Marina M.,INEFC Barcelona |
Jemni M.,University of Greenwich
Journal of Strength and Conditioning Research | Year: 2014
Marina, M and Jemni, M. Plyometric training performance in elite-oriented prepubertal female gymnasts. J Strength Cond Res 28(4): 1015-1025, 2014-We studied the effectiveness of a combined strength and plyometric training program (experimental period) on jumping performance when compared with a training routine on apparatus (control period) over 2 successive gymnastics training seasons. Nine female elite-orientated gymnasts (around 30-hour training per week) were participated in the study. The study was based on a 20-month longitudinal design covering 2 training seasons separated by a competitive period and transition periods. Each season included 1 control and 1 experimental period (CtrlΔ1 + ExΔ1 and CtrlΔ2 + ExΔ2, respectively). Before and after each control and experimental period, we assessed plyometric performance by means of drop jumps (DJs) from 20, 40, 60, 80, and 100 cm. The jump performance variables considered were flight time (FT), contact time (CT), flight-contact ratio (FC), and estimated mechanical power (also called Bosco expression [BE]), all of which were expressed as raw data and normalized (expressed as a percentage) with respect to the recordings at the beginning of each period of analysis. Flight time was the only variable to increase not only during both experimental periods but also during both controls. Our results confirmed larger relative increments of all the variables (FT, CT, BE, and FC), except for CT at DJs of 80 and 100 cm, during the experimental periods than during their respective previous control periods. Despite the additive effect of growth, development, and maturation, the gymnasts were not able to maintain the DJ performance accomplished during ExΔ1, thereby confirming detraining during the competitive and transition periods. We conclude that a combination of heavy resistance training with high impact plyometric jumps is effective in prepubertal gymnasts, despite their initial high level of physical conditioning. © 2014 National Strength and Conditioning Association.
Torrado P.,INEFC Barcelona |
Cabib C.,Hospital Clinic |
Morales M.,Hospital Clinic |
Valls-Sole J.,Hospital Clinic |
Marina M.,INEFC Barcelona
International Journal of Sports Medicine | Year: 2015
Highly repetitive submaximal intermittent contractions of the forearm muscles during periods of 30-50 min partially explain why motorcycle races are so demanding for the neuromuscular system. This study investigated the contribution of central and peripheral mechanisms of fatigue on the exerted and contralateral extensor digitorum communis following an intermittent fatigue protocol (IFP) designed for motorcycle riders. 12 riders performed an IFP, which simulates the braking and throttle handle gesture. We examined the time course of recovery of maximal voluntary contraction (MVC), M-wave, motor evoked potential (MEP) to transcranial magnetic stimuli in relaxed and facilitated condition, and the cortical silent period (CSP) at time windows of 1, 3, 5, 10 and 20 min after the IFP. Whereas MVC, M-wave and MEP decreased, CSP lengthened significantly in the fatigued limb after completion of the IFP. Nevertheless, no differences were observed in the contralateral limb. All neurophysiological parameters reverted to baseline values in less than 20 min, while MVC remained lower in the exercised limb. No cross-over effects were observed in the contralateral non-exercised limb. Our results suggest that local factors are those mainly responsible for the incomplete MVC recovery after an intermittent muscle contraction protocol. © Georg Thieme Verlag KG Stuttgart New York.
Marina M.,INEFC Barcelona |
Torrado P.,INEFC Barcelona
Journal of Sports Sciences | Year: 2013
The objective of this study was to confirm whether gymnastics practice from a young age can induce greater vertical jump reliability. Fifty young female gymnasts (8.84 ± 0.62 years) and 42 females in the control group (8.58 ± 0.92 years) performed the following jump tests on a contact mat: squat jump, countermovement jump, countermovement jump with arm swing and drop jump from heights of 40 and 60 cm. The two testing sessions had three trials each and were separated by one week. A 2 (groups) × 2 (sessions) × 3 (trials) repeated measures analysis of variance (ANOVA) and a test-retest correlation analysis were used to study the reliability. There was no systematic source of error in either group for nonplyometric jumps such as squat jump, countermovement jump, and countermovement jump with arm swing. A significant group per trial interaction revealed a learning effect in gymnasts' drop jumps from 40 cm height. Additionally, the test-retest correlation analysis and the higher minimum detectable error suggest that the quick drop jump technique was not fully consolidated in either group. At an introductory level of gymnastics and between the ages of 8-10 years, the condition of being a gymnast did not lead to conclusively higher reliability, aside from better overall vertical jump performance. © 2013 Taylor & Francis.
Marina M.,INEFC Barcelona |
Rodriguez F.A.,INEFC Barcelona
Biology of Sport | Year: 2014
The objective of this study was to investigate the physiological indices of competitive routines in women's artistic gymnastics by characterizing post-exercise heart rate (HR), oxygen uptake (VO2) and peak blood lactate concentration (Lmax) in a group of eight young elite-oriented female gymnasts. HR was continuously monitored with Polar RS400 monitors during the test event simulating a competition environment. Within 5 s of the end of each routine, the breath-by-breath gas analyser mask was placed on the face to record VO2. VO2max was calculated by the backward extrapolation method of the VO2 recovery curve. Lmax was obtained during recovery (min 1, 3, 5, 7 and 10) subsequent to each event. One week later, HR, VO2 and Lmax were measured during an incremental continuous treadmill test. The treadmill test was confirmed as the assessment with the highest physiological demand. The gymnasts reached their highest values of HR (183-199 beats · min-1), VO 2/Bm (33-44 ml · kg-1 · min-1) and Lmax (7-9 mmol · l-1) in the floor and uneven bars exercises. The vault was the event with the lowest HR (154-166 beats · min-1) and Lmax (2.4-2.6 mmol · l -1), and the balance beam had the lowest VO2 (27-35 ml · kg-1 · min-1). The mean relative peak intensities attained in the different events, which ranged from 65 to 85% of the individual VO2max and HRmax recorded in the laboratory, suggest that cardiorespiratory and metabolic demands are higher than previously indicated. The high percentage of VO2 measured, particularly after the floor event, suggests that aerobic power training should not be neglected in women's artistic gymnastics. Copyright © Biology of Sport 2014.
Marina M.,INEFC Barcelona |
Jemni M.,University of Greenwich |
Rodriguez F.,INEFC Barcelona
Journal of Sports Medicine and Physical Fitness | Year: 2013
Aim. The aim of this study was to establish a more precise jumping performance profile of elite gymnasts than that published in previous studies. Methods. Seventy-six elite male and female competitive gymnasts and 91 moderately active subjects volunteered for the study. The jumping tests performed on a contact mat were: squat jump (SJ) with progressive loads of 0%, 25%, 50%, 75% and 100% of body mass, counter-movement jump (CMJ), and counter-movement jump with arm swing (CMJA). The parameters used to assess the jumping performance were flight time (FT, ms), FT normalized to body mass (FTbm, ms/kg), estimated elastic component (EC) and arm participation (AP). In SJ, the overload with respect to body mass had a negative impact on reliability in all of the subgroups that were analysed. When overloads were above 50% of body mass in SJ, reliability was poor. Therefore, overloads should not be used with sedentary young females. Gymnasts carry out a large number of jumps from very young ages, which may explain their high jump reliability (ICC>0.91). Results. We used FT to estimate the F-v curve through SJ with overloads. The curves for male gymnasts and their controls were practically identical. However, when FT was normalized to body mass (FTbm), the F-v curve showed the advantage of female gymnasts in particular over their control group when overloads were above 50%. Larger, more significant (P<0.001) differences between gymnasts and their control groups were observed in CMJ and CMJA, with FTbminstead of FT. The combination of poor SJ and good CMJ performances explains why the EC was higher in gymnasts than in controls (+27%). Conclusion. The better AP of the gymnasts (+79%) may be due to better arm strength conditioning and segmental coordination. EC and AP can be considered a suitable complementary parameter of jumping performance in gymnasts.