term side effects. The present study aimed at investigating the effects of a home-based tele-exercise training intervention on physical- and mental health-associated parameters in BCa survivors. A total of 13 female BCa survivors (age: 58.31 ± 3.13 years, BMI: 25.68 ± 0.62 kg/m², waist circumference: 96.54 ± 1.84 cm) participated in a two-month group tele-exercise program twice per week which included aerobic, resistance and flexibility exercises. The results of the study revealed that the tele-exercise intervention improved participants' body mass index (BMI) (p < 0.001), waist circumference (p < 0.001), cardiorespiratory fitness (6 min walk test) (p < 0.001) and muscle function (sit to stand (p < 0.01), sit ups (p < 0.001) and push-ups (p < 0.001)). Beneficial effects were also observed on perceived anxiety (Zung Self-Rating Anxiety Scale) (p < 0.001), post-traumatic stress disorder (PTSD) symptoms (PCL-C) (p < 0.01), self-reported fatigue (p < 0.001), quality of life (QoL) (p < 0.05) and physical (p < 0.05), cognitive (p < 0.01) and emotional (p < 0.05) functioning (EORTQ-QLQ-C30). Our findings suggest that common cancer- and treatment-related adverse effects on physical performance, mental health and the overall QoL can be ameliorated through tele-exercise training programs in BCa survivors.

The Role of Mitophagy in Skeletal Muscle Damage and Regeneration

Mitochondria are cellular organelles that play an essential role in generating the chemical energy needed for the biochemical reactions in cells. Mitochondrial biogenesis, i.e., de novo mitochondria formation, results in enhanced cellular respiration, metabolic processes, and ATP generation, while autophagic clearance of mitochondria (mitophagy) is required to remove damaged or useless mitochondria. The balance between the opposing processes of mitochondrial biogenesis and mitophagy is highly regulated and crucial for the maintenance of the number and function of mitochondria as well as for the cellular homeostasis and adaptations to metabolic demands and extracellular stimuli. In skeletal muscle, mitochondria are essential for maintaining energy homeostasis, and the mitochondrial network exhibits complex behaviors and undergoes dynamic remodeling in response to various conditions and pathologies characterized by changes in muscle cell structure and metabolism, such as exercise, muscle damage, and myopathies. In particular, the involvement of mitochondrial remodeling in mediating skeletal muscle regeneration following damage has received increased attention, as modifications in mitophagy-related signals arise from exercise, while variations in mitochondrial restructuring pathways can lead to partial regeneration and impaired muscle function. Muscle regeneration (through myogenesis) following exercise-induced damage is characterized by a highly regulated, rapid turnover of poor-functioning mitochondria, permitting the synthesis of better-functioning mitochondria to occur. Nevertheless, essential aspects of mitochondrial remodeling during muscle regeneration remain poorly understood and warrant further characterization. In this review, we focus on the critical role of mitophagy for proper muscle cell regeneration following damage, highlighting the molecular mechanisms of the mitophagy-associated mitochondrial dynamics and network reformation.

Physical Exercise Restrains Cancer Progression through Muscle-Derived Factors

Simple Summary

The benefits of physical exercise against cancer onset and progression, as well as the adverse effects of physical inactivity have changed the way that we utilize exercise for cancer patients. Nevertheless, although guidelines of various scientific societies and organizations propose exercise as a complementary intervention during cancer therapies, the exact cellular and molecular mechanisms by which exercise acts against cancer have not yet been elucidated. In the present review, we analyze the factors which either are secreted from skeletal muscle or are regulated by exercise and can restrain cancer evolution. We also describe the exercise-induced factors that counteract severe side effects of cancer treatment, as well as the ways that muscle-derived factors are delivered to the target cells.

Abstract

A growing body of in vitro and in vivo studies suggests that physical activity offers important benefits against cancer, in terms of both prevention and treatment. However, the exact mechanisms implicated in the anticancer effects of exercise remain to be further elucidated. Muscle-secreted factors in response to contraction have been proposed to mediate the physical exercise-induced beneficial effects and be responsible for the inter-tissue communications. Specifically, myokines and microRNAs (miRNAs) constitute the most studied components of the skeletal muscle secretome that appear to affect the malignancy, either directly by possessing antioncogenic properties, or indirectly by mobilizing the antitumor immune responses. Moreover, some of these factors are capable of mitigating serious, disease-associated adverse effects that deteriorate patients’ quality of life and prognosis. The present review summarizes the myokines and miRNAs that may have potent anticancer properties and the expression of which is induced by physical exercise, while the mechanisms of secretion and intercellular transportation of these factors are also discussed.

Oxygen Uptake in Repeated Cycling Sprints Against Different Loads Is Comparable Between Men and Preadolescent Boys

Children recover faster than adults in repeated sprints, but it is unclear if their aerobic responses differ.

Purpose

This study tested the hypothesis that aerobic response (VO2) during repeated sprints is greater in preadolescent boys than in men. Further, this study compared normalization with conventional ratio-scaling and scaling with the use of body mass (BM) as a covariate.

Methods

Nine boys (age: 11.8 ± 0.6 years, swimmers) and 11 men (age: 21.7 ± 0.6 years, recreational athletes) performed 10 maximal 6-s cycling sprints separated by 24-s of passive recovery, against two loads (optimum and 50% of optimum). Oxygen uptake (VO2) was measured continuously.

Results

Men’s mean power output (MPO) was greater than boys in each sprint, both in absolute (unscaled) values ( p &lt; 0.05) and when adjusted for lean leg volume ( p &lt; 0.05). Children had lower absolute VO2 ( p &lt; 0.05) than men, but when it was adjusted for BM or power-output, VO2 was comparable between men and boys. Thus, most of the difference in VO2 between men and boys was due to body size and power-output differences.

Conclusion

Our results suggest that men and boys have similar VO2 during repeated sprints when appropriately adjusted to body mass or power output. Results highlight the importance of using appropriate scaling methods to compare adults’ and children’s aerobic responses to high-intensity exercise.

Expression of tissue remodelling, inflammation- and angiogenesis-related factors after eccentric exercise in humans

Eccentric exercise has been extensively used as a model to study the contraction-induced muscle damage and its consequent processes. This study aimed at examining molecular responses associated with tissue remodelling, inflammation and angiogenesis in skeletal muscle during the recovery period after eccentric exercise in humans. Ten healthy men performed 50 maximal eccentric muscle actions with the knee extensors and muscle biopsies were collected from the vastus lateralis before and 6 h, 48 h and 120 h post eccentric exercise. Real Time-PCR was utilized to investigate alterations in gene expression of various tissue remodelling-, inflammation- and angiogenesis-related factors: uPA, uPA-R, TGF-β1, MMP-9, TNF-α, IL-6, IL-8, VEGF, VEGFR-2, HIF-1a, Ang-1, Ang-2 and Tie-2. The uPA/uPA-R system exhibited a similar time-expression pattern increasing 6 h post exercise (p < 0.05), while the other tissue remodelling factors TGF-β1 and MMP-9 did not change significantly over time. Transcriptional responses of inflammatory factors TNF-α and IL-8 increased significantly and peaked 6 h post eccentric exercise (p < 0.05), while IL-6 exhibited a similar, though not statistically significant, expression profile (p > 0.05). Similarly, the expression of angiopoietin receptor Tie-2 showed an early increase only at 6 h after the completion of exercise (p < 0.05), while the other angiogenic factors failed to reach statistical significance due a high interindividual variability in the gene expression responses. The early transcriptional upregulation of tissue remodelling, inflammation- and angiogenesis-related factors post eccentric exercise may indicate the acute intramuscular activation of these processes functionally related to muscle damage-induced adaptation.

Acute and delayed hormonal and blood cell count responses to high-intensity exercise before and after short-term high-intensity interval training

The acute and delayed hormonal and blood cell responses to a high-intensity interval training (HIIT) session, were examined before and after a 3-week intervention (9 HIIT sessions of 4-6 × 30 s high-intensity cycling bouts) in eight recreationally active male volunteers (age: 24.3 ± 1.4 y, VO₂max: 41.2 ± 3.2 ml/kg/min). Blood samples were collected before and 0.5, 24, 48 h following the first and last training session. Before training, the HIIT session induced acute increases in cortisol, prolactin and TSH concentration, while free-T4 peaked 24 h later (p < 0.001) and testosterone remained unchanged. White blood cell count was increased 0.5 h after exercise (p < 0.001), while lymphocyte percentage decreased 24 h post exercise (p < 0.01). After three weeks of HIIT, cortisol, WBC and lymphocyte responses were decreased by ~42% (p = 0.002), 8.6% (p = 0.032) and 9.6% (p = 0.039), respectively, despite an increase in total work. These findings show that short-term HIIT may induce rapid adaptations of the hypothalamic-pituitary-adrenal axis and may blunt exercise-induced immune responses.

Physiological Adaptations to High-Intensity Interval and Continuous Training in Kayak Athletes

Papandreou, A, Philippou, A, Zacharogiannis, E, and Maridaki, M. Physiological adaptations to high-intensity interval and continuous training in kayak athletes. J Strength Cond Res 34(8): 2258-2266, 2020-High-intensity interval training (HIIT) seems to be more effective than continuous training (CT) for the improvement of physical condition and sports performance. This study compared physiological adaptations with HIIT and CT in flat water kayak athletes. Twenty-four national-class kayakists were divided into 3 groups (n = 8 per group), 2 of which participated in an 8-week CT or HIIT program, whereas the third one served as control (C). An incremental maximum oxygen uptake (V[Combining Dot Above]O2max), a maximal anaerobic Wingate-type, as well as 1,000-m (T1,000 m) and 200-m (T200 m) time test were performed before and after the training period on a kayak ergometer, to determine changes in V[Combining Dot Above]O2max, peak blood lactate ([La]peak), paddling speed at V[Combining Dot Above]O2max ((Equation is included in full-text article.)), heart rate at V[Combining Dot Above]O2max (HRpeak), paddling economy speed (PEs; speed at 75% of V[Combining Dot Above]O2max), paddling speed at anaerobic ventilatory threshold (PSVT2), maximal paddling speed (PSpeak), and reduction of PSpeak (PSR). V[Combining Dot Above]O2max, [La]peak, HRpeak, and PSR did not change after the 8-week training compared with baseline in either training group (p > 0.05). However, significant changes were found in PSVT2 and T200 m (HIIT), (Equation is included in full-text article.), PEs, PSpeak, and T1,000 m (CT and HIIT) (p < 0.05-0.0001) as compared to baseline. Moreover, percent changes were different between the training groups in PEs, and between control and training groups in PSpeak and (Equation is included in full-text article.)(p < 0.05-0.01). Both training programs improved physiological and performance variables; however, HIIT resulted in significant changes of PSVT2 and T200 m and higher improvement of PEs with 15 times less training time compared with CT. Thus, HIIT seems more time-efficient than CT for improving paddling economy of kayaking performance.

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.

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.

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.

THE EFFECT OF 6-WEEKS WHOLE BODY VIBRATION ON MUSCULAR PERFORMANCE ON YOUNG NON-COMPETITIVE FEMALE ARTISTIC GYMNASTS

The purpose of this study was to investigate the effects of a 6-week whole body vibration-intervention on muscle performance and flexibility on gymnasts. Twenty-two young non-competitive-moderate trained gymnasts that volunteered to participate in the study separated into either the vibration group or the no vibration group according to their training regime. The vibration intervention consisted of a 6-week whole-body vibration, 3 times per week and involved eccentric and concentric squatting movements on a vibration platform with the participants performing three exercises on the vibration device whereas for the no vibration group vibration platform was turned off. Five performance tests (20m running speed, sit & reach test, squat jump, counter movement jump and single leg squat (right leg and left leg) were performed at the beginning of the intervention, and after the end of 6-week intervention program. According to the results significant interaction effect between group and time was found for the running speed and Squat Jump test. On the contrary, significant main effect were found were found for time on the running speed, Squat Jump, Counter movement jump and single leg squat. Conclusively, it has been reported that Whole body vibration is an effective method to improve Squat Jump performance in young non-competitive female artistic gymnasts.

Phosphorus nutritional knowledge among dialysis health care providers and patients: A multicenter observational study

BACKGROUND-AIMS

Phosphorus nutritional knowledge level of hemodialysis patients and renal nurses has been found to be low, while respective knowledge of nephrologists has not been studied yet. There are equivocal results regarding the association of phosphorus nutritional knowledge level and serum phosphorus values. The aim of this study was to assess phosphorus nutritional knowledge of hemodialysis patients, nephrologists and renal nurses and seek potential interventions to improve patients' adherence to phosphorus and overall nutritional guidelines.

METHODS

This cross-sectional observational study was conducted on sixty eight hemodialysis patients, 19 renal nurses and 11 nephrologists who were recruited from 3 hemodialysis units in Greece. Phosphorus nutritional knowledge of the participants was assessed by a 25-item item questionnaire (CKDKAT-N) which included 15 questions on phosphorus and 10 questions on protein, sodium, and potassium knowledge.

RESULTS

Nephrologists had higher CKDKAT-N total (19.1 ± 3.6 vs 14.1 ± 2.8 and 13.2 ± 2.8, P < 0.01) and phosphorus knowledge scores (10.6 ± 2.7 vs 7.6 ± 2.2 and 7.3 ± 2.0, P < 0.01) compared to renal nurses and patients respectively. There were no differences in total and phosphorus knowledge scores between nurses and patients. Patients and nurses answered correctly significantly less questions regarding phosphorus compared with the rest of the questions (P < 0.01) while no such difference was found in nephrologists. Serum phosphorus was positively correlated with phosphorus knowledge score (r = 0.31, P = 0.02), and negatively correlated with patient age (r = -0.34, P < 0.05). None of the patients, 11% of the nurses and 27% of the nephrologists answered correctly all three questions regarding P, K and Na dietary recommendations (P < 0.01).

CONCLUSIONS

The study confirms that hemodialysis patients have low renal nutrition knowledge while higher nutritional phosphorus knowledge does not lead to lower serum phosphorus values. Alarmingly, renal nurses have been found to have a similar level of knowledge with hemodialysis patients, something that needs to be taken into account when training the new dialysis staff. Nephrologists have superior knowledge; however they are still lacking essential nutritional knowledge that could affect patients' and nurses' overall understanding. Continuing education on nutrition of nephrologists and renal nurses could improve nutrition care of hemodialysis patients.

Hormonal responses following eccentric exercise in humans

OBJECTIVE

Mechanically overloaded muscle and its subsequent damage are strong stimuli for eliciting acute hormonal changes, while the muscle adaptation which occurs following exercise-induced muscle damage may involve complex hormonal responses before the completion of muscle regeneration. The purpose of this study was to investigate systemic responses of various hormones, as well as secreted proteins that are exercise-regulated and associated with muscle adaptation, for several days after eccentric exercise-induced muscle damage in humans.

DESIGN

Nine young male volunteers performed 50 maximal eccentric muscle actions using the knee extensor muscles of both legs. Blood samples were drawn before and at 6, 48 and 120 hours post exercise and serum levels of growth hormone (GH), insulin-like growth factor binding protein-3 (IGFBP-3), cortisol, prolactin, thyroid-stimulating hormone (TSH), free thyroxine (fT4), irisin, follistatin and sclerostin were measured. Myoglobin (Mb) concentration and lactate dehydrogenase (LDH) activity were also evaluated as indirect markers of muscle damage.

RESULTS

Significant alterations in Mb and LDH were observed over time after eccentric exercise (p=0.039-0.001). A late serum increase in fT4 and decrease in irisin levels, along with an early and persistent decrease in IGFBP-3 levels, were observed following the muscle-damaging exercise (p=0.049-0.016). GH, cortisol, prolactin, TSH, follistatin and sclerostin exhibited moderate changes during the recovery period after exercise, though without reaching statistical significance (p>0.05), while correlational analyses revealed significant associationsbetween GH and IGFBP-3, prolactin and sclerostin over time (p=0.049-0.001).

CONCLUSIONS

The significant hormonal responses observed in this study may indicate their involvement in the regenerative mechanisms following muscle damage, potentially as part of a regulatory network to support a normal adaptation process after muscle-damaging exercise.

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 3^rd-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 17β-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.