Effetti dell'allenamento intermittente breve ad alta intensità e delle ripetute aerobiche sul Test Repeated Sprint Ability in giovani calciatori d'elite

The purpose of this study is to evaluate the effects of two different training methods: the repeated aerobic bouts and the short intermittent high intensity workout on the ability to carry out repeated sprint bouts RSA in a group of young soccer players and also to determine the impact of training on aerobic and neuromuscular performances. Twenty-Four (24) male soccer players have been assessed and trained, all of them partecipating regularly in the 2013-2014 season at the National Championship "Professional Development Phase" (Allievi Professionisti) with Cagliari Calcio SPA Football Club. Hereinafter the anthropometric characteristics of the sample tested: 16.33 ± 0.49 years, height 175 ± 6.3, 65.8 ± 6.8 weight. The 24 athletes were randomly included into two working groups: intermittent training group (HI. No. 12) and repeated aerobic exercise group (R. Aer. No. 12). Players underwent two separate sessions of evaluation tests. During the first session, in the morning, the players performed the vertical jump test (CMJ) with no counter movement (SJ). In the afternoon session the repeated sprint bouts were carried out (RSA). Finally the next day the athletes underwent the tests for the aerobic power (V.BILLAT). The results regarding the Aerobic Group (R. Aer.) were respectively SJ and CMJ at T0 36,95 ± 4,03cm; 37,44 ± 4,09cm; T1 to 37.99 ± 3.69 cm; 38.63 ± 3.96 cm; in the RSA tests we obtained the following T0 and T1 values respectively: 7.690 ± 0.12 s; 7,585 ± 0,11s; The Billat test instead highlighted the following values ± 1506 67,26m; 1596.6 ± 64,95m. The results regarding the Intermittent (HI) group were respectively SJ and CMJ at T0 36,69 ± 4,99cm; 37,98 ± 3,97cm; T1 to 38.15 ± 4.79 cm; 39.79 ± 3.78 cm; in the RSA tests we obtained the following T0 and T1 values respectively: 7.64 ± 0.11 s; 7.31 ± 0,11s; The Billat test instead highlighted the following values: 1537.3 ± 77,70m; 1627.1 ± 72,29m. The results indicate one or more variations of the investigated capacities between pre and post workout within the same group, and also suggest that by comparing the two methods, intermittent and repeated aerobic, the first of the two was more effective. The lack of a statistically significant difference on the capacity of aerobic performance evaluated through the Billat test suggests that both protocols have their validity in improving this component. While as regards the RSA test a statistically significant change was detected in favor of the intermittent protocol with respect to the repeated aerobic bouts. This variation was found through the reduction of the average execution time of the RSA test. Another result emerged from the statistical analysis is that both training protocols had no negative effects on neuromuscular skills assessed through the vertical jump test of the SJ and CMJ, this in agreement with what was found in previous studies such as Mc Millan (2005) and Ferrari (2007), in which training protocols for the aerobic performance of the player very similar to those used in this study were carried out. In conclusion the study indicated that the short high intensity intermittent method has proved more powerful than the Repeated Sprint Ability Test (RSA), which is indicated by most researchers as a key skill in football performance: we believe it respects mostly the kinematic analogies of the game, accelerations, decelerations and postural situations with minor variations of the bust concerning the various stages of the player's running (Paradisis GP. e coll. 2001) by an increased recruitment of the fast fibers in the rapid typical accelerations/decelerations of this sport. Furthermore we are inclined to hypothesize that this research reshapes the use of bioenergetic systems, already studied by (Dawson B. and coll. 1998), (to Ross, et al. 2001), it all along with the possibility of repeating the sprint at a high intensity with partial recoveries while maintaining a high quality and the considerable advantage, being soccer a situational sport, to help keep up a greater lucidity from a cognitive point of view and theoretically to select more logical and tactically effective choices

A 12-week vigorous exercise protocol in a healthy group of persons over 65: study of physical function by means of the senior fitness test

The aim of this study was to assess the effects of vigorous exercise on functional abilities bymeans of a Senior Fitness Test (SFT) in a group of elderly adults. Twenty healthy and inactive people performed vigorous exercise (VE: 12 men and 8 women, aged 69.6 ± 3.9 years). At the beginning of the study (T0) and after 3months (T1), each subject’s functional ability was tested formuscular strength, agility, cardiovascular fitness, flexibility, and balance.The VE was designed with continuous and interval exercise involving large muscle activities. Functional exercises were performed between 60% and 84% of heart rate reserve (HRR) for a duration of 65 minutes. Five out of the 6 SFTs performed were found significantly improved: Chair Stand (T0 12.4 ± 2.4, T1 13.5 ± 2.6, < 0.01), Arm Curl (T0 14.2 ± 3.6, T1 16.6 ± 3.6, < 0.01), 2 min step (T0 98.2 ± 15.7, T1 108.9 ± 16.2, < 0.01), Chair Sit-and-Reach (T0 −9.9 ± 7.7 cm, T1 1.7 ± 6.3 cm, < 0.01), and Back Scratch (T0 −15.8 ± 10.9 cm, T1 −8.4 ± 13.1 cm, < 0.01). Our results suggest that a high intensity protocol and functional exercises can improve functional mobility and muscle endurance in those over 65 years of age. SFTs are an effective method for assessing improvements in the functional capacity of elderly adults

Mean blood pressure assessment during post-exercise: Result from two different methods of calculation

At rest the proportion between systolic and diastolic periods of the cardiac cycle is about 1/3 and 2/3 respectively. Therefore, mean blood pressure (MBP) is usually calculated with a standard formula (SF) as follows: MBP = diastolic blood pressure (DBP) + 1/3 [systolic blood pressure (SBP) – DBP]. However, during exercise this proportion is lost because of tachycardia, which shortens diastole more than systole. We analysed the difference in MBP calculation between the SF and a corrected formula (CF) which takes into account changes in the diastolic and systolic periods caused by exercise-induced tachycardia. Our hypothesis was that the SF potentially induce a systematic error in MBP assessment during recovery after exercise. Ten healthy males underwent two exercise-recovery tests on a cycle-ergometer at mild-moderate and moderate-heavy workloads. Hemodynamics and MBP were monitored for 30 minutes after exercise bouts. The main result was that the SF on average underestimated MBP by –4.1 mmHg with respect to the CF. Moreover, in the period immediately after exercise, when sustained tachycardia occurred, the difference between SF and CF was large (in the order of -20-30 mmHg). Likewise, a systematic error in systemic vascular resistance assessment was present. It was concluded that the SF introduces a substantial error in MBP estimation in the period immediately following effort. This equation should not be used in this situation

Fatigue-Induced Balance Impairment in Young Soccer Players

Context: Although balance is generally recognized to be an important feature in ensuring good performance in soccer, its link with functional performance remains mostly unexplored, especially in young athletes. Objective: To investigate changes in balance induced by fatigue for unipedal and bipedal static stances in young soccer players. Design: Crossover study. Setting: Biomechanics laboratory and outdoor soccer field. Patients or Other Participants:   Twenty-one male soccer players (age = 14.5 ± 0.2 years, height = 164.5 ± 5.6 cm, mass = 56.8 ± 6.8 kg). Intervention(s): Static balance was assessed with postural-sway analysis in unipedal and bipedal upright stance before and after a fatigue protocol consisting of a repeated sprint ability (RSA) test (2 × 15-m shuttle sprint interspersed with 20 seconds of passive recovery, repeated 6 times). Main Outcome Measure(s): On the basis of the center of pressure (COP) time series acquired during the experimental tests, we measured sway area, COP path length, and COP maximum displacement and velocity in the anteroposterior and mediolateral directions. Results: Fatigue increased all sway values in bipedal stance and all values except COP velocity in the mediolateral direction in unipedal stance. Fatigue index (calculated on the basis of RSA performance) was positively correlated with fatigue/rest sway ratio for COP path length and COP velocity in the anteroposterior and mediolateral directions for nondominant single-legged stance. Conclusions: Fatigued players exhibited reduced performance of the postural-control system. Participants with better performance in the RSA test appeared less affected by balance impairment, especially in single-legged stance

A 12-Week Vigorous Exercise Protocol in a Healthy Group of Persons over 65: Study of Physical Function by means of the Senior Fitness Test

The aim of this study was to assess the effects of vigorous exercise on functional abilities by means of a Senior Fitness Test (SFT) in a group of elderly adults. Twenty healthy and inactive people performed vigorous exercise (VE: 12 men and 8 women, aged 69.6 ± 3.9 years). At the beginning of the study (T0) and after 3 months (T1), each subject’s functional ability was tested for muscular strength, agility, cardiovascular fitness, flexibility, and balance. The VE was designed with continuous and interval exercise involving large muscle activities. Functional exercises were performed between 60% and 84% of heart rate reserve (HRR) for a duration of 65 minutes. Five out of the 6 SFTs performed were found significantly improved: Chair Stand (T0 12.4 ± 2.4, T1 13.5 ± 2.6, p<0.01), Arm Curl (T0 14.2 ± 3.6, T1 16.6 ± 3.6, p<0.01), 2 min step (T0 98.2 ± 15.7, T1 108.9 ± 16.2, p<0.01), Chair Sit-and-Reach (T0 −9.9 ± 7.7 cm, T1 1.7 ± 6.3 cm, p<0.01), and Back Scratch (T0 −15.8 ± 10.9 cm, T1 −8.4 ± 13.1 cm, p<0.01). Our results suggest that a high intensity protocol and functional exercises can improve functional mobility and muscle endurance in those over 65 years of age. SFTs are an effective method for assessing improvements in the functional capacity of elderly adults

Mean Blood Pressure Assessment during Post-Exercise: Result from Two Different Methods of Calculation

At rest the proportion between systolic and diastolic periods of the cardiac cycle is about 1/3 and 2/3 respectively. Therefore, mean blood pressure (MBP) is usually calculated with a standard formula (SF) as follows: MBP = diastolic blood pressure (DBP) + 1/3 [systolic blood pressure (SBP) – DBP]. However, during exercise this proportion is lost because of tachycardia, which shortens diastole more than systole. We analysed the difference in MBP calculation between the SF and a corrected formula (CF) which takes into account changes in the diastolic and systolic periods caused by exercise-induced tachycardia. Our hypothesis was that the SF potentially induce a systematic error in MBP assessment during recovery after exercise. Ten healthy males underwent two exercise-recovery tests on a cycle-ergometer at mild-moderate and moderate-heavy workloads. Hemodynamics and MBP were monitored for 30 minutes after exercise bouts. The main result was that the SF on average underestimated MBP by –4.1 mmHg with respect to the CF. Moreover, in the period immediately after exercise, when sustained tachycardia occurred, the difference between SF and CF was large (in the order of -20-30 mmHg). Likewise, a systematic error in systemic vascular resistance assessment was present. It was concluded that the SF introduces a substantial error in MBP estimation in the period immediately following effort. This equation should not be used in this situation