Effects of Ramadan intermittent fasting on performance, physiological responses, and bioenergetic pathway contributions during repeated sprint exercise.

Introduction: This investigation aims to elucidate the impact of Ramadan intermittent fasting on performance, physiological responses, and bioenergetic pathway contributions during repeated sprints. Methods: Fourteen active male Muslim athletes (age = 22.4 ± 1.8 years, body weight = 69.5 ± 3.8 kg, height = 176 ± 5.1 cm) executed a repeated sprint protocol, consisting of ten 20-meter sprints with 15-s passive recovery intervals, during both fasting and non-fasting conditions. The fasting session was conducted after a 12-14 h fast following Sahur (the pre-dawn meal during Ramadan). In contrast, the non-fasting session occurred before the Ramadan fasting period began, during the same hours of the day, at a time when fasting was not yet required for the athletes. Bioenergetic pathway contributions during repeated sprints were quantified using the PCr-LA-O2 method. Results: The mean sprint time during fasting sessions was 3.4 ± 0.3 s compared to 3.3 ± 0.2 s in non-fasting sessions, indicating a trend approaching the threshold of significance for slower times in the fasted state (p = 0.052, effect size (ES) = 0.34). In terms of bioenergetic contributions, the total metabolic energy expenditure (TEE) was slightly lower during fasting sessions (236.5 ± 22 kJ) compared to non-fasting sessions (245.2 ± 21.7 kJ), but this difference was not statistically significant (p = 0.102, ES = 0.40). Similarly, metabolic energy expenditure per sprint was 23.7 ± 2.2 kJ in fasting conditions compared to 24.5 ± 2.2 kJ in non-fasting conditions (p = 0.106, ES = 0.35). The oxidative energy contribution did not differ significantly between fasting (34.2 ± 4.1 kJ) and non-fasting conditions (34.2 ± 4.1 vs. 35.5 ± 5.2 kJ; p = 0.238, ES = 0.28). Similarly, lactic (60.4 ± 7.6 vs. 59.2 ± 8.3 kJ; p = 0.484, ES = 0.15); and alactic (149.3 ± 19.9 vs. 143 ± 21.5 kJ; p = 0.137, ES = 0.30) energy contributions showed no significant differences between the fasting and non-fasting sessions. The percentage of performance decrement (Pdec) and the percentage contributions of oxidative, lactic, and alactic pathways to the total energy expenditure did not differ significantly between the fasting and non-fasting conditions, indicating a similar bioenergetic profile across both conditions. Conclusion: The present findings indicate no significant differences in performance metrics and metabolic outcomes between fasted and non-fasted states. Future assessments with longer duration and higher intensity protocols may provide further insights.

Effects of exercise on serum ischemia-modified albumin, brain natriuretic peptide and copeptin levels in boxers and kick boxers.

Introduction: boxing and kick boxing are combat sports that can cause severe head, neck, face and hand injuries during fighting. Then, traumatic brain injury (TBI) incidence is high in these sports. Ischemia-modified albumin (IMA), brain natriuretic peptide (BNP) and copeptin have diagnostic and prognostic value for cardiac and non-cardiac ischemic events. The purpose of this study is to evaluate exercise-induced variations of serum IMA, BNP and copeptin. Methods: twenty male boxers, twenty-three male kick boxers and twenty-three age-matched male were enrolled in the study. Health assessment data were analysed. Boxers and kick boxers underwent an exercise program including training plus fighting matches. Serum samples were collected in the pre- and post-exercise periods. Serum IMA, BNP and copeptin concentrations were measured in these specimens using ELISA reagents. Results: comparative analysis of analytes before and after exercise showed that exercise significantly increased serum IMA, BNP and copeptin levels both in boxers and kick boxers. Conclusion: in conclusion, IMA, BNP and copeptin levels may be candidate biomarkers for exercise-related traumatic brain injuries. The identification of new biomarkers in patients with acute and chronic neurological disorders is of considerable interest to clinicians. Then, further studies should be conducted to evaluate the possible role of IMA, BNP and copeptin in TBI pathophysiology.

The Effect of Citrulline/Malate on Blood Lactate Levels in Intensive Exercise.

The purpose of this study was to examine the effects of Citrulline/Malate supplementation with intensive training on blood lactate level in active handball players. The athletes were subjected to intense training for 4 weeks, 4 days a week, mainly pre-season strength and technique training. In this training period, stimol group (n = 11) athletes were given stimol 3 times a day as 1 g for breakfast, 1 g for lunch, and 1 g for dinner while the placebo group (n = 11) athletes were given only placebo in the same dosage and the same color at the same time. Blood lactate levels in athletes were measured 4 times, prior to and after a 1-month program as follows: rest (R), end effort (EE), recuperation 5 min (R5 m), and recuperation 20 min (R20 m). Blood lactate levels were compared both as intra-group and between the groups. In intra-group comparison, no change was observed in blood lactate levels in placebo group while a significant difference was found in the levels of stimol group as p < 0.05 with a 49.8% decrease in blood lactate level. In the measurements between groups, in the post-test measurements made after the training period, significant differences as p < 0.05 were found with a 60.7% decrease in blood lactate level EE. Considerable decline was seen especially immediately after exercise in blood lactate levels of the athletes being given stimol supplement. In this case, we can say that Citrulline/Malate supplementation may contribute positively to the performance of athletes and may help postpone fatigue at excessive or prolonged activity.

Tc-99m MDP bone scintigraphy in the evaluation of the joint damage in asymptomatic alpine ski racers.

AIM: To evaluate the role of 99m-technetium methylene diphosphonate (Tc-99m MDP) bone scintigraphy on the detection of joint damage in asymptomatic alpine ski racers. MATERIALS AND METHODS: This study included 20 male asymptomatic alpine ski racers (age range: 18-21 years). None of the skiers had a history of ski crashes. Bone scan findings of the racers were examined with Tc-99m MDP bone scintigraphy during the active racing season and the inactive training season. Planar anterior and posterior images of hip, knee, and ankle joints were obtained 4 h after intravenous injection of 20 mCi Tc-99m MDP. All images were interpreted visually by 2 experienced nuclear medicine physicians. Free regions of interest were drawn on hip, knee, and ankle joints, as well as background regions. Joint-to-background ratios were calculated for each joint, and the uptake ratios of both right and left joints during active ski season were compared to those during the inactive training period. RESULTS: Uptake ratios of the right and left hip, knee, and ankle joints were significantly higher during the active racing period than those calculated during the inactive period (P < 0.005). CONCLUSION: Bone scintigraphy may have an important role in detecting joint injuries of hip, knee, and ankle joints in asymptomatic alpine ski racers and can be used successfully when MRI is unavailable.