Publications (34)92.88 Total impact
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Article: α-Lipoic acid supplementation up-regulates antioxidant capacity in adults with G6PD deficiency.
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ABSTRACT: The purpose of this study was to examine the effect of α-lipoic acid (LA) supplementation on blood redox status in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Eight adults with G6PD deficiency (D group) and eight controls with normal G6PD levels (N group) participated in this study. Participants received LA (600mg/day) for 28days. At baseline, 2 and 4weeks after supplementation, venous blood was collected for analysis of reduced glutathione (GSH), catalase, protein carbonyls (PC), thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), bilirubin, uric acid (UA) and hemoglobin (Hb) levels. Baseline GSH was lower (P<0.05) in D compared to N group whereas LA supplementation for 2 and 4weeks increased significantly (P<0.05) GSH levels in both groups. Catalase and TAC increased (P<0.05) in both groups following 2 and 4weeks of supplementation. Baseline TBARS values were higher (P<0.05) in D compared to N group while LA supplementation reduced (P<0.05) TBARS and PC in both groups. There were no differences for UA at baseline between the two groups but LA supplementation increased significantly UA levels only in the D group. Bilirubin and Hb were unchanged. These results indicate that LA supplementation may modulate redox status regardless G6PD deficiency.Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 02/2013; · 2.99 Impact Factor -
Article: Oxidative stress and inflammatory responses following an acute bout of isokinetic exercise in obese women with knee osteoarthritis.
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ABSTRACT: BACKGROUND: Obesity is associated with osteoarthritis and it is accompanied by chronic inflammation and elevated oxidative stress. Strengthening-type exercise is used in knee osteoarthritis (KOA) rehabilitation. This study determined how acute isokinetic exercise influences inflammatory responses of obese middle-aged women with KOA. METHODS: Ten obese women with KOA and 10 age/weight-matched controls performed an isokinetic exercise protocol. Assessment of performance (knee extensor/flexor torque), muscle soreness (DOMS), knee flexibility (KJRM), and pain, and blood collection were performed pre-exercise, post-exercise, and at 24h post-exercise. Blood was analyzed for creatine kinase activity (CK), lactate dehydrogenase activity (LDH), CRP, leukocytes, uric acid, IL-6, TBARS, lipid hydroperoxides (LPX), protein carbonyls (PC), oxidized (GSH) and reduced glutathione (GSSG), total antioxidant capacity (TAC), catalase activity, and glutathione peroxidase activity (GPX). RESULTS: Physical function remained unaltered by exercise (only torque at 90°/s decreased at 24h). Exercise increased DOMS throughout recovery but KJRM and pain remained unchanged. CK, LDH, and uric acid increased similarly in both groups. CRP remained unaffected by exercise while IL-6 increased only post-exercise. TBARS, PC, LPH, GSSG, and TAC increased only post-exercise in both groups. GSH and GSH/GSSG declined post-exercise and normalized thereafter. Catalase and GPX increased only in patients post-exercise. CONCLUSION: Isokinetic exercise induces only a mild inflammatory response of very short duration (<24h) without affecting physical function and pain in KOA patients suggesting that moderate strengthening-type exercise may be safe for this patient cohort. These results indicate that KOA patients may be able to receive another exercise stimulus after only 48h. CLINICAL RELEVANCE: Isokinetic exercise produces minimal inflammation and pain in knee osteoarthritis patients, could be performed every 48h during rehabilitation, and up-regulates patients' antioxidant system.The Knee 12/2012; · 1.74 Impact Factor -
Article: Adipocytokine levels in children: effects of fatness and training.
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ABSTRACT: To investigate the effects of obesity and exercise training on plasma adipocytokines a sample of 42 children (lean = 24, %BF = 17.8 ± 7.5%; obese = 18; %BF = 29.1 ± 9.3%; mean age = 12.4 ± 1.9 yrs), were divided into 4 age-matched for activity groups: lean inactive (n = 11), obese inactive (n = 9), lean active (n = 13) and obese active (n = 9). Active children participated in swimming training (≥1 year, ≥3 times/week, ≥1 h per session, covering a distance of 10,000-12,000 m per week).Obese individuals demonstrated greater visfatin levels (3.3 ± 1.3 ng/ml) than their lean counterparts (2.6 ± 1.1 ng/ml; p = .06) whereas adiponectin was significantly lower in obese children (3.8 ± 1.9) than their lean counterparts (5.9 ± 2.7; p £ .05). Insulin and HOMA values were significantly greater in obese compared with lean children (p £ .05). Within obese individuals, active individuals had significantly lower visfatin levels (2.8 ± 1.2 ng/ml) compared with their inactive counterparts (3.8 ± 1.2 ng/ml; p £ .05). Resistin levels were comparable between groups (p > .05). Childhood obesity elevates visfatin and lowers adiponectin levels whereas exercise training could reduce visfatin levels in obese children.Pediatric exercise science 08/2012; 24(3):461-71. · 1.71 Impact Factor -
Article: Plyometrics' Trainability in Pre-Adolescent Soccer Athletes.
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ABSTRACT: Plyometric training (PT) is a widely used method to improve muscles' ability to generate explosive power. This study aimed to determine whether pre-adolescent boys exhibit plyometric trainability or not. Forty-five children were randomly assigned to either a control (CG, N=21, 10.6±0.5 yrs; participated only in regular soccer practice) or a plyometric training group (PTG, N=24, 10.6±0.6 yrs; participated in regular soccer practice plus a plyometric exercise protocol). Both groups trained for 12 weeks during the in-season period. PT exercises (forward hopping, lateral hopping, shuffles, skipping, ladder drills, skipping, box jumps, low-intensity depth jumps) were performed twice a week. Pre-adolescence was verified by measuring Tanner stages, bone age, and serum testosterone. Speed (0-10 m, 10-20 m, 20-30 m), leg muscle power [static jumping (SJ), countermovement jumping (CMJ), depth jumping (DJ), standing long jump (SLJ), multiple 5-bound hopping (MB5)], leg strength (10RM), anaerobic power (Wingate testing), and soccer specific performance (agility, kicking distance) were measured at baseline, mid- and post-training. CG caused only a modest (1.2%-1.8%) increase in speed post-training. PTG induced a marked (p<0.05) improvement in all speed tests (1.9%-3.1% at mid-training and 3-5% at post-training) and vertical jump tests (10%-18.5% at mid-training and 16-23% at post-training), SLJ (2.6% at mid-training and 4.2% at post-training), MB5 (14.6% at mid-training and 23% at post-training), leg strength (15% at mid-training and 28% at post-training), agility (5% at mid-training and 23% at post-training), and kicking distance (13.6% at mid-training and 22.5% at post-training). Anaerobic power remained unaffected in both groups. These data indicate that: a) pre-pubertal boys exhibit considerable plyometric trainability, and b) when soccer practice is supplemented with a plyometric training protocol it leads to greater performance gains.The Journal of Strength and Conditioning Research 03/2012; · 1.83 Impact Factor -
Article: The effects of aging, physical training, and a single bout of exercise on mitochondrial protein expression in human skeletal muscle.
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ABSTRACT: Aging results in a significant decline in aerobic capacity and impaired mitochondrial function. We have tested the effects of moderate physical activity on aerobic capacity and a single bout of exercise on the expression profile of mitochondrial biogenesis, and fusion and fission related genes in skeletal muscle of human subjects. Physical activity attenuated the aging-associated decline in VO2 max (p<0.05). Aging increased and a single exercise bout decreased the expression of nuclear respiratory factor-1 (NRF1), while the transcription factor A (TFAM) expression showed a strong relationship with VO(2max) and increased significantly in the young physically active group. Mitochondrial fission representing FIS1 was induced by regular physical activity, while a bout of exercise decreased fusion-associated gene expression. The expression of polynucleotide phosphorylase (PNPase) changed inversely in young and old groups and decreased with aging. The A2 subunit of cyclic AMP-activated protein kinase (AMPK) was induced by a single bout of exercise in skeletal muscle samples of both young and old subjects (p<0.05). Our data suggest that moderate levels of regular physical activity increases a larger number of mitochondrial biogenesis-related gene expressions in young individuals than in aged subjects. Mitochondrial fission is impaired by aging and could be one of the most sensitive markers of the age-associated decline in the adaptive response to physical activity.Experimental gerontology 03/2012; 47(6):417-24. · 3.34 Impact Factor -
Chapter: Eccentric Exercise, Muscle Damage and Oxidative Stress
02/2012; , ISBN: 978-953-51-0005-8 -
Article: The relationship between motor proficiency and pedometer-determined physical activity in young children.
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ABSTRACT: The aim of this study was to examine the relationship between motor proficiency and pedometer-determined physical activity in 5-6 year-old children. Participants (n = 232) were randomly recruited and assessed from 30 kindergartens in Northern Greece. Two trained researchers administered the measurements for the assessment of children's motor proficiency by using the BOTMP-SF. Physical activity was assessed by OMRON pedometers. Significant relationships between BOTMP-SF standard score and steps (S), aerobic walking time (AWT) and aerobic steps (AS), (p < .05) were found. When motor proficiency was divided into quartiles to assess the distribution of the relationship between motor proficiency and pedometer-derived variables, significant associations were found for AWT, S and AS (p < .001). Young children with high levels of motor proficiency were more active in contrast to their peers with lower motor proficiency. The findings add to the growing body of literature that considers motor skills/abilities as important elements of physical activity participation. (Abbreviations: S-steps per day; AS-aerobic steps per day; AWT-aerobic walking time (minutes·day(-1)); BOTMP-SF-Bruininks-Oseretsky Test of Motor Proficiency-Short Form (standard score)).Pediatric exercise science 02/2012; 24(1):34-44. · 1.71 Impact Factor -
Article: Elite premenarcheal rhythmic gymnasts demonstrate energy and dietary intake deficiencies during periods of intense training.
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ABSTRACT: This study determined dietary intake and energy balance of elite premenarcheal rhythmic gymnasts during their preseason training. Forty rhythmic gymnasts and 40 sedentary age-matched females (10-12 yrs) participated in the study. Anthropometric profile and skeletal ages were determined. Dietary intake and physical activity were assessed to estimate daily energy intake, daily energy expenditure, and resting metabolic rate. Groups demonstrated comparable height, bone age, pubertal development, resting metabolic rate. Gymnasts had lower body mass, BMI, body fat than age-matched controls. Although groups demonstrated comparable daily energy intake, gymnasts exhibited a higher daily energy expenditure resulting in a daily energy deficit. Gymnasts also had higher carbohydrate intake but lower fat and calcium intake. Both groups were below the recommended dietary allowances for fiber, water, calcium, phosphorus and vitamin intake. Gymnasts may need to raise their daily energy intake to avoid the energy deficit during periods of intense training.Pediatric exercise science 11/2011; 23(4):560-72. · 1.71 Impact Factor -
Article: Age-dependent changes in 8-oxoguanine-DNA glycosylase activity are modulated by adaptive responses to physical exercise in human skeletal muscle.
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ABSTRACT: 8-Oxo-7,8-dihydroguanine (8-oxoG) accumulates in the genome over time and is believed to contribute to the development of aging characteristics of skeletal muscle and various aging-related diseases. Here, we show a significantly increased level of intrahelical 8-oxoG and 8-oxoguanine-DNA glycosylase (OGG1) expression in aged human skeletal muscle compared to that of young individuals. In response to exercise, the 8-oxoG level was lastingly elevated in sedentary young and old subjects, but returned rapidly to preexercise levels in the DNA of physically active individuals independent of age. 8-OxoG levels in DNA were inversely correlated with the abundance of acetylated OGG1 (Ac-OGG1), but not with total OGG1, apurinic/apyrimidinic endonuclease 1 (APE1), or Ac-APE1. The actual Ac-OGG1 level was linked to exercise-induced oxidative stress, as shown by changes in lipid peroxide levels and expression of Cu,Zn-SOD, Mn-SOD, and SIRT3, as well as the balance between acetyltransferase p300/CBP and deacetylase SIRT1, but not SIRT6 expression. Together these data suggest that that acetylated form of OGG1, and not OGG1 itself, correlates inversely with the 8-oxoG level in the DNA of human skeletal muscle, and the Ac-OGG1 level is dependent on adaptive cellular responses to physical activity, but is age independent.Free radical biology & medicine 07/2011; 51(2):417-23. · 5.42 Impact Factor -
Article: No effect of antioxidant supplementation on muscle performance and blood redox status adaptations to eccentric training.
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ABSTRACT: It was recently reported that antioxidant supplementation decreases training efficiency and prevents cellular adaptations to chronic exercise. This study aimed to investigate the effects of vitamin C and vitamin E supplementation on muscle performance, blood and muscle redox status biomarkers, and hemolysis in trained and untrained men after acute and chronic exercise. A specific type of exercise was applied (eccentric) to produce long-lasting and extensive changes in redox status biomarkers and to examine more easily the potential effects of antioxidant supplementation. In a double-blinded fashion, men received either a daily oral supplement of vitamin C and vitamin E (n = 14) or placebo (n = 14) for 11 wk (started 4 wk before the pretraining exercise testing and continued until the posttraining exercise testing). After baseline testing, the subjects performed an eccentric exercise session 2 times/wk for 4 wk. Before and after the chronic eccentric exercise, the subjects underwent one session of acute eccentric exercise, physiologic measurements were performed, and blood samples and muscle biopsy samples (from 4 men) were collected. The results failed to support any effect of antioxidant supplementation. Eccentric exercise similarly modified muscle damage and performance, blood redox status biomarkers, and hemolysis in both the supplemented and nonsupplemented groups. This occurred despite the fact that eccentric exercise induced marked changes in muscle damage and performance and in redox status after exercise. The complete lack of any effect on the physiologic and biochemical outcome measures used raises questions about the validity of using oral antioxidant supplementation as a redox modulator of muscle and redox status in healthy humans.American Journal of Clinical Nutrition 06/2011; 93(6):1373-83. · 6.67 Impact Factor -
Article: A weekly bout of eccentric exercise is sufficient to induce health-promoting effects.
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ABSTRACT: The effects of chronic eccentric-only versus concentric-only exercise on muscle physiology and blood biochemistry were investigated. Twenty women performed on an isokinetic dynamometer a concentric (n = 10;mean ± SEM: age = 21.0 ± 0.4 yr, body fat = 22.0% ± 0.9%) or an eccentric (n = 10, age = 20.0 ± 0.3 yr, body fat = 23.2% ± 0.7%) exercise session using the knee extensors of both lower limbs once a week for eight subsequent weeks. Muscle function (isometric, concentric, and eccentric peak torque, range of movement, and soreness) was evaluated before, immediately after, and 48 h postexercise in each one of the eight training weeks. Body fat, resting energy expenditure (REE), lipid, and carbohydrate oxidation rate as well as blood chemistry measurements (lipid, lipoprotein and apolipoprotein profile, glucose, insulin, glycosylated hemoglobin, and creatine kinase) were examined before and 48 h postexercise at the first and eighth week of training. Acute eccentric exercise increased REE and fat oxidation at week 1 (12.7% and 12.9%, respectively) and at week 8 (0.7% and 2.8%, respectively). Chronic eccentric exercise increased resting REE and fat oxidation at week 8 compared with week 1 (5.0% and 9.9%, respectively). Acute eccentric exercise improved blood lipid profile at week 1 and week 8. Chronic eccentric exercise improved resting blood lipid profile at week 8. Acute eccentric exercise increased insulin resistance at week 1 but not at week 8. Chronic eccentric exercise decreased resting insulin resistance at week 8. It is reported for the first time that only 30 min of eccentric exercise per week for 8 wk was sufficient to improve health risk factors.Medicine and science in sports and exercise 01/2011; 43(1):64-73. · 3.71 Impact Factor -
Article: Physiological and performance adaptations of elite Greco-Roman wrestlers during a one-day tournament.
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ABSTRACT: The aim of this study was to determine the effects of a simulated one-day Greco-Roman wrestling tournament on selected performance and inflammatory status indices. Twelve competitive wrestlers (22.1 ± 1.3 years) completed five matches according to the official Olympic wrestling tournament regulations following a ~6% weight loss. Performance measurements, muscle damage assessment, and blood sampling were performed before and following each match. Performance and inflammatory markers were not affected by weight loss. Mean wrestling heart rate reached ~85% of maximal and lactate concentration exceeded 17 mM. Fatigue rating demonstrated a progressive rise (P < 0.05) throughout the tournament, peaking in match 4. Performance demonstrated a progressive deterioration (P < 0.05) throughout the tournament, especially in the last two matches (P < 0.05), with upper-body measures exhibiting a greater decline (P < 0.05) and remaining below baseline (P < 0.05) until the end of the tournament. Muscle damage markers increased during the course of the tournament with upper limbs affected more. Creatine kinase activity, CRP levels, IL-6 concentration, and leukocyte counts increased (P < 0.05) progressively throughout the tournament, peaking in the last two matches. Cortisol, epinephrine and norepinephrine increased (P < 0.05) after each match, but testosterone declined (P < 0.05) progressively, reaching a nadir before the last match. This inflammatory response was accompanied by a marked increase (p < 0.05) in lipid peroxidation, protein oxidation, and antioxidant status markers indicating the development of oxidative stress. These results suggest that a one-day wrestling tournament may induce significant physiological demands on wrestlers that may adversely affect their performance and inflammatory status especially during the later stages of the tournament.Arbeitsphysiologie 12/2010; 111(7):1421-36. · 2.15 Impact Factor -
Article: Time of sampling is crucial for measurement of cell-free plasma DNA following acute aseptic inflammation induced by exercise.
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ABSTRACT: To determine the time-course changes of cell-free plasma DNA (cfDNA) following heavy exercise. cfDNA concentration, C-reactive protein levels (hs-CRP), uric acid concentration (UA), creatine kinase activity (CK) were measured before and post-exercise (immediately post, 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 8h, 10h, 24h). cfDNA increased (15-fold) 30-min post-exercise and normalized thereafter. hs-CRP increased (56%, p<0.001) 1h post-exercise, remained elevated throughout recovery (52-142%, p<0.0001), and peaked (200% rise, p<0.0001) at 24h post-exercise. UA and CK increased (p<0.05), immediately post-exercise, remained elevated throughout recovery (p<0.0001), and peaked (p<0.0001) at 24h of post-exercise recovery. cfDNA sampling timing is crucial and a potential source of error following aseptic inflammation.Clinical biochemistry 11/2010; 43(16-17):1368-70. · 2.02 Impact Factor -
Article: Time course of changes in performance and inflammatory responses after acute plyometric exercise.
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ABSTRACT: The objectives of the present investigation were to study the inflammatory and performance responses after an acute bout of intense plyometric exercise during a prolonged recovery period. Participants were randomly assigned to either an experimental group (P, n = 12) that performed intense plyometric exercises or a control group (C, n = 12) that rested. The delayed onset of muscle soreness (DOMS), knee range of motion (KROM), creatine kinase (CK) and lactate dehydrogenase (LDH) activities, white blood cell count, C reactive protein (CRP), uric acid (UA), cortisol, testosterone, IL-6, IL-1b strength (isometric and isokinetic), and countermovement (CMJ) and static (SJ) jumping performance were measured at rest, immediately postexercise and at 24, 48, 72, 96, and 120 hours of recovery. Lactate was measured at rest and postexercise. Strength remained unchanged throughout recovery, but CMJ and SJ declined (p < 0.05) by 8-20%. P induced a marked rise in DOMS, CK, and LDH (peaked 24-48 hours postexercise) and a KROM decline. An acute-phase inflammatory response consisting of leukocytosis (postexercise and at 24 hours), an IL-6, IL-1b, CRP, and cortisol elevation (during the first 24 hours of recovery) and a delayed increase of UA (peaked at 48 hours) and testosterone (peaked at 72 hours) was observed in P. The results of this investigation indicate that performing an acute bout of intense plyometric exercise may induce a short-term muscle damage and marked but transient inflammatory responses. Jumping performance seems to deteriorate for as long as 72 hours postexercise, whereas strength appears to remain unchanged. The acute-phase inflammatory response after a plyometric exercise protocol appears to follow the same pattern as in other exercise models. These results clearly indicate the need of sufficient recovery between successive plyometric exercise training sessions.The Journal of Strength and Conditioning Research 04/2010; 24(5):1389-98. · 1.83 Impact Factor -
Article: Effects of L-carnitine on oxidative stress responses in patients with renal disease.
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ABSTRACT: Hemodialyzed patients demonstrate elevated oxidative stress and reduced functional status. Exercise induces health benefits, but acute exertion up-regulates oxidative stress responses in patients undergoing hemodialysis. Therefore, the aim of the present study was to examine the effect of L-carnitine supplementation on i) exercise performance and ii) blood redox status both at rest and after exercise. Twelve hemodialysis patients received either L-carnitine (20 mg kg(-1) i.v.) or placebo in a double-blind, placebo-controlled, counterbalanced, and crossover design for 8 wk. Participants performed an exercise test to exhaustion before and after supplementation. During the test, V˙O2, respiratory quotient, heart rate, and time to exhaustion were monitored. Blood samples, collected before and after exercise, were analyzed for lactate, malondialdehyde, protein carbonyls, reduced and oxidized glutathione, antioxidant capacity, catalase, and glutathione peroxidase activity. Blood carnitine increased by L-carnitine supplementation proportionately at rest and after exercise. L-carnitine supplementation increased time to fatigue (22%) and decreased postexercise lactate (37%), submaximal heart rate, and respiratory quotient but did not affect V˙O2peak. L-carnitine supplementation increased reduced/oxidized glutathione (2.7-fold at rest, 4-fold postexercise) and glutathione peroxidase activity (4.5% at rest, 10% postexercise) and decreased malondialdehyde (19% at rest and postexercise) and protein carbonyl (27% at rest, 40% postexercise) concentration. Data suggest that a 2-month L-carnitine supplementation may be effective in attenuating oxidative stress responses, enhancing antioxidant status, and improving performance of patients with end-stage renal disease.Medicine and science in sports and exercise 03/2010; 42(10):1809-18. · 3.71 Impact Factor -
Article: Intensity of resistance exercise determines adipokine and resting energy expenditure responses in overweight elderly individuals.
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ABSTRACT: To evaluate the time course of leptin, adiponectin, and resting energy expenditure (REE) responses in overweight elderly males after acute resistance exercise protocols of various intensity configurations. Forty inactive men (65-82 years) were randomly assigned to one of four groups (n = 10/group): control, low-intensity resistance exercise, moderate-intensity resistance exercise, and high-intensity resistance exercise. Exercise energy cost, REE, leptin, adiponectin, cortisol, insulin, lactate, glucose, nonesterified fatty acids (NEFAs), and glycerol were determined at baseline, immediately after exercise, and during a 72-h recovery period. Exercise energy cost was lower in high-intensity than in low-intensity and moderate-intensity groups (221.6 +/- 8.8 vs. 295.6 +/- 10.7 and 281.6 +/- 9.8 kcal, P < 0.001). Lactate, glucose, NEFAs, and glycerol concentrations increased (P < 0.001) after exercise and returned to baseline thereafter in all groups. REE increased (P < 0.001) in all groups at 12 h in an intensity-dependent manner (P < 0.05). REE reached baseline after 48 h in the low- and moderate-intensity groups and after 72 h in the high-intensity group. Cortisol peaked in all active groups after exercise (P < 0.001) and remained elevated (P < 0.001) for 12 h. After adjustment for plasma volume shifts, leptin remained unaltered. Adiponectin concentration increased after 12 h and remained elevated for 24 h only in the high-intensity group (P < 0.001). Resistance exercise does not alter circulating leptin concentration but does increase REE and adiponectin in an intensity-dependent manner for as long as 48 and 24 h, respectively, in overweight elderly individuals. It appears that resistance exercise may represent an effective approach for weight management and metabolic control in overweight elderly individuals.Diabetes care 09/2009; 32(12):2161-7. · 8.09 Impact Factor -
Article: Time-course of changes in inflammatory and performance responses following a soccer game.
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ABSTRACT: : To study the effects of a single soccer game on indices of performance, muscle damage, and inflammation during a 6-day recovery period. : Participants were assigned to either an experimental group (E, played in the game; n = 14) or a control group (C, did not participate in the game; n = 10). : Data were collected on a soccer field and at the Physical Education and Sports Science laboratory of the Democritus University of Thrace before and after the soccer game. : Twenty-four elite male soccer players (age, 20.1 +/- 0.8 years; height, 1.78 +/- 0.08 m; weight, 75.2 +/- 6.8 kg). : Muscle strength, vertical jumping, speed, DOMS, muscle swelling, leukocyte count, creatine kinase (CK), lactate dehydrogenase (LDH), C-reactive protein (CRP), cortisol, testosterone, cytokines IL-6 and IL-1b, thioburbituric acid-reactive substances (TBARS), protein carbnyls (PC), and uric acid (UA). : Performance deteriorated 1 to 4 days post-game. An acute-phase inflammatory response consisted of a post-game peak of leukocyte count, cytokines, and cortisol, a 24-hour peak of CRP, TBARS, and DOMS, a 48-hour peak of CK, LDH, and PC, and a 72-hour peak of uric acid. : A single soccer game induces short-term muscle damage and marked but transient inflammatory responses. Anaerobic performance seems to deteriorate for as long as 72-hour post-game. The acute phase inflammatory response in soccer appears to follow the same pattern as in other forms of exercise. These results clearly indicate the need of sufficient recovery for elite soccer players after a game.Clinical journal of sport medicine: official journal of the Canadian Academy of Sport Medicine 10/2008; 18(5):423-31. · 1.50 Impact Factor -
Article: Acute exercise may exacerbate oxidative stress response in hemodialysis patients.
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ABSTRACT: Hemodialyzed patients (HD) demonstrate elevated oxidative stress (OXS) levels. Exercise effects on OXS response and antioxidant status of HD was investigated in the present study. Twelve HD and 12 healthy controls (HC) performed a graded exercise protocol. Blood samples, collected prior to and following exercise, were analyzed for lactate, thiobarbituric acid-reactive substances (TBARS), protein carbonyls (PC), reduced (GSH) and oxidized glutathione (GSSG), total antioxidant capacity (TAC), catalase, and glutathione peroxidase (GPX) activity. HC demonstrated higher time-to-exhaustion (41%), lactate (41%) and VO2 peak (55%) levels. At rest, HD exhibited higher TBARS, PC, and catalase activity values and lower GSH, GSH/GSSG, TAC, and GPX levels. Although exercise elicited a marked change of OXS markers in both groups, these changes were more pronounced (p < 0.05) in HD patients. After adjusting for VO2 peak, differences between groups disappeared. VO2 peak was highly correlated with GSH/GSSG, TBARS, TAC and PC at rest and after exercise. These results imply that HD demonstrate higher OXS levels and a lower antioxidant status than HC at rest and following exercise. Acute exercise appears to exacerbate OXS response in hemodialyzed patients probably due to diminished antioxidant defense. However, aerobic capacity level seems to be related to OXS responses in this population.Nephron Clinical Practice 06/2008; 109(2):c55-64. · 2.04 Impact Factor -
Article: Oxidative stress biomarkers responses to physical overtraining: implications for diagnosis.
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ABSTRACT: Overtraining syndrome is characterized by declining performance and transient inflammation following periods of severe training with major health implications for the athletes. Currently, there is no single diagnostic marker for overtraining. The present investigation examined the responses of oxidative stress biomarkers to a resistance training protocol of progressively increased and decreased volume/intensity. Twelve males (21.3+/-2.3 years) participated in a 12-week resistance training consisting of five 3-week periods (T1, 2 tones/week; T2, 8 tones/week; T3, 14 tones/week; T4, 2 tones/week), followed by a 3-week period of complete rest. Blood/urine samples were collected at baseline and 96 h following the last training session of each period. Performance (strength, power, jumping ability) increased after T2 and declined thereafter, indicating an overtraining response. Overtraining (T3) induced sustained leukocytosis, an increase of urinary isoprostanes (7-fold), TBARS (56%), protein carbonyls (73%), catalase (96%), glutathione peroxidase, and oxidized glutathione (GSSG) (25%) and a decline of reduced glutathione (GSH) (31%), GSH/GSSG (56%), and total antioxidant capacity. Isoprostanes and GSH/GSSG were highly (r=0.764-0.911) correlated with performance drop and training volume increase. In conclusion, overtraining induces a marked response of oxidative stress biomarkers which, in some cases, was proportional to training load, suggesting that they may serve as a tool for overtraining diagnosis.Free Radical Biology and Medicine 10/2007; 43(6):901-10. · 5.42 Impact Factor -
Article: Sampling time is crucial for measurement of aerobic exercise-induced oxidative stress.
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ABSTRACT: To thoroughly investigate the time-course changes of several commonly used markers of oxidative stress by performing serial measurements during a 24-h period after an acute bout of strenuous cardiovascular exercise. Eleven untrained men performed two trials. In the experimental trial, the subjects exercised for 45 min at 70-75% VO2max and then at 90% VO2max to exhaustion on a treadmill; in the control trial, the subjects remained at rest. Blood samples were drawn before and after exercise (immediately after exercise and at 0.5, 1, 2, 3, 4, 5, 6, 8, 10, and 24 h). Reduced glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG, thiobarbituric acid-reactive substances (TBARS), protein carbonyls, catalase activity, and total antioxidant capacity (TAC) were determined. The time to lowest concentration after exercise was 1.7 +/- 0.7 h (mean +/- SD) for GSH/GSSG, and the time to highest concentration after exercise was 1.2 +/- 0.6 h for TBARS, 4.4 +/- 0.5 h for protein carbonyls, 0.5 +/- 0.4h for catalase, and 2.2 +/- 0.9 h for TAC. The greatest change after exercise was -74 +/- 9% for GSH/GSSG, 129 +/- 29% for TBARS, 135 +/- 53% for protein carbonyls, 51 +/- 16% for catalase, and 24 +/- 10% for TAC. There is no best time point applying to all markers for collecting blood samples after aerobic exercise. The optimum postexercise time points for blood collection in untrained individuals are immediately after exercise for catalase, 1 h for TBARS, 2 h for TAC, GSH, and GSSG, and 4 h after exercise for protein carbonyls.Medicine & Science in Sports & Exercise 08/2007; 39(7):1107-13. · 4.43 Impact Factor
Top co-authors
Top Journals
Institutions
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2007–2013
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University of Thessaly
- • Τμήμα Επιστήμης Φυσικής Αγωγής και Αθλητισμού
- • Βιοχημείας και Βιοτεχνολογίας
Vólos, Thessalia, Greece
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2011
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Center for Research and Technology, Thessaly
Vólos, Thessalia, Greece
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2004–2011
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Democritus University of Thrace
Xánthi, Anatoliki Makedonia kai Thraki, Greece
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1997
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University of North Carolina at Greensboro
- Department of Exercise and Sport Science
Greensboro, NC, USA
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