Antonis Kambas

Strength training and detraining effects on muscular strength, anaerobic power, and mobility of inactive older men are intensity dependent

Background: Although strength training (ST) enhances physical function in the elderly, little is known about the effect of training intensity on training and detraining adaptations in musculoskeletal fitness. Objective: To determine the effect of exercise intensity on strength, anaerobic power, and mobility of older men subjected to a 24 week ST protocol followed by prolonged detraining. Methods: Fifty two healthy but inactive older men (mean (SD) age 71.2 (4.1) years) were assigned to a control (n  =  14), low intensity training (LIST; n  =  18; 55% 1RM), or high intensity training (HIST; n  =  20; 82% 1RM) group. They carried out a 24 week, whole body (10 exercises, two to three sets/exercise) ST programme followed by a 48 week detraining period. Upper and lower body strength, anaerobic power (Wingate testing), and mobility (timed up and go, walking, climbing stairs) were measured at baseline and immediately after training and during detraining. Results: Although low intensity training improved (p<0.05) strength (42–66%), anaerobic power (10%), and mobility (5–7%), high intensity training elicited greater (p<0.05) gains (63–91% in strength, 17–25% in anaerobic power, 9–14% in mobility). All training induced gains in the LIST group had been abolished after four to eight months of detraining, whereas in the HIST group strength and mobility gains were maintained throughout detraining. However, anaerobic power had returned to baseline levels after four months of detraining in both groups. Conclusions: Higher intensity training protocols induce greater gains in strength, anaerobic power, and whole body physical function of older men. Moreover, higher intensity training may maintain the gains for more prolonged periods after training ceases.

Reliability and validity of age band 1 of the Movement Assessment Battery for Children - Second Edition

The purpose of this study was to examine specific aspects of the reliability and validity of age band 1 of the Movement Assessment Battery for Children--Second Edition (MABC-2) (Henderson, Sugden, & Barnett, 2007) in Greek preschool children. One hundred and eighty-three children participated in the study; the children ranged in age from 36 to 64 months old (M = 50 months, SD = 9 months). Test-retest reliability of the MABC-2 was evaluated using intraclass correlation coefficient (ICC). Cronbachs alpha for the items of each motor domain was estimated to determine internal consistency. Confirmatory factor analysis was used to examine the factorial validity of the MABC-2 test. Correlation coefficients among individual item scores and the total score were also calculated to further examine validity. The ICC for all test items was good, except for the drawing trail task, which was moderate. Cronbachs alpha coefficient values were .51, .70 and .66 for manual dexterity, aiming and catching, and balance, respectively. In the confirmatory factor analysis, goodness-of-fit indices suggested a satisfactory fit of the data to the model. The correlation coefficients between each test item and the total score were moderate. The results suggest that the MABC-2 can be a reliable and valid tool for the assessment of movement difficulties among 3-5-year-old children.

Effect of Rhythmic Gymnastics on Volumetric Bone Mineral Density and Bone Geometry in Premenarcheal Female Athletes and Controls

CONTEXT AND OBJECTIVE Weight-bearing exercise during growth exerts positive effects on the skeleton. Our objective was to test the hypothesis that long-term elite rhythmic gymnastics exerts positive effects on volumetric bone mineral density and geometry and to determine whether exercise-induced bone adaptation is associated with increased periosteal bone formation or medullary contraction using tibial peripheral quantitative computed tomography and bone turnover markers. DESIGN AND SETTING We conducted a cross-sectional study at a tertiary center. SUBJECTS We studied 26 elite premenarcheal female rhythmic gymnasts (RG) and 23 female controls, aged 9-13 yr. MAIN OUTCOME MEASURES We measured bone age, volumetric bone mineral density, bone mineral content (BMC), cortical thickness, cortical and trabecular area, and polar stress strength index (SSIp) by peripheral quantitative computed tomography of the left tibia proximal to the distal metaphysis (trabecular) at 14, 38 (cortical), and 66% (muscle mass) from the distal end and bone turnover markers. RESULTS The two groups were comparable according to height and chronological and bone age. After weight adjustment, cortical BMC, area, and thickness at 38% were significantly higher in RG (P < 0.005-0.001). Periosteal circumference, SSIp, and muscle area were higher in RG (P < 0.01-0.001). Muscle area was significantly associated with cortical BMC, area, and SSIp, whereas years of training showed positive association with cortical BMC, area, and thickness independent of chronological age. CONCLUSIONS RG in premenarcheal girls may induce positive adaptations on the skeleton, especially in cortical bone. Increased duration of exercise is associated with a positive response of bone geometry.

Construct Validity of the Bruininks-Oseretsky Test of Motor Proficiency–Short Form for a Sample of Greek Preschool and Primary School Children

The construct validity of the short form of the Bruininks-Oseretsky Test of Motor Proficiency for the assessment of gross and fine motor skills was assessed in 377 nondisabled Greek preschool and primary school children (age range 5 yr. to 8:3 mo.) from urban areas of northern Greece. Analysis showed the three factors accounted for 54.1% of the total score variance, agreeing with the earlier findings. Moreover, the item scores had statistically significant relationships with the total short-form score, except for that of copying a circle with the preferred hand. This latter item was also the only one with a small effect size. Age confirmed a statistically significant effect on the scores of the half items of the test battery, also an earlier finding. This test seemed to be a valid test of motor proficiency in normal Greek preschool and primary school children.

How can a traditional Greek dances programme affect the motor proficiency of pre‐school children?

The purpose of this article is to investigate the effect of an introductory traditional Greek dances programme on the motor proficiency development of pre‐school‐age children. The sample of this research consisted of 66 students (36 boys and 30 girls) attending public kindergarten in Argolida prefecture (Greece), aged 4–6 years (X = 59.79 ± 6.40 months). For the assessment of motor proficiency the ‘Test for children 4–6 years of age’ (Motoriktest für vier‐bis sechsjährige Kinder, MOT 4–6, Zimmer & Volkamer, 1987 ) was used. The children of the experimental group (n = 28) attended the intervention programme for 20 weeks, participating in two sessions a week, while the children of the control group (n = 38) did not participate regularly in any organized physical activity programme. A two‐way ANOVA model for repeated measures was used for data analysis. From the results, while both groups displayed an improvement in their performance, the experimental group surpassed statistically significantly the control group in the post‐test. From the results it was observed that an introductory traditional Greek dances programme can notably improve children’s motor proficiency.

The microcycle of inflammation and performance changes after a basketball match

Abstract Basketball incorporates intense eccentric muscle activity that induces muscle microtrauma and an inflammatory response. This study investigated time-dependent inflammatory and performance responses during a weekly microcycle after a basketball match. Twenty elite-standard players underwent a trial that comprised a match followed by a 6-day simulated in-season microcycle. The trial was preceded by a control condition that did not have a match. Blood sampling and tests of maximal-intensity exercise performance and muscle damage occurred before each condition, immediately after the match and daily thereafter for 6 consecutive days. The match induced marked increases in heart rate, lactate, ammonia, glucose, non-esterified fatty acids and triglycerides. Performance deteriorated for 24–48 h after the match, whereas knee flexor and extensor soreness increased for 48 and 24 h post-match, respectively. Inflammatory (leukocytes, C-reactive protein, creatine kinase activity, adhesion molecules, cortisol, uric acid and cytokines) and oxidative stress (malondialdehyde, protein carbonyls, oxidised glutathione, antioxidant capacity, catalase and glutathione peroxidase) markers increased for ~24 h and subsided thereafter. Reduced glutathione declined for 24 h after exercise. These results suggest that a basketball match elicits moderate and relatively brief (~24–48 h) inflammatory responses, is associated with marked but short-lived performance deterioration, but is less stressful than other intermittent-type sports.

The time-frame of acute resistance exercise effects on football skill performance: The impact of exercise intensity

Abstract The purpose of this study was to determine the recovery rate of football skill performance following resistance exercise of moderate or high intensity. Ten elite football players participated in three different trials: control, low-intensity resistance exercise (4 sets, 8–10 repetitions/set, 65–70% 1 repetition maximum [1RM]) and high-intensity resistance exercise (4 sets, 4–6 repetitions/set, 85–90% 1RM) in a counterbalanced manner. In each experimental condition, participants were evaluated pre, post, and at 24, 48, 72 h post exercise time points. Football skill performance was assessed through the Loughborough Soccer Passing Test, long passing, dribbling, shooting and heading. Delayed onset muscle soreness, knee joint range of motion, and muscle strength (1RM) in squat were considered as muscle damage markers. Blood samples analysed for creatine kinase activity, C-reactive protein, and leukocyte count. Passing and shooting performance declined (P < 0.05) post-exercise following resistance exercise. Strength declined post-exercise following high-intensity resistance exercise. Both trials induced only a mild muscle damage and inflammatory response in an intensity-dependent manner. These results indicate that football skill performance is minimally affected by acute resistance exercise independent of intensity suggesting that elite players may be able to participate in a football practice or match after only 24 h following a strength training session.

A Microcycle of Inflammation Following a Team Handball Game

Abstract Chatzinikolaou, A, Christoforidis, C, Avloniti, A, Draganidis, D, Jamurtas, AZ, Stampoulis, T, Ermidis, G, Sovatzidis, A, Papassotiriou, I, Kambas, A, and Fatouros, IG. A microcycle of inflammation following a team handball game. J Strength Cond Res 28(7): 1981–1994, 2014—This study investigated the time-course of performance and inflammatory responses during a simulated 6-day in-season microcycle following a team handball (TH) game. Twenty-four handball players participated in a 1-week control trial and in an experimental trial (TH game participation followed by a 6-day training microcycle). Concentrations of lactate, glucose, glycerol, triglycerides, nonesterified fatty acids (NEFAs), and ammonia were measured pregame and postgame. Heart rate (HR) was monitored during the game. Performance (jumping, speed, agility, line-drill testing, and strength), muscle damage (knee range of motion [ROM], knee extensors/flexors delayed onset muscle soreness [DOMS], and creatine kinase activity [CK]), inflammatory (leukocyte count, C-reactive protein, interleukins 1&bgr; and 6 [IL-1&bgr; and IL-6], soluble vascular adhesion molecule 1 [sVCAM-1], p-selectin, uric acid, cortisol, and testosterone), and oxidative stress (malondialdehyde [MDA], protein carbonyls [PC], reduced [GSH] and oxidized glutathione [GSSG], total antioxidant capacity (TAC), catalase, glutathione peroxidase activity [GPX]) markers were determined pregame, postgame, and daily for 6 consecutive days postgame. The game induced a marked rise of HR (∼170 b·min−1), lactate (∼8-fold), glycerol (60%), NEFA (105%), and ammonia (∼62%). Performance deteriorated until 24 hours postgame. Knee ROM decreased (3–5%), whereas DOMS and CK increased (3- to 5-fold and 80–100%, respectively) 24 hours postgame. Leukocyte count, IL-1&bgr;, IL-6, cortisol, MDA, PC, and catalase increased only immediately postgame. C-reactive protein and uric acid increased at 24 hours; sVCAM-1, GSSG, and GPX peaked postgame and remained elevated for 24 hours. The GSH declined until 24 hours postgame. Results suggest that a TH game represents a strong metabolic challenge and induces a short-lived and modest inflammatory response that may affect performance for as long as 24 hours postgame.

The effect of leg kick on sprint front crawl swimming

Abstract The aim of this study was to examine the influence of leg kick on the pattern, the orientation and the propulsive forces produced by the hand, the efficiency of the arm stroke, the trunk inclination, the inter-arm coordination and the intra-cyclic horizontal velocity variation of the hip in sprint front crawl swimming. Nine female swimmers swam two maximal trials of 25 m front crawl, with and without leg kick. Four camcorders were used to record the underwater movements. Using the legs, the mean swimming velocity increased significantly. On the contrary, the velocity and the orientation of the hand, the magnitude and the direction of the propulsive forces, as well as the Froude efficiency of the arm stroke were not modified. The hip intra-cyclic horizontal velocity variation was also not changed, while the index of coordination decreased significantly. A significant decrease (13%) was also observed in the inclination of the trunk. Thus, the positive effect of leg kick on the swimming speed, besides the obvious direct generation of propulsive forces from the legs, could probably be attributed to the reduction of the body’s inclination, while the generation of the propulsive forces and the efficiency of the arm stroke seem not to be significantly affected.

Antioxidation improves in puberty in normal weight and obese boys, in positive association with exercise-stimulated growth hormone secretion

Background:Oxidative stress is associated with obesity while the evidence for the role of GH in pro- and antioxidation is inconclusive. This study investigates the relationships between growth hormone (GH), pro- and antioxidation in relation to obesity and puberty before and after an acute bout of exercise.Methods:In this case–control study, 76 healthy normal-weight and obese, prepubertal and pubertal boys underwent a blood sampling before and immediately after an aerobic exercise bout until exhaustion at 70% maximal oxygen consumption. Markers of prooxidation (thiobarbituric acid reactive substances (TBARS) and protein carbonyls (PCs)) and antioxidation (glutathione (GSH), oxidized glutathione disulfide (GSSG), GSH/GSSG ratio, glutathione peroxidase (GPX), catalase, and total antioxidant capacity (TAC)) and hormones (GH, insulin-like growth factor (IGF)-1, IGF-BP-3, luteinizing hormone, follicle-stimulating hormone, and testosterone) were measured.Results:Baseline and postexercise TBARS and PCs were greater, while baseline GSH, GSH/GSSG ratio, GPX, and TAC were lower in obese than that in normal-weight participants. In all participants, waist was the best negative and positive predictor for postexercise GPX and TBARS, respectively. Baseline TAC was greater in pubertal than that in pre-pubertal participants. In all participants, baseline GH was the best negative predictor for postexercise PCs. Significant positive linear correlation exists between the exercise-associated GH, and GSSG increases in pubertal normal-weight boys.Conclusions:Higher prooxidation and lower antioxidation were observed in obese boys, while antioxidation improves with puberty and postexercise, paralleling GH accentuated secretion.