Markers Of Skeletal Muscle Damage Research Articles

Thermographic Assessment of Skin Temperature Changes following Partial Body Cryostimulation (PBC) in Football Players

Infrared thermography has been widely used to visualize skin temperature in human science. One of the important areas of its application is the analysis of changes in body surface temperature as a result of the use of physical medicine treatments in post-exercise regeneration in sports. The aim of this study was to evaluate the cutaneous temperature response in selected body areas and the range of chosen markers of skeletal muscle damage to partial body cryostimulation (PBC) as a method of post-match regeneration. Fourteen football players underwent PBC after a match. Thermographic analyses of anterior and posterior surfaces of the body were performed before and immediately after the treatment. Before, directly after, and 24, 48, and 72 h after the match serum creatine kinase (CK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) were evaluated. After PBC, a significant (p ≤ 0.001) decrease in skin temperature (Tsk) in all analyzed areas occurred. The greatest drop was observed in the areas of the thighs (∆ = 9.96–11.02 °C); the smallest temperature drop occurred in the areas of the upper and lower part of the back (∆ = 6.18−6.70 °C) and in the area of the chest (∆ = 6.80 °C). The most significant positive relationships between the magnitude of change in Tsk of the anterior and posterior surfaces of the thighs, body fat, and systolic and diastolic blood pressure have been shown. There were no significant differences between temperatures in selected areas in relation to the sides of the body, both before and after PBC. The range of temperature changes confirms the stimulating effect of PBC. The course of changes in the concentration of CK and AST indicates a potentially beneficial effect of PBC on the course of post-workout regeneration, without side effects. Maintaining a constant body temperature during PBC comes at the expense of thermoregulatory mechanisms leading to a lower body surface temperature.

Characteristics of <i>m. Psoas minor</i> and <i>m. Sacrocaudalis (coccygeus)</i> dorsalis lateralis in simultaneous modeling of lateral interbodial spinnylodesis and posterior sacro-iliac joint arthodesis

BACKGROUND: Simultaneous surgical interventions on the spine with the use of high-tech instruments and minimally invasive access techniques allow to eliminate several problems all at once, to activate patients at an early date and to reduce the number of complications. AIM: To evaluate morphological changes to evaluate morphological changes in the m. Psoas minor and m. Sacrocaudalis dorsalis lateralis during simultaneous modeling of lateral interbody fusion and posterior sacroiliac joint arthrodesis MATERIALS AND METHODS: Experiments were carried out on 14 outbred dogs; 3 animals formed a control group. The animals underwent consecutive lateral interbody fusion of the lumbar spine and posterior arthrodesis of the sacroiliac joint. The lumbar spine and sacroiliac joint were stabilized with external fixation device. Paraffin sections of muscles were stained with hematoxylin-eosin, according to Van Gieson, and Masson. Biochemical analysis of blood serum was performed during the experiment. RESULTS: The morphological study of the muscles revealed pathohistological features such as an increase in the variety of myosymplast diameters, loss of their profiles polygonality, massive fibers fatty degeneration, endo- and perimysial fibrosis, sclerotization of vessel membranes, obliteration of their lumens. At the end of the experiment, the degree of the small lumbar muscle fibrosis was 161% and of the sacrocaudal dorsal lateral muscle fibrosis was 240% of the control parameters (p 0.05); the rate of the muscle fatty infiltration was 339 and 310% of the normal value, respectively. The sacroiliac-caudal dorsal lateral muscle underwent more marked changes, especially in the early stages of the experiment. A significant increase in the enzymes activity, skeletal muscle damage markers was detected on the 14th day after surgery. CONCLUSION: Simultaneous surgical interventions on the spine should minimize mechanical effects on the paravertebral muscles and use techniques to stimulate their function in the postoperative period, which will reduce the processes of fibrogenesis and fat involution as well as provide an overall shorter rehabilitation period for the target patients.

Functional and biochemical characteristics of the muscle system in children with type I diabetes

Background. The purpose of the study was to determine possible markers of skeletal muscle damage in children with type 1 diabetes mellitus (T1DM) and their relationship with the features of disease course. Materials and methods. The observation group consisted of 98 children with type 1 diabetes mellitus: the first group included 22 people without disorders of the muscular system; the second — 42 patients with dynapenia; the third — 34 children with diabetic myopathy. Control group — 30 relatively healthy children. Assessment of the static endurance of skeletal muscles, determination of the level of creatine kinase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, periostin and cardiotrophin-1 in blood serum were performed in all patients. Results. The conducted studies demonstrate that children with diabetes, regardless of the structural and functional state of their muscular system, have signs of skeletal muscle damage, which were most expressed in diabetic myopathy and progressed with maximal deterioration of glycemic control. It was found that the highest content of alkaline phosphatase was characteristic of children from group 1, while in patients with diabetic myopathy its serum content was not statistically different from that of controls. These disorders occurred against the background of changes in alkaline phosphatase activity, the level of which was highest in children from group 1, while in patients with diabetic myopathy, its serum content was not statistically different from that of controls. At the same time, during the course of diabetic myopathy in children with T1DM, there was an increase in lactate dehydrogenase activity by 1.2 times (p < 0.01) and cardiotrophin-1 by 300 times (p < 0.01) compared to the corresponding indicator of the control group. Serum periostin level was increased in all patients with T1DM. Its maximum values were determined in group 1, whose periostin concentration exceeded control indicators by 103 times (p < 0.01). With deterioration of skeletal muscle state, there was a gradual decrease in periostin serum level, but in patients with dynapenia, it was 35.5 times higher than in the control group (p < 0.05) and 19.2 times higher in those with diabetic myopathy (p < 0.05). Conclusions. The course of type 1 diabetes in children is accompanied by skeletal muscle damage, the first clinical sign of which is a decrease in the static muscle endurance against the background of worsening disease course. Alkaline phosphatase, lactate dehydrogenase, periostin, and cardiotrophin-1 are biochemical markers of skeletal muscle damage in children with type 1 diabetes. A common feature of the changes in the specified indicators is their increase; however, each clinical condition of the skeletal muscles corresponds to its own configuration of changes in the abovementioned markers.

Protective Effect of D-Panthenol in Rhabdomyolysis-Induced Acute Kidney Injury.

We investigated the nephroprotective effect of D-panthenol in rhabdomyolysis-induced acute kidney injury (AKI). Adult male Wistar rats were injected with 50% glycerol solution to induce rhabdomyolysis. Animals with rhabdomyolysis were injected with D-panthenol (200 mg/kg) for 7 days. On day 8, we examined AKI markers, renal histology, antioxidant capacity, and protein glutathionylation in kidneys to uncover mechanisms of D-panthenol effects. Rhabdomyolysis kidneys were shown to have pathomorphological alterations (mononuclear infiltration, dilatation of tubules, and hyaline casts in Henle’s loops and collecting ducts). Activities of skeletal muscle damage markers (creatine kinase and lactate dehydrogenase) increased, myoglobinuria was observed, and creatinine, BUN, and pantetheinase activity in serum and urine rose. Signs of oxidative stress in the kidney tissue of rhabdomyolysis rats, increased levels of lipid peroxidation products, and activities of antioxidant enzymes (SOD, catalase, and glutathione peroxidase) were all alleviated by administration of D-panthenol. Its application improved kidney morphology and decreased AKI markers. Mechanisms of D-panthenol’s beneficial effects were associated with an increase in total coenzyme A levels, activity of Krebs cycle enzymes, and attenuation of protein glutathionylation. D-Panthenol protects kidneys from rhabdomyolysis-induced AKI through antioxidant effects, normalization of mitochondrial metabolism, and modulation of glutathione-dependent signaling.

Modulation of Leukocyte Subsets Mobilization in Response to Exercise by Water Immersion Recovery.

Purpose: To investigate the effect of different water immersion temperatures on the kinetics of blood markers of skeletal muscle damage and the main leukocyte subpopulations. Methods: Eleven recreationally trained young men participated in four experimental sessions consisting of unilateral eccentric knee flexion and 90 min of treadmill running at 70% of peak oxygen uptake, followed by 15 min of water immersion recovery at 15, 28 or 38°C. In the control condition participants remained seated at room temperature. Four hours after exercise recovery, participants completed a performance test. Blood samples were obtained before and immediately after exercise, after immersion, immediately before and after the performance test and 24 h after exercise. The number of leukocyte populations and the percentage of lymphocyte and monocytes subsets, as well as the serum activity of creatine kinase and aspartate aminotransferase were determined. Results: Leukocytosis and increase in blood markers of skeletal muscle damage were observed after the exercise. Magnitude effect analysis indicated that post-exercise hot-water immersion likely reduced the exercise-induced lymphocytosis and monocytosis. Despite reduced monocyte count, recovery by 38°C immersion, as well as 28°C, likely increased the percentage of non-classical monocytes in the blood. The percentage of CD25+ cells in the CD4 T cell subpopulation was possibly lower after immersion in water at 28 and 15°C. No effect of recovery by water immersion was observed for serum levels of creatine kinase and aspartate aminotransferase. Conclusions: Recovery by hot-water immersion likely attenuated the leukocytosis and increased the mobilization of non-classical monocytes induced by a single session of exercise combining resistance and endurance exercises, despite no effect of water immersion on markers of skeletal muscle damage. The monocyte response mediated by hot water immersion may lead to the improvement of the inflammatory response evoked by exercise in the skeletal muscle.

Time Course and Role of Exercise-Induced Cytokines in Muscle Damage and Repair After a Marathon Race.

Endurance exercise induces an increase in the expression of exercise-induced peptides that participate in the repair and regeneration of skeletal muscles. The present study aimed to evaluate the time course and role of exercise-induced cytokines in muscle damage and repair after a marathon race. Fifty-seven Brazilian male amateur marathon finishers, aged 30–55 years, participated in this study. The blood samples were collected 24 h before, immediately after, and 24 and 72 h after the São Paulo International Marathon. The leukogram and muscle damage markers were analyzed using routine automated methodology in the clinical laboratory. The plasma levels of the exercise-induced cytokines were determined using the Human Magnetic Bead Panel or enzyme-linked immunosorbent assays [decorin and growth differentiation factor 15 (GDF-15)]. A muscle damage was characterized by an increase in plasma myocellular proteins and immune changes (leukocytosis and neutrophilia). Running the marathon increased interleukin (IL)-6 (4-fold), IL-8 (1.5-fold), monocyte chemoattractant protein-1 (2.4-fold), tumor necrosis factor alpha (TNF-α) (1.5-fold), IL-10 (11-fold), decorin (1.9-fold), GDF-15 (1.8-fold), brain-derived neurotrophic factor (BDNF) (2.7-fold), follistatin (2-fold), and fibroblast growth factor (FGF-21) (3.4-fold) plasma levels. We also observed a reduction in musclin, myostatin, IL-15, and apelin levels immediately after the race (by 22–36%), 24 h (by 26–52%), and 72 h after the race (by 25–53%). The changes in BDNF levels were negatively correlated with the variations in troponin levels (r = −0.36). The variations in IL-6 concentrations were correlated with the changes in follistatin (r = 0.33) and FGF-21 (r = 0.31) levels after the race and with myostatin and irisin levels 72 h after the race. The changes in IL-8 and IL-10 levels had positive correlation with variation in musclin (p < 0.05). Regeneration of exercise-induced muscle damage involves the participation of classical inflammatory mediators, as well as GDF-15, BDNF, follistatin, decorin, and FGF-21, whose functions include myogenesis, mytophagia, satellite cell activation, and downregulation of protein degradation. The skeletal muscle damage markers were not associated to myokines response. However, BDNF had a negative correlation with a myocardial damage marker. The classical anti-inflammatory mediators (IL-10, IL-8, and IL-6) induced by exercise are associated to myokines response immediately after the race and in the recovery period and may affect the dynamics of muscle tissue repair.

The Impulse of Force as an Effective Indicator of Exercise Capacity in Competitive Rowers and Canoeists.

The aim of the research was to present the importance of measuring the impulse of force in assessing exercise capacity in professional rowers and canoeists rather than conducting traditional physiological and biochemical analyses. A group of 20 athletes (12 rowers and 8 canoeists) underwent progressive intensity exercise tests in two testing sessions (before and after a training period). During the tests, maximal aerobic capacity, impulse of strength, metabolic indices, and markers of skeletal muscle damage were assessed. Total testosterone, free testosterone, cortisol, interleukin 1,6, and creatine kinase were evaluated in venous blood. The impulse of force at the ventilatory threshold and at the maximum load was correlated with free testosterone and a total testosterone/cortisol ratio during exercise (p ≤ 0.05) and was negatively correlated with cortisol concentration (p ≤ 0.05) in the first testing session (before training intervention). Values were positively correlated with concentration of total testosterone, free testosterone and total testosterone/cortisol, and free testosterone/cortisol ratios during exercise (p ≤ 0.05) in the second testing session (after training intervention). Biochemical indices of overtraining were correlated with maximum oxygen uptake in each session and with the impulse of force at the ventilatory threshold and the maximum load of exercise. Thus, there is an indirect relationship between maximal aerobic capacity and the impulse of force. The measurement of the impulse of force can become a simple and effective method for evaluating the overall exercise capacity of rowers because of its relationship with indices of the load and changes in hormonal indices of anabolic and catabolic processes during exercise. Therefore, it may constitute a replacement for the traditional laboratory measurement of VO2max in highly qualified rowers and canoeists.

Effect of short-term physical exercise on serum markers of skeletal muscle damage in hypertensive patients treated with a combination of statin and angiotensin-converting enzyme inhibitor

Background. Muscle strain during physical exercise may lead to muscle damage and hyperkalaemia. Commonly prescribed drugs including statins and angiotensin-converting enzyme inhibitors (ACEI) may increase serum potassium and cause muscle damage. We postulated that the risk may be even higher if the patients are treated with a combination of statin and ACEI. The aim of the study was to compare the effect of moderate intensity short-term physical exercise on the changes of muscle injury markers serum carbonic anhydrase 3 and creatine kinase in patients with arterial hypertension receiving ACEI and statin. Material and methods. Eighteen patients with arterial hypertension treated with ACEI were included in a prospective placebo-controlled cross-over study. 18 healthy individuals served as controls. Hypertensive patients underwent 30-minute exercise test, which was repeated two times in a random order after the administration of ACEI with statin or ACEI with placebo. Each treatment period lasted 8 weeks separated by 2-week wash-out. Normotensive subjects underwent a single exercise test. Serum carbonic anhydrase 3 (CAIII) and creatine kinase (CK) activity were measured before and after exercise and recovery. Results. At baseline and during the exercise CAIII was significantly higher in healthy volunteers compared to hypertensive patients. CAIII increased significantly during exercise only after treatment with both ACEI and statin. Serum CK was higher in hypertensive patients treated with ACEI plus statin during all exercise tests. Conclusions. Addition of statin to ACEI in patients with arterial hypertension does not increase the risk of muscle damage during moderate intensity short-term physical exercise.

Acute effects of recreational soccer on inflammatory response and cardiac and skeletal muscle damage indicators

Abstract Introduction: Previous studies have indicated that acute bouts of strenuous, long duration exercise induce significant increases in the inflammatory profile and cardiovascular risk markers. Although recreational soccer (RS) is a widespread activity, there are no data on this topic. Thus, the aim of this study was to examine RS-induced changes in inflammatory, cardiac, and skeletal muscle damage indicators in young and middle-aged males. Methods: Twelve young and 11 middle-aged males participated in the study. The participants played 6v6 1 h RS, where heart rate (HR) responses and external loads (distance covered, number of accelerations/decelerations) were determined. Blood samples were taken immediately prior to and following the matches, and 2 h, 4 h, 24 h, 48 h, and 72 h later. Results: Absolute HR responses and the number of accelerations and decelerations were higher in young participants than the middle-aged participants (p &lt; 0.05). RS increased high sensitivity cardiac troponin I (hs-cTnI) in almost all participants. A total of 83.3% of the young participants exceeded the upper reference limit (URL), whereas none of the middle-aged participants exceeded the URL. Hs-cTnI levels returned to baseline after 24 and 48 h in the middle-aged and young participants, respectively. High sensitivity C-reactive protein (hs-CRP) and creatine kinase (CK) increased in the middle-aged participants (p &lt; 0.05), and in the young participants, though not significantly (p &gt; 0.05). RS also led to significant increases in lactate dehydrogenase (LDH) in both groups (p &lt; 0.05). Hs-CRP, CK, and LDH values returned to baseline levels within 48 to 72 h, except for the LDH values of the young participants. Conclusion: RS induced short-term increases in cardiac and skeletal muscle damage markers and the inflammatory profile in young and middle-aged RS participants.

Does exercising at a certain time-of-day affect athletes skeletal muscle damage markers? A systematic review and meta-analysis

The objective of the study was to examine time of day effects of exercise on athletes’ skeletal muscle damage markers. The skeletal muscle damage marker enzymes like creatine kinase, lactate dehydr...

Effects of bilateral or unilateral lower body resistance exercises on markers of skeletal muscle damage

BackgroundIt is known that different intensity exercises create skeletal muscle damage at different levels. The purpose of the study was to compare effects of bilateral or unilateral lower body resistance exercise on markers of skeletal muscle damage. MethodsThe Brzycki Formula was used to calculate participants' one repetition maximum strength for each movement and limb, separately. Blood samples were obtained before exercise, immediately after exercise, and 30 min after exercise for both types of exercise. Creatine Kinase (CK), Lactate Dehydrogenase (LDH), Aspartate Aminotransferase (AST), and Alanine Aminotransferase (ALT) levels were analyzed. Data was analyzed using two-way repeated measures ANOVA. ResultsWhen CK, AST, and ALT levels were compared according to time points, a statistical difference was found (p < 0.05). Furthermore, it was revealed that LDH levels were statistically significant according to exercise types (p < 0.05). ConclusionUnilateral lower body resistance exercise caused higher skeletal muscle damage than the bilateral lower body resistance exercise. This result suggests that unilateral lower body resistance exercise should be preferred for short preparation period as opposed to bilateral lower body resistance exercise.

Skeletal Muscle Cell Damage Indicators in Volleyball Players after the Competitive Phase of the Annual Training Cycle.

The aim of the study was to evaluate the impact of the competitive phase on physiological and metabolic indices and selected markers of skeletal muscle damage in male volleyball players. The study group consisted of 24 young male volleyball players. During the study, participants underwent two series of measurements, before and after the competitive phase of the annual training cycle. In both study terms, players performed an incremental treadmill running test to determine their ventilatory threshold and maximal oxygen uptake. Venous and capillary blood samples were taken for biochemical analysis. There was no significant difference in the physical fitness level, values of biochemical variables and the level of antioxidant status in the surveyed athletes between the two study terms. Significant changes within skeletal muscle damage markers were observed between the beginning and the end of the competitive period: an increase in the concentration of cellular DNA damage products (8-hydroxy-2′-deoxyguanosine; p < 0.0001) and a decrease in muscle activity of creatine kinase (p<0.05). In spite of the increment in cell damage markers, the unaffected level of physiological and biochemical markers may indicate that the experienced cell destruction did not negatively affect the level of physical fitness. When designing the annual training plan, coaches and athletes need to take into consideration that temporary physiological states – oxidative stress and inflammation – may be required to attain training adaptation.

Ursolic acid supplementation decreases markers of skeletal muscle damage during resistance training in resistance-trained men: a pilot study.

Ursolic acid (UA) supplementation was previously shown to improve skeletal muscle function in resistance-trained men. This study aimed to determine, using the same experimental paradigm, whether UA also has beneficial effects on exercise-induced skeletal muscle damage markers including the levels of cortisol, B-type natriuretic peptide (BNP), myoglobin, creatine kinase (CK), creatine kinase-myocardial band (CK-MB), and lactate dehydrogenase (LDH) in resistance-trained men. Sixteen healthy participants were randomly assigned to resistance training (RT) or RT+UA groups (n=8 per group). Participants were trained according to the RT program (60~80% of 1 repetition, 6 times/week), and the UA group was additionally given UA supplementation (450 mg/day) for 8 weeks. Blood samples were obtained before and after intervention, and cortisol, BNP, myoglobin, CK, CK-MB, and LDH levels were analyzed. Subjects who underwent RT alone showed no significant change in body composition and markers of skeletal muscle damage, whereas RT+UA group showed slightly decreased body weight and body fat percentage and slightly increased lean body mass, but without statistical significance. In addition, UA supplementation significantly decreased the BNP, CK, CK-MB, and LDH levels (p<0.05). In conclusion, UA supplementation alleviates increased skeletal muscle damage markers after RT. This finding provides evidence for a potential new therapy for resistance-trained men.

Control of antioxidant supplementation through interview is not appropriate in oxidative-stress sport studies: Analytical confirmation should be required

ObjectiveControlling antioxidant supplementation in athletes involved in studies related to oxidative stress and muscle damage is the key to ensure results. The aim of this study was to confirm through high-performance liquid chromatography (HPLC) analysis whether well-trained individuals lied during a personal interview when asked if they were taking supplements with antioxidants, and how this could affect oxidative stress, muscle damage, and antioxidant response. MethodsA total of 94 men, well trained in endurance sports, volunteered in this study. They denied taking any antioxidant supplementation at initial interview. After a HPLC analysis, abnormal α-tocopherol concentrations were detected, probably due to a hidden antioxidant supplementation. Participants were classified into two groups: no evidence of antioxidant supplementation (NS group = α-tocopherol values <80 nmol/mL; n = 75) and evidence of antioxidant supplementation (S group = α-tocopherol values >80 nmol/mL; n = 19). Lipid peroxidation, muscle damage, antioxidant enzyme activity, and nonenzymatic antioxidant content were analyzed according to this classification. Statistical comparisons were performed using Student's t test. ResultsThe α-tocopherol concentrations were significantly higher in the S group than in the NS group (MD = 725.01 ± 39.01 nmol/mL; P = 0.001). The S group showed a trend toward lower hydroperoxides than the NS group (MD = 1.19 ± 0.72 nmol/mL; P = 0.071). The S group showed significantly lower catalase activity than the NS group (MD = 0.10 ± 0.02-seg-1 mg-1; P < 0.01). Skeletal muscle damage markers did not differ between experimental groups. ConclusionsData from the present study reveal that 20% of participants lied in the exclusion criteria of antioxidant supplementation in a personal interview, as they showed high plasmatic α-tocopherol concentrations after HPLC verification. Catalase activity seems to be affected by high α-tocopherol plasma levels. Therefore, we strongly recommend the HPLC analysis as a necessary tool to verify the antioxidant intake and preserve results in studies linking oxidative stress and sport.

Vitamin D3 Reduces Tissue Damage and Oxidative Stress Caused by Exhaustive Exercise

Exhaustive exercise results in inflammation and oxidative stress, which can damage tissue. Previous studies have shown that vitamin D has both anti-inflammatory and antiperoxidative activity. Therefore, we aimed to test if vitamin D could reduce the damage caused by exhaustive exercise. Rats were randomized to one of four groups: control, vitamin D, exercise, and vitamin D+exercise. Exercised rats received an intravenous injection of vitamin D (1 ng/mL) or normal saline after exhaustive exercise. Blood pressure, heart rate, and blood samples were collected for biochemical testing. Histological examination and immunohistochemical (IHC) analyses were performed on lungs and kidneys after the animals were sacrificed. In comparison to the exercise group, blood markers of skeletal muscle damage, creatine kinase and lactate dehydrogenase, were significantly (P < 0.05) lower in the vitamin D+exercise group. The exercise group also had more severe tissue injury scores in the lungs (average of 2.4 ± 0.71) and kidneys (average of 3.3 ± 0.6) than the vitamin D-treated exercise group did (1.08 ± 0.57 and 1.16 ± 0.55). IHC staining showed that vitamin D reduced the oxidative product 4-Hydroxynonenal in exercised animals from 20.6% to 13.8% in the lungs and from 29.4% to 16.7% in the kidneys. In summary, postexercise intravenous injection of vitamin D can reduce the peroxidation induced by exhaustive exercise and ameliorate tissue damage, particularly in the kidneys and lungs.

Effects of probiotic supplementation on markers of skeletal muscle damage, perceived recovery and athletic performance after an intense single leg training bout

The probiotic GanedenBC30 (Bacillus coagulans GBI-30, 6086; Ganeden Biotech Inc., Maryfield Heights, OH) has been shown to support healthy digestive and immune function, including increased protein absorption. In a pilot study, daily co-administration of GanedenBC30 and protein in resistance-trained subjects performing full body workouts 4 times per week for 8 weeks has shown a trend to increase vertical jump power and might have a beneficial effect on peak power and fat mass. We speculate that the beneficial effects might be based on aiding muscle recovery through gut microbial modulation. Thus, the purpose of this investigation was to determine if the co-administration of GanedenBC30 with protein has a beneficial effect on muscle damage, recovery and athletic performance following a damaging exercise bout.

The Effects of Sprint Interval vs. Continuous Endurance Training on Physiological And Metabolic Adaptations in Young Healthy Adults.

The purpose of this study was to compare the effects of sprint interval training (SIT) and continuous endurance training (CET) on selected anthropometric, aerobic, and anaerobic performance indices as well as the blood lipid profile, inflammatory and muscle damage markers in healthy young males. Fifteen recreationally active male volunteers (age: 21.7 ±2.2 years, body mass: 83.0 ±8.0 kg, body height: 1.82 ±0.05 m) were divided into two groups according to their initial VO2max levels. Training programs were conducted 3 times per week for 7 weeks. The SIT program consisted of 4–6 Wingate anaerobic sprints with a 4.5 min recovery, while CET consisted of 30–50 min cycling at 60% VO2max. Biochemical, anthropometric and fitness assessments were performed both pre and post-intervention. Significant improvements in VO2max, anaerobic power and capacity, and VO2 utilization during the submaximal workout and significant decreases in body fat and in waist circumference after the intervention occurred in both SIT and CET groups. Significantly greater gross efficiency was measured in the CET group. No differences in the lipid profile or serum levels of inflammatory, myocardial and skeletal muscle damage markers were observed after the training period. The study results agree with the effectiveness of a 30 s all-out training program with a reduced time commitment for anthropometric, aerobic and anaerobic adaptation and eliminate doubts about its safety as a model.

Allopurinol prevents cardiac and skeletal muscle damage in professional soccer players

Xanthine oxidase (XO), a free radical-generating enzyme, is involved in tissue damage produced during exhaustive exercise. Our aim was to test whether allopurinol, a powerful inhibitor of XO, may be effective in preventing exercise-induced tissue damage in soccer players. Twelve soccer players were randomized into two experimental groups. One received allopurinol, before a match of the premier Spanish Football League, and the other placebo. Allopurinol prevented the exercise-induced increase in all the markers of skeletal muscle damage analyzed: creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and myoglobin. Creatine kinase-MB isoenzyme and highly sensitive troponin T, specific biomarkers of myocardial injury, increased significantly in the placebo but not in the allopurinol-treated group after the football match. We also found that the exercise-induced lipid peroxidation, as reflected by malondialdehyde measurements, was prevented after allopurinol administration. However, inhibition of XO did not prevent the increment in the activity of alanine aminotransferase found after the match. No changes in the serum gamma glutamyltransferase activity was found after the match on either the placebo and the allopurinol groups. These two enzymes were determined as biomarkers of liver injury. Allopurinol represents an effective and inexpensive pharmacological agent to prevent tissue damage in soccer players.

Influence of vitamin D mushroom powder supplementation on exercise-induced muscle damage in vitamin D insufficient high school athletes

Incidence of vitamin D deficiency is increasing worldwide. The purpose of this study was to determine if supplementation with vitamin D2 from Portobello mushroom powder would enhance skeletal muscle function and attenuate exercise-induced muscle damage in low vitamin D status high school athletes. Participants were randomised to Portobello mushroom powder (600 IU/d vitamin D2) or placebo for 6 weeks. Participants then completed a 1.5-h exercise session designed to induce skeletal muscle damage. Blood samples and measures of skeletal muscle function were taken pre-supplementation, post-supplementation/pre-exercise and post-exercise. Six weeks supplementation with vitamin D2 increased serum 25(OH)D2 by 9.9-fold and decreased serum 25(OH)D3 by 28%. Changes in skeletal muscle function and circulating markers of skeletal muscle damage did not differ between groups. In conclusion, 600 IU/d vitamin D2 increased 25(OH)D2 with a concomitant decrease in 25(OD)D3, with no effect on muscular function or exercise-induced muscle damage in high school athletes.

Comparison of Acute Responses to Isotonic or Isokinetic Eccentric Muscle Action: Differential Outcomes in Skeletal Muscle Damage and Implications for Rehabilitation

Both isotonic and isokinetic eccentric muscle contractions are commonly used in muscle research laboratories to induce muscle damage, yet, the muscle damage outcomes between these 2 modes of eccentric contraction have not been compared. The purpose of this study was to compare modes of contraction for differences in muscle damage. 16 men were placed in the isotonic (IT: 110% of maximal isometric torque) or the isokinetic (IK: 120°/s) group, with each group performing 200 eccentric muscle actions of the knee extensors. Isometric peak torque, perceived soreness and CK activity were measured immediately pre and post exercise, and 48-h post exercise. Mean total work (~1700 J) and peak torque per set (~265 Nm) decreased over the 200 repetitions (p<0.01), and was not different between groups. Damage markers changed 48-h post exercise (p<0.05): peak isometric torque (-13%), creatine kinase activity (+200%) and self-perceived muscular soreness (+4 unit change). Significant group×time interactions (p<0.01) indicated that peak isometric torque was 22% lower, and creatine kinase and self-perceived muscular soreness were 330% and 3 unit difference higher in the IT as compared to the IK groups, 48-h post exercise. When equating for total work, skeletal muscle damage markers are higher during IT vs. IK modes. This reflects differences inherent in contraction type and suggests that this should be taken into account during physical rehabilitation.