Nevin Atalay Güzel

The effects of vitamin C supplementation on oxidative stress and antioxidant content in the brains of chronically exercised rats.

The purpose of this study was to ascertain whether vitamin C supplementation during chronic exercise training alters rat brain antioxidant content. Female Wistar albino rats were exercised on a treadmill for 30 min/day for 6.5 weeks and were administered daily intraperitoneal injections of vitamin C (20 mg/kg). After the training period, chronically exercised rats showed no significant changes in total brain thiobarbituric acid reactive substances (TBARS) levels. In contrast, rats supplemented with vitamin C during the training period showed significantly elevated brain TBARS levels. If such results were extrapolated to man, where vitamin supplementation is a common practice, this would indicate that vitamin C supplementation may not protect brain tissue against exercise-induced oxidative damage, in such circumstances, this water-soluble antioxidant behaves as a pro-oxidant. (Mol Cell Biochem xxx: 135–138, 2005)

The effects of acute L-carnitine supplementation on endurance performance of athletes.

Abstract Orer, GE and Guzel, NA. The effects of acute L-carnitine supplementation on endurance performance of athletes. J Strength Cond Res 28(2): 514–519, 2014—This study examined the effect of acute L-carnitine loading on the endurance performance of footballers. Measurements were performed on 26 candidate professional footballers who volunteered to take part in the study. Athletes were given a glass of fruit juice 1 hour before applying L-carnitine with the double-blind method. Then, 12 participants were given 3 g of L-carnitine (LK-3) and the remaining 14 were given 4 g (LK-4). Athletes began the exercise test at a running speed of 8 km·h−1 and then continued at 10 km·h−1. The speed was increased 1 km·h−1 every 3 minutes, and the test continued until the subject chose to quit. Heart rate was registered using a portable telemetric heart rate monitor during the test. Blood samples were taken from the earlobes of the footballers both before the test and before the speed increase (during the 1-minute interval), and the lactate (La) concentration was measured electroenzymatically. The test was repeated after 1 week as a group of placebos (P-3 and P-4). The result showed that the running speeds corresponding to specific La concentrations were increased, and La and heart rate responses to the running speeds were decreased in both supplemented groups compared with placebos (p ⩽ 0.05). A significant reduction in heart rate was found in LK-4 and P-4 (p ⩽ 0.05). When the Borg responses to the running speeds were analyzed, a significant difference was found in both supplemented groups (p ⩽ 0.05). The results show that 3 or 4 g of L-carnitine taken before physical exercise prolonged exhaustion.

Differences in strength, flexibility and stability in freestyle and Greco-Roman wrestlers

BACKGROUND AND OBJECTIVES Wrestling includes a variety of functional properties: muscular strength, flexibility, neuromuscular coordination, and static and dynamic balance. The aim of the study was to identify differences in the strength, flexibility, postural stability and core stabilization of young national and international wrestlers in different weight groups. MATERIAL AND METHOD Eighty-one male wrestlers (17-21 years old) were divided into 6 groups according to their body mass (light, middle and heavy) and wrestling style. The lumbosacral flexion, extension and lateral flexion range of motion, hamstring extensibility, back and leg muscle strength, postural stability, and core stabilization were assessed. RESULTS Greco-Roman wrestlers had a higher lean body mass (6-12%) compared with freestyle wrestlers. However, the trunk lateral flexion flexibility was better in the Greco-Roman wrestlers (6-7%) than in the freestyle wrestlers, and the absolute back strength (BS) and leg strength (LS) were similar for both styles of wrestling. The BS/LBM and LS/LBM in the freestyle wrestlers were greater than in the Greco-Roman wrestlers, and the Light weight Greco-Roman wrestlers had the highest BS/LBM. The heavy weight Greco-Roman wrestlers and the light weight freestyle wrestlers had the greatest LS/LBM values. The postural control was similar for the two styles of wrestlers; however, the heavy weight Greco-Roman wrestlers had greater postural control in all directions compared with the light and middle weight Greco-Roman wrestlers. The core stabilization did not differ for the Greco-Roman and freestyle wrestlers except in the lateral bridge. CONCLUSION The style of wrestling demonstrates different strength, flexibility and stability demands on the body. The differences between Greco-Roman and freestyle wrestlers may be due to the wrestling style differences in training and to competition-related demands. LEVEL OF EVIDENCE Comparative study, level lV (case series).

Relationship Between Body Composition and Lung Function in Elderly Men and Women

IntroductionThe purpose of this study was to evaluate the relationship between body composition parameters and lung functions including vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1:VC ratio, and FEV1:FVC ratio in elderly men and women.MethodsThe study was a cross-sectional evaluation of 99 healthy men and women (aged 60–88 years). Anthropometric and body composition parameters (including fat mass [FM], fat-free mass [FFM] and percentage body fat [%BF]) were evaluated using the skinfold method, and lung function was examined using spirometry.ResultsData analysis showed %BF, body FM and body mass index (BMI) of women to be significantly higher than men. Also, their body FFM was significantly less than men (P<0.05). Lung volume (P<0.01) and lung capacity values (P<0.05) (VC, FVC, FEV1, FEV1:VC, FEV1:FVC) of women were significantly less than men. There was a positive significant relationship between the FFM versus FVC and FEV1 values of women and men. A negative significant relationship was demonstrated between body FM, BMI and FVC of all subjects.ConclusionThis investigation showed that women aged between 60 and 88 years had a lower lung capacity compared to men of the same age. Older women were found to have a higher body fat ratio than men, and it was found that increasing %BF and BMI had a negative effect on lung functions in both sexes.

Does Lymphedema Affect the Postural Stability in Women After Breast Cancer

Aim: The aim of this study was to evaluate the static postural stability and fall risk of preelderly women with unilateral secondary lymphedema after breast cancer. Methods: This study was conducted on 46 preelderly women (24 with unilateral secondary lymphedema and 22 healthy) aged from 52 to 69 years. The Biodex Balance System was used to measure the parameters of postural stability and fall risk. The data acquisition involved 3 trials of 20 seconds to test the postural stability test. It was made in 3 directions (overall, anterior-posterior [AP], and mediolateral [ML]) and 2 conditions (once with open eyes, once with eyes closed). The fall-risk test was performed under the following conditions: (1) eyes open, firm surface; (2) eyes closed, firm surface; (3) eyes open, foam surface; and (4) eyes closed, foam surface. Results: For the postural stability, significant differences (P ⩽ .000) were observed in overall, AP, and ML displacement parameters in eyes closed condition between the lymphedema and healthy groups. There were no statistically significant differences in the fall-risk test results among the lymphedema and healthy group (P > 0.05). Conclusion: Preelderly women with unilateral lymphedema exhibited a lower postural stability compared with health women. These results lead to think us that asymmetric fluid distribution in the upper body parts increases postural sway and leaving them more vulnerable to falls.

The effect of 1-month thyme using in elite sportsmen on oxidant stress and anti-oxidant capacity

The object of the study is to determine the effect of thyme loading during exercise at elite wrestlers on oxidant stress and anti-oxidant capacity. Totally 18 elite wrestlers were involved in the study. The wrestlers were randomly divided into two groups, experimental and placebo. The subjects were loaded 1 g dried thyme tea three times a day after meals during 35-day period. The blood samples were taken before and after loading thyme, and total antioxidant capacity (TAC), melondialdehyde (MDA) and total sulphydryl group (RSH) were analysed. To evaluate the dates, Wilcoxon signed rank test was used for in-group evaluation and Mann–Whitney U test was used for inter group evaluation and significance level α was set at 0.05. While there were no differences between groups before loading thyme, TAC values were found meaningfully increased after loading in experimental group (p<0.05). However, the decrease in MDA values of the experimental group after loading thyme was statistically significant (p<0.01). The decreases in RSH values of the experimental group were insignificant (p>0.05). In the other hand experimental group decreasing of the MDA values and increasing of the TAC values were found statically significant compared with placebo groups (p<0.05). But compared with two groups RSH values were statically insignificant. It was concluded that thyme loading increases enzymatic antioxidant capacity but does not have any effects on non-enzymatic antioxidant structures during exercise. However, thyme loading reduced oxidant stress in elite sportsmen.

The Relationship Between Endurance Of Periscapular Muscles, Anaerobic Performance And Agility In Professional Athletes

Objective: The purpose of this study was to identify relationships between endurance of periscapular muscle, anaerobic performance and agility in professional athletes. Methods: 70 professional basketball, volleyball, and handball players (male: 25 female: 45 age 20.41±5.72, BMI: 21.70±2.51) were included to this study. Anaerobic performance was assessed with vertical jump test. Periscapular muscles endurance was evaluated using scapular muscle endurance test and agility was measured hexagonal obstacle test. Statistical analysis was performed using the statistical software SPSS 22. Results: Spearman correlation analysis results showed that there was positive significant correlation between anaerobic performance and endurance of periscapular muscles (p<0.05 r=0.341). A negative significant relationship was demonstrated between anaerobic performance and agility (p<0.05 r=-0.332), and between agility and endurance of periscapular muscles (p<0.05 r=-0.334). Discussion: The scapula acts as an axis, transmitting the power and high energy of the lower extremities and trunk to the upper extremities. The muscles surrounding the scapula provide proximal stability for the upper extremity and act as a fix while the distal part is moving. When weakness of scapular musculature has occurred, normal scapular positioning and mechanics may be altered. Therefore, scapular stabilization failure may lead to poor anaerobic performance. These results indicate that periscapular muscle endurance affects anaerobic and agility performance in sports.

The relationship between pectoralis minor length, scapular muscle endurance and core endurance in athletes

Objective: The purpose of this study was to identify relationships between core endurance, scapular muscle endurance and pectoralis minor length in athletes. Methods: 69 professional athletes in different branches (44 men, 25 women, mean age 20.41±5.72, height 176.0±0.1, and weight 68.2±12.8) were included to this study. Pectoralis minor length was measured in supine. In this position linear distance from treatment table to posterior aspect of the acromion was measured. Core endurance was evaluated using Mcgill Core Endurance Tests. Scapular muscle endurance was assessed with scapular endurance test. Statistical analysis was performed using the statistical software SPSS. Results: Spearman correlation analysis results showed that there was correlation between pectoralis minor length and scapular muscle endurance (r=0.281, p<0.05). A positive correlation was found between pectoralis minor length and core endurance (r= 0.517, p<0.05). There was correlation between scapular muscle endurance and core endurance (r=0.524, p<0.05). Conclusions: In this study, it was shown that there were statistically significant relationship between pectoralis minor length, scapular muscle endurance and core endurance. Pectoralis minor length affects scapula biomechanics. Change in scapula biomechanics may cause reduction in scapular muscle endurance. It may affect core endurance via kinetic chain. Therefore, it can be suggested pectoralis minor stretching should be integrated to normal sports specific training programmes in professional athletes.

The Validity and Reliability of Knee Proprioception Measurement Performed With Inclinometer in Different Positions

CONTEXT Proprioception is the basic element of the spontaneous control of movement, balance and joint stability. Therefore, it is necessary for the execution of walking and daily and sport activities. Loss of proprioception of the knee, which may cause a new injury, is important to evaluate the position sense of the joint during the rehabilitation period. However, the evaluation methods that are used are very expensive, complicated and non-portable, or the measuring method is difficult to implement. OBJECTIVE We demonstrated the validity and reliability of knee proprioception measurements performed in the open kinetic chain position and closed kinetic chain position with a dual inclinometer. DESIGN We assessed the validity and intra-tester reliability of a digital inclinometer for measuring the knee joint position sense in different positions. SETTING Clinical laboratory. PARTICIPANTS We enrolled 22 participants (age = 21.8 ± 0.95 years, height = 172 ± 9.1 cm, weight = 64.9 ± 14 kg) into the study. INTERVENTION The same investigator used an inclinometer to take knee proprioception measurements in open and closed kinetic chain positions. MAIN OUTCOME MEASURES The relative angular error was calculated by taking the arithmetic average of the difference between the target angle and reproduced angle and was the main outcome measure. RESULTS We found that the dynamometer-inclinometer had a moderate ICC value (ICC = 0.594, SEM = 1.60, p = 0.005), whereas inclinometer t1 vs inclinometer t2 (ICC = 0.778, SEM = 0.62, p < 0.001) and closed kinetic chain position t1 and closed kinetic chain position t2 (ICC = 0.888, SEM = 0.63, p < 0.001) had high ICC values. CONCLUSION Knee proprioception measurements performed with a dual inclinometer were reliable in the closed kinetic chain position in healthy, sedentary individuals and were valid and reliable in the open kinetic chain position.

Recovery levels after eccentric and concentric loading in maximal force

[Purpose] The aim of this study was to compare the differences in recovery periods after maximal concentric and eccentric exercises. [Subjects and Methods] Twenty-two participants voluntarily participated and were divided into two groups: the athlete and sedentary groups. An incremental treadmill running test was performed until exhaustion. During the subsequent passive recovery session, heart rate and venous blood lactate level were determined every 3 minutes until the venous blood lactate level reached 2 mmol/l. The same test protocol was implemented 15 days later. [Results] Both groups showed significantly shorter running durations in concentric exercise, while significant differences were found between the athlete and sedentary groups in terms of venous blood lactate level responses. In addition, there were significant differences between the athlete and sedentary groups in terms of running duration and heart rate in concentric and eccentric exercises. [Conclusion] The present study revealed no difference between the athlete and sedentary groups in terms of recovery durations after eccentric and concentric loadings, although the athletes demonstrated faster recovery in terms of HR compared with the sedentary group. It was thought that concentric exercises cause greater physiological responses.