The effect of static stretching on lactate removal during recovery from high intensity exercise

The purpose of this study was to compare the effectiveness of static stretching on lactate removal following high intensity exercise to a passive and a low intensity cycling recovery. Eight male subjects, ages 19-50, with an average VO2{dollar}\sb\max{dollar} of 46.1 {dollar}\pm{dollar} 8.2 ml/kg.min., performed a high intensity cycling protocol followed by one of the three possible recovery periods: sitting, stretching, or cycling. To determine blood lactate concentration, a fingertip blood sample was taken at minute 0, 3, 8, 16, 24, and 32 of the recovery periods. Blood lactate was significantly lower in the cycling and stretching recoveries versus the sitting recovery. Compared to the sitting recovery, lactate half-time was 44% faster in the cycling recovery and 24% faster in the stretching recovery. These results indicate that stretching provides moderate benefits in the reduction of lactate following exercise

Natural Killer cells responsiveness to physical esercise: a brief review

Natural killer cells (NK) are a group of peripheral blood lymphocytes which display cytotoxic ac- tivity against a wide range of tumour cells. They are a consistent part of the inflammatory re- sponse that is activated when either internal or external injuries occur as they are able to syn- thesize perforins. An important role is played by NK cells in the host defence against tumours without expressing any antigen-binding recap- tor in their membrane which, however, distin- guish T and B lymphocytes. NK activity appears early in the immune response, thus providing immediate protection during the time required for the activation and proliferation of cytotoxic T lymphocytes and for their differentiation into functional cells. Even though much research regarding the effects of aerobic training exercise on NK cell numbers and function, there appears to be much controversy regarding its effect. NK cells are rapidly mobilized into circulation in response to acute exercise, most likely by in- creased shear stress and catecholamine-in- duced down-regulation of adhesion molecule expression. However, tissue injury and inflam- mation which often accompanies strenuous ex- ercise have been associated to post-exercise NK cell suppression. Scientific evidence indicates exercise-induced changes in NK cell redistribu- tion and function should be strongly influenced by stress hormones including catecholamines, cortisol and prolactin as well as by soluble me- diators such as cytokines and prostaglandins. The role of exercise therapy in cancer patients and survivors rehabilitation is becoming increasingly important as it is thought to modulate immunity and inflammation. However, more knowledge about the effects of exercise on im-mune function in these patients is needed

High-intensity cycling training:the effect of work-to-rest intervals on running performance measures

The work-to-rest ratio during cycling-based high-intensity interval training (HIT) could be important in regulating physiological and performance adaptations. We sought to determine the effectiveness of cycling-based HIT with different work-to-rest ratios for long-distance running. Thirty-two long-distance runners (age: 39 ± 8 years; sex: 14 men, 18 women; average weekly running training volume: 25 miles) underwent baseline testing (3-km time-trial, V[Combining Dot Above]O2peak and time to exhaustion, and Wingate test) before a 2-week matched-work cycling HIT of 6 × 10-second sprints with different rest periods (30 seconds [R30], 80 seconds [R80], 120 seconds [R120], or control). Three-kilometer time trial was significantly improved in the R30 group only (3.1 ± 4.0%, p = 0.04), whereas time to exhaustion was significantly increased in the 2 groups with a lower work-to-rest ratio (R30 group 6.4 ± 6.3%, p = 0.003 vs. R80 group 4.4 ± 2.7%, p = 0.03 vs. R120 group 1.9 ± 5.0%, p = 0.2). However, improvements in average power production were significantly greater with a higher work-to-rest ratio (R30 group 0.3 ± 4.1%, p = 0.8 vs. R80 group 4.6 ± 4.2%, p = 0.03 vs. R120 group 5.3 ± 5.9%, p = 0.02), whereas peak power significantly increased only in the R80 group (8.5 ± 8.2%, p = 0.04) but not in the R30 group (4.3 ± 6.1%, p = 0.3) or in the R120 group (7.1 ± 7.9%, p = 0.09). Therefore, cycling-based HIT is an effective way to improve running performance, and the type and magnitude of adaptation is dependent on the work-to-rest ratio

Acute Effect of Quadriceps Myofascial Tissue Rolling Using A Mechanical Self-Myofascial Release Roller-Massager on Performance and Recovery in Young Elite Speed Skaters

Objectives: The main purpose of the present study was to investigate the acute effects of myofascial tissue rolling on endurance performance and recovery using a novel designed mechanical self-induced multi-bar roller-massager. Methods: a randomized crossover, repeated measure design was used. Eight national levelled, junior and neo-senior, speed skaters underwent a 10 min myofascial quadriceps rolling pre- and fifteen minutes post- a stepwise incremental cycling-test to exhaustion followed by a Wingate performance-test. The myofascial quadriceps rolling was used in one out of two laboratory testing-days. Time to exhaustion, peak oxygen uptake (VO2peak), blood lactate concentration during 30 min of recovery, and peak- and mean- power during the consecutive Wingate test were recorded. Results: Myofascial quadriceps rolling using roller-massager resulted in higher blood lactate concentration at exhaustion and a larger blood lactate clearance after 10 min to post exhaustion test (both p < 0.05), a tendency for a positive effect on Wingate peak-power (p = 0.084; d = 0.71), whereas no marked differences were observed on VO2peak, time to exhaustion and Wingate mean-power. Conclusion: Despite indications for potential benefits of the quadriceps myofascial tissue release using the mechanical self-induced multi-bar roller-massager on blood lactate concentration and Wingate peak-power, the myofascial tissue release gave no marked performance improvements nor indications of negative effects. Future studies could examine the long-term effects of myofascial tissue release on performance and recovery. Furthermore, integrating a measure of the participants’ subjective experience pre- and post the myofascial tissue release would be of great interest.publishedVersio

Investigating the physiological mechanisms of the oxygen consumption \u201cslow component\u201d.

The study of the oxygen consumption (VO2) kinetics is focused on the understanding of how human metabolism adjusts during the transition from a condition of resting/movement to another in order to satisfy the new energetic demand. As an integrated index of pulmonary, cardiovascular and muscles capacity VO2 kinetics have gained progressively increasing interests during the XX and the early XXI centuries. Thanks to the development of new technologies as well as an always increasing community of interested scientists in this subject, the knowledge in this field has been expanded considerably. However, some of the topics related to VO2 kinetics remain debated and call for further research. One of these topics is the loss of efficiency of human locomotion that occurs at the higher metabolic intensities, after the transitory period in which a new steady-state in VO2 should be achieved. This phenomenon is typically called VO2 \u201cslow component\u201d, as representative of a further increase in VO2 after the expected steady-state. The importance of the VO2 slow component lies in its link with exercise tolerance and on the understanding of the adaptations of the human body during physical activity. Therefore, researchers have tried to define the physiological underpinning of the slow component and to develop intervention strategies to reduce its amplitude. Nevertheless, a number of physiological uncertainties regarding the mechanistic bases of the slow component exist and require to be clarified. The purpose of this thesis was to deal with this gap and to study the origins of the VO2 slow component, and the loss of efficiency of locomotion that the slow component represents. In chapter one, a brief explanation of the VO2 response during exercise and the current explanatory theories for the VO2 slow component are provided. In chapter two, the experimental aims of the thesis are explained. Then, the results of four different studies are presented in chapters three, four, five, and six. Finally, chapter seven summarizes the main findings of this research work

Determination of the Effectiveness of the ZetrOZ Wearable Ultrasound Device (SAM) for the Post-exercise Clearance of Lactic Acid

Athletes performing in multiple round competitions seek rapid recovery from exercise and restoration of optimal muscle function. The increase in blood lactic acid concentration while performing intense exercise has been well documented; however interventions have not demonstrated the ability to significantly improve lactate removal beyond that of passive recovery. Low intensity therapeutic ultrasound has been previously shown to increase blood flow, fluid circulation, vasodilation, and cellular metabolism. PURPOSE: To determine if wearing a long-duration ultrasound therapy device on muscles can accelerate lactic acid kinetics to promote clearance from blood. METHODS: A randomized, double blind cross-over study utilizing a lactate-inducing circuit weight training protocol was performed by 10 male participants (22.1 ± 0.46 years). During the first visit to the lab, the 1-repetition maximum (1-RM) for each participant was estimated for the following exercises 1) lunge, 2) squat, 3) leg press, 4) leg extension, and 5) leg curl. During the next two visits participants performed two circuits of the five aforementioned lower body exercises at 70% of their 1-RM. The exercises were performed while wearing functional ultrasound devices during one visit and placebo devices during the other visit. The ultrasound devices were attached to both the quadricep and hamstring muscle groups and worn for 1 hour. Blood lactic acid was measured in duplicate at baseline as well as at 0, 2, 5, 10, 20, 40, and 60 min post-exercise. The area under the curve (AUC) of lactic acid concentration versus post-exercise time was calculated. RESULTS: AUC resulting from functional ultrasound devices (344.31 ± 41.12) was significantly lower than placebo devices (396.09 ± 35.24). Lactic acid values from functional devices at time 0, 2, 5, 20, and 40 min post-exercise (10.83 ± 0.8, 10.61 ± 0.83, 10.15 ± 0.96 , 6.97 ± 1.04, 3.60 ± 0.55 mmol/L) were significantly lower than placebo respectively (12.71 ± 1.07, 11.86 ± 0.61, 11.69 ± 0.62, 7.94 ± .909, 4.48 ± .55 mmol/L). There were no significant differences at time-points 10 and 60 min post-exercise. CONCLUSION: These results suggest that a wearable therapeutic ultrasound device promotes blood lactic acid clearance immediately following high intensity exercise, but may offer reduced benefit later in the recovery process

Short-Term Effects of Glutamine Supplementation on Levels of Blood Lactate and Fatigue Index in Male Elite Swimmers

Food supplementations are public assistance for a variety of championships sports. Competitive and recreational athletes use the nutritional supplements to improve their performance in a long time. In this context, there is lack of information about whether glutamine supplementation has the potential to help improve the muscle recovery after a period of intense aerobic exercise to exhaustion. This study aimed to assess short-term effect of glutamine supplementation on the levels of lactate and fatigue index in male elite swimmers.  Research method was mid-experimental and research design was a pretest-posttest with control group that was administered as double-blind. Twenty swimmers with age range of 26-18 years were selected based on convenient sampling. Then, based on swimming record results of 50 and 100 m freestyle breasts  were randomly divided into glutamine and swimming training group (n = 10) or placebo and exercise swimming group (n=10 ). Then the glutamine was given to supplementation group and the placebo was given to the control group, both groups began to swim for 4 weeks. Studied variables including lactate levels, fatigue and athletic performance index were measured before and after the study.  The results showed that use of glutamine amino acids led to a significant reduction in the fatigue index and produced lactate in the supplementation group compared to the placebo group. The time of athletes' performance wasn’t significantly increased.  The results showed the glutamine supplementation in areas such as swimming where the athlete must take part in a day in several competition, has a significant impact on the reduction of blood lactate concentration and more endurance of athletes than accumulation of lactic acid and reduction of swimming athletes fatigue index . However, more research is needed in this area

Short-Term Effects of Glutamine Supplementation on Levels of Blood Lactate and Fatigue Index in Male Elite Swimmers

Food supplementations are public assistance for a variety of championships sports. Competitive and recreational athletes use the nutritional supplements to improve their performance in a long time. In this context, there is lack of information about whether glutamine supplementation has the potential to help improve the muscle recovery after a period of intense aerobic exercise to exhaustion. This study aimed to assess short-term effect of glutamine supplementation on the levels of lactate and fatigue index in male elite swimmers.  Research method was mid-experimental and research design was a pretest-posttest with control group that was administered as double-blind. Twenty swimmers with age range of 26-18 years were selected based on convenient sampling. Then, based on swimming record results of 50 and 100 m freestyle breasts  were randomly divided into glutamine and swimming training group (n = 10) or placebo and exercise swimming group (n=10 ). Then the glutamine was given to supplementation group and the placebo was given to the control group, both groups began to swim for 4 weeks. Studied variables including lactate levels, fatigue and athletic performance index were measured before and after the study.  The results showed that use of glutamine amino acids led to a significant reduction in the fatigue index and produced lactate in the supplementation group compared to the placebo group. The time of athletes' performance wasn’t significantly increased.  The results showed the glutamine supplementation in areas such as swimming where the athlete must take part in a day in several competition, has a significant impact on the reduction of blood lactate concentration and more endurance of athletes than accumulation of lactic acid and reduction of swimming athletes fatigue index . However, more research is needed in this area

Heart rate and lactate responses to taekwondo fight in elite women performers

The purpose of this study was to examine heart rate (HR) and blood lactate (LA) concentration before, during and after a competitive Tae kwon do (TKD) fight performed by elite women performers. Specifically, we were interested to see weather HR and LA responses to competitive fight were greater than to TKD or karate exercises published in scientific literature. Seven international-standard women TKD fighters participated in the study. HR was recorded continuously throughout the fight using Polar Vantage telemetric HR monitors. LA samples were taken before and 3 min after the fight and analysed using an Accusport portable lactate analyzer. At the beginning of the fight, HR significantly increased (p<0.01) from pre-fight values of 91.6±9.9 beats min-1 to 144.1±13.6 beats min-1. During the whole fight the HRmean was 186.6±2.5 beats min-1 and remained significantly elevated (p<0.01) at 3 min into recovery. HR values expressed as a percentage of HRmax averaged during the whole fight at 91.7±2.6% respectively. LA concentration significantly increased (p<0.01) 3 min after the fight and averaged 82% of LApeak values measured after the VO2max test. Results of the present study indicate that physiological demands of competitive TKD fight in women, measured by HR and LA responses, are considerably higher than the physiological demands of TKD or karate training exercises. The observed HR and LA responses suggest to us that conditioning for TKD should generally emphasise high-intensity anaerobic exercise