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T Fuentes,
J G Ponce-González,
D Morales-Alamo,
R de Torres-Peralta,
A Santana,
P De Pablos-Velasco, H Olmedillas,
A Guadalupe-Grau,
L Rodríguez-García,
J A Serrano-Sanchez,
B Guerra,
J A L Calbet
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ABSTRACT: To determine if the muscle signalling response to a 30 s all-out sprint exercise is modulated by the exercise mode and the endocrine response, 27 healthy volunteers were divided in 2 groups that performed isokinetic (10 men and 5 women) and isoinertial (7 men and 5 women) Wingate tests. Blood samples and vastus lateralis muscle biopsies were taken before, immediately after, 30 and 120 min after the sprints. Groups were comparable in age, height, body weight, percentage of body fat, peak power per kg of lower extremities lean mass (Pmax) and muscle fibre types. However, the isoinertial group achieved a 25% greater mean power (Pmean). Sprint exercise elicited marked increases in the musculus vastus lateralis AMPKα, ACCβ, STAT3, STAT5 and ERK1/2 phosphorylation (all P<0.05). The AMPKα, STAT3, and ERK1/2 phosphorylation responses were more marked after the isoinertial than isokinetic test (interaction: P<0.01). The differences in muscle signalling could not be accounted for by differences in Pmax, although Pmean could explain part of the difference in AMPKα phosphorylation. The leptin, insulin, glucose, GH, IL-6, and lactate response were similar in both groups. In conclusion, the muscle signalling response to sprint exercise differs between isoinertial and isokinetic sprints.
International Journal of Sports Medicine 11/2012; · 2.43 Impact Factor
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ABSTRACT: Endurance exercise induces SUPPRESSOR of CYTOKINE SIGNALING 3 (SOCS3) mRNA expression in rodent skeletal muscle and endurance training overimposed on strength training blunts the hypertrophic response to strength training by an unknown mechanism. The aim of this study was to determine the effects of a concurrent strength and endurance training on fat mass, serum leptin concentration, muscle morphology, and muscle vastus lateralis leptin receptors (OB-Rb) and SOCS3 protein expression. 16 healthy young men were assigned to a control (C; n=7), and to a 12-week weightlifting (3 sessions/week)+endurance training program (T; n=9) group. Training enhanced maximal dynamic strength in lower and upper body exercises (18-54%), reduced fat mass by 1.8 kg and serum leptin concentration per kg of fat mass, and elicited muscle hypertrophy of type 2 (+18.5%, P<0.05) but not of type 1 muscle fibres (+4.6%, P=NS). No significant changes were observed in either OB-Rb or SOCS3 protein expression with training. In conclusion, concurrent strength and endurance training reduces fat mass and serum leptin and the ratio leptin/fat mass without significant effects on vastus lateralis OB-Rb protein expression. Training does not increase the basal expression of SOCS3 protein in humans.
International Journal of Sports Medicine 05/2011; 32(5):319-26. · 2.43 Impact Factor
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ABSTRACT: To assess if exercise before puberty affects bone mineral content (BMC) and bone mineral density (BMD) we determined BMC and BMD in the dominant arm (DA) and non-dominant arm (NDA), lumbar spine and femoral neck in 25 tennis players (TP), 21 soccer players (SP) and 22 physically active controls (CG). All of them were under 12 years of age and prepubertal. In TP the DA was heavier than the NDA (7.5+/-0.8%), due to a greater lean mass (10.2+/-1.2%) and BMC (16.3+/-2.2%). The increased BMC is due to a greater DA bone area (11.1+/-1.9%) and BMD (4.1+/-0.7%). BMC inter-arm asymmetry was 50-75% of that previously observed in professional TP. Inter-arm asymmetry in lean mass, BMC, BMD and bone area was significantly higher in TP than in SP and CG. Lumbar spine BMC and BMD were similar across groups. TP and CG had similar femoral neck BMDs, whilst SP had higher femoral neck BMD than TP. In conclusion, tennis participation before puberty is associated with increased lean mass and bone mass, due to an enhanced bone size and areal BMD in the playing arm.
International Journal of Sports Medicine 03/2010; 31(6):416-20. · 2.43 Impact Factor
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Journal of Applied Physiology 09/2009; 107(2):637. · 3.75 Impact Factor
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ABSTRACT: The effects of professional tennis participation on dominant and non-dominant upper extremity muscle volumes, and on fiber types of triceps brachii (lateral head) and vastus lateralis muscles were assessed in 15 professional tennis players. Magnetic resonance imaging (MRI, n=8) examination and dual-energy x-ray absorptiometry (DXA, n=7) were used to assess muscle volumes and lean body mass. Muscle fiber-type distribution assessed by biopsy sampling was similar in both triceps brachii (2/3 were type 2 and 1/3 type 1 fibers). The VL was composed of 1/3 of type 2 and 2/3 of type 1 fibers. The dominant had 12-15% higher lean mass (DXA/MRI) than the non-dominant (P<0.05). Type 1, 2a and 2x muscle fibers of the dominant were hypertrophied compared with the non-dominant by 20%, 22% and 34% (all P<0.01), respectively. The deltoid, triceps brachii, arm flexors and forearm superficial flexor muscles of the dominant were hypertrophied (MRI) compared with the non-dominant by 11-15%. These muscles represented a similar fraction of the whole muscle volume in both upper extremities. Dominant muscle volume was correlated with 1RM on the one-arm cable triceps pushdown exercise (r=0.84, P<0.05). Peak power during vertical jump correlated with VL muscle fibers's cross-sectional area (r=0.82-0.95, P<0.05).
Scandinavian Journal of Medicine and Science in Sports 07/2009; 20(3):524-34. · 2.87 Impact Factor
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ABSTRACT: We compared 35 prepubertal girls, 9 artistic gymnasts and 13 rhythmic gymnasts with 13 nonphysically active controls to study the effect of gymnastics on bone and muscle mass. Lean mass, bone mineral content and areal density were measured by dual energy X-ray absorptiometry, and physical fitness was also assessed. The artistic gymnasts showed a delay in pubertal development compared to the other groups (p<0.05). The artistic gymnasts had a 16 and 17 % higher aerobic power and anaerobic capacity, while the rhythmic group had a 14 % higher anaerobic capacity than the controls, respectively (all p<0.05). The artistic gymnasts had higher lean mass (p<0.05) in the whole body and the extremities than both the rhythmic gymnasts and the controls. Body fat mass was 87.5 and 61.5 % higher in the controls than in the artistic and the rhythmic gymnasts (p<0.05). The upper extremity BMD was higher (p<0.05) in the artistic group compared to the other groups. Lean mass strongly correlated with bone mineral content (r=0.84, p<0.001), and multiple regression analysis showed that total lean mass explained 64 % of the variability in whole body bone mineral content, but only 20 % in whole body bone mineral density. Therefore, recreational artistic gymnastic participation is associated with delayed pubertal development, enhanced physical fitness, muscle mass, and bone density in prepubertal girls, eliciting a higher osteogenic stimulus than rhythmic gymnastic.
International Journal of Sports Medicine 05/2007; 28(5):386-93. · 2.43 Impact Factor
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Osteoporosis International. 22:354-355.
