Heart rate and blood lactate responses during the volleyball match.

This study aimed to examine the heart rate and blood lactate responses of female volleyball players during the match according to the player positions. A total of 24 senior female volleyball players (middle blocker (n = 6), setter (n = 6), spiker (n = 6), and libero (n = 6)) were monitored for heart rate and blood lactate before, during and after a volleyball match. The mean heart rate and blood lactate level of volleyball players were determined 117.2 ± 13.9 bpm, 2.7 ± 1.2 mmol/L during the match. Heart rate was statistically different between all playing positions except middle blockers vs. spikers (p < 0.05). The blood lactate levels between the groups were not statistically different. The setters have the lowest heart rate and the libero players have the highest during the match. All subjects have a heart rate 50-60% and below 50% of their heart rate maximum during more than half of the match duration. These current results can be used by coaches to determine a specific training load based on the heart rate and blood lactate differences between playing positions.

Impact of Prolonged Absence of Organized Training on Body Composition, Neuromuscular Performance, and Aerobic Capacity: A Study in Youth Male Soccer Players Exposed to COVID-19 Lockdown.

The aim of this study is to examine how physical performance has changed after 15 weeks (109 days) long-term absence of organized training in youth soccer players imposed by the stay at home orders. A total of sixty-eight young male soccer players from different age categories (U15, U16, U17 and U19) voluntarily participated in the prospective cohort study. Body fat percentage (BF%), counter-movement jump (CMJ), 30 m sprint, change-of-direction (COD) and yo-yo intermittent recovery test level-1 (YYIRTL-1) were evaluated twice (before and after the detraining period). Subsequently, 2 × 2 repeated measures ANOVA was used to investigate group and time differences in repeated measurements. A significance level of p < 0.05 was implemented. CV and SWC values were calculated to test the reliability of the tests performed at different times. Statistical analysis was performed using the IBM SPSS statistics software (v.25, IBM, New York, NY, USA). Significant increments in BF%, 30 m sprint, and COD (left and right), and also significant decrements in CMJ and YYIRTL-1, were found after the detraining period. A long-term detraining period due to the stay at home orders has a detrimental effect on body composition, neuromuscular performances, and aerobic capacity in youth soccer players.

The Effect of Cold Water Immersion on Cardiac Troponin T and Myoglobin Levels.

OBJECTIVES: Skeletal and cardiac damages occurring in the high intensity training, can reduce the efficiency of the athlete in the next training session. Cold water immersion can help for more efficient recovery in athletes. This study was conducted to investigate the effect of cold water immersion applied after exercise on cardiac troponin T and myoglobin levels. MATERIAL AND METHODS: The experimental group comprised of a total of 23 male football players, of which 12 comprised the study group (age 22.4±3.16 years, height 176.9±6.08 cm, BMI 22.61±1.27 kg/m2) and 11 comprised the control group (age 21.3±2.21 years, height 175.8±5.52 cm, BMI 21.24±3.15 kg/m2).The athletes provided blood samples before exercise (BE) for troponin T (cTnT) and myoglobin (Mb) measurement. Consequently, muscle damage exercise protocol consisting of depth jump, and immediately after this, cold-water immersion at 15°C was applied to experimental group for 10 minutes. The athletes provided blood samples after 2 (2h) and 24 (24h) hours from cold water immersion. Athletes in the control group underwent the same measurements except application of cold-water immersion. RESULTS: While there was a significant difference (p<0.05) between the experimental and the control groups regarding troponin values, no significant difference was found for the myoglobin values (p>0.05). CONCLUSIONS: In this study, cTnT level, which is regarded as one of the most specific markers of cardiac injury, was found to be lower in the athletes who underwent cold water immersion. These results indicate that the recovery time may be shorter in athletes undergoing cold-water immersion.

Physiological responses and match characteristics in professional tennis players during a one-hour simulated tennis match.

The purpose of this study was to investigate the effects of serve and return game situations on physiological responses and match characteristics in professional male tennis players during one hour-long simulated singles tennis matches. Ten internationally ranked tennis players (age 22.2 ± 2.8 years; body height 180.7 ± 4.4 cm; body mass 75.9 ± 8.9 kg) participated in this study. Their physiological responses were measured using two portable analyzers during indoor hard court matches. Ratings of perceived exertion were also determined at the end of the game. The variables describing the characteristics of the matches determined from video recordings were: (a) duration of rallies; (b) rest time; (c) work-to-rest ratio; (d) effective playing time; and (d) strokes per rally. Significant differences (p<0.05) were found between serving and returning conditions in an hour-long simulated singles tennis match in terms of oxygen uptake, a heart rate, ratings of perceived exertion, pulmonary ventilation, respiration frequency and a respiratory gas exchange ratio. In addition, both the heart rate and ratings of perceived exertion responses were moderately correlated with the duration of rallies and strokes per rally (r = 0.60 to 0.26; p<0.05). Taken together, these results indicate that the serve game situation has a significant effect on the physiological response in an hour-long simulated tennis match between professional male tennis players. These findings might be used for the physiological adaptations required for tennis-specific aerobic endurance.

Effects of acute L-carnitine intake on metabolic and blood lactate levels of elite badminton players.

OBJECTIVES: Purpose of this study is to research the effects of acute L-Carnitine intake on badminton players' metabolic and blood lactate values. DESIGN: A total of 16 Turkish national badminton players (8 male, 8 female) were voluntarily participated into study. MaxVO2, MET, energy consumption, HR (heart rate), VE (minute ventilation), R (respiratory exchange ratio), AT (anaerobic threshold), oxygen pulse and blood lactate (LA) of subjects were measured by Sensormedics VmaxST and Accutrend Lactate Analyzer. The participants were subjected to the test protocol twice before and after 2g of L-Carnitine intake. The data were evaluated by the use of SPSS 13.0 for Windows. RESULTS: No significant differences were found between 1st. (without L-Carnitine intake) and 2nd. (with L-Carnitine intake) measurements of female participants as regards to all measured parameters. There was a significant difference in EMHR (exercise maximum heart rate) of males between two measurements (p<0.05). However the differences in other parameters were not significant. AT values of female subjects were not significant difference (p>0.05). Respiratory exchange ratio of males was significantly different at anaerobic threshold (p<0.05). CONCLUSION: Results of this study show that L-carnitine intake one hour prior to the exercise has no effect on the metabolic and blood lactate values of badminton players.

Effect of acute maximal aerobic exercise upon the trace element levels in blood.

This study was carried out in order to determine the effect of acute maximal aerobic exercise on the copper and zinc levels in blood. The study was participated by 16 healthy male university students with an average age of 19.44+/-1.63. There were 5 cc blood samples taken from the participants before and after they had been subjected to aerobic loading process (20 m shuttle run). The copper and zinc levels in the blood samples were determined by the use of Anodic Stripping Voltammetry (ASV) technique. The data obtained were evaluated by simple t test and SPSS software. The results revealed the fact that the blood Zn levels of the participants increased and Cu levels decreased with statistical significant extent (p<0.01) after maximal aerobic loading. There found no correlation between the maximal aerobic power levels (Max VO2) of the participants and their resting copper and zinc blood levels. However blood zinc and Max VO2 levels of the participants were positively correlated after maximal aerobic loading. The participants were fed on a zinc and copper free diet six week prior to the program. They were also asked not to use copper and zinc containing vitamins during this period.

The change of blood Pb levels of basketball players after strenuous exercise.

This study is related to the investigation of the Pb levels in blood of the 12 healthy University male basketball players before and after a strenuous training session by the use of square wave anodic stripping voltammetry. Although the results do not show acute lead intoxication it is obvious that blood lead levels show significant increase after training sessions. The average increase in blood lead levels is 297%. This increase is largely due to increased respiration rate during the training period.

Effect of six weeks aerobic training upon blood trace metals levels.

This study was carried out to investigate the effects of 6-week aerobic exercise program upon blood Zn and Cu levels. There were 12 male university students with an average age of 21.67+/-0.89 years and no regular training habits participated in the study. The participants were subjected three days a week 1 hour a day continuous running program on treadmill with an intensity of 60-70% for a period of six weeks. They were fed with zinc and copper free diet throughout the study and it was made sure that they were not using copper or zinc containing vitamin tablets. The difference between the pre and post study period were found to be statistically significant as regards to both resting and maximal loading conditions (p<0.01). The pre and post training maxVO2 values were also found to be positively correlated with the copper and zinc levels in blood. Both the copper and zinc blood levels were found decreased after the training period p<0.05.