Vincenzo Manzi

Dose-response relationship of autonomic nervous system responses to individualized training impulse in marathon runners.

In athletes, exercise training induces autonomic nervous system (ANS) adaptations that could be used to monitor training status. However, the relationship between training and ANS in athletes has been investigated without regard for individual training loads. We tested the hypothesis that in long-distance athletes, changes in ANS parameters are dose-response related to individual volume/intensity training load and could predict athletic performance. A spectral analysis of heart rate (HR), systolic arterial pressure variability, and baroreflex sensitivity by the sequences technique was investigated in eight recreational athletes during a 6-mo training period culminating with a marathon. Individualized training load responses were monitored by a modified training impulse (TRIMP(i)) method, which was determined in each athlete using the individual HR and lactate profiling determined during a treadmill test. Monthly TRIMP(i) steadily increased during the training period. All the ANS parameters were significantly and very highly correlated to the dose of exercise with a second-order regression model (r(2) ranged from 0.90 to 0.99; P < 0.001). Variance, high-frequency oscillations of HR variability (HRV), and baroreflex sensitivity resembled a bell-shaped curve with a minimum at the highest TRIMP(i), whereas low-frequency oscillations of HR and systolic arterial pressure variability and the low frequency (LF)-to-high frequency ratio resembled an U-shaped curve with a maximum at the highest TRIMP(i). The LF component of HRV assessed at the last recording session was significantly and inversely correlated to the time needed to complete the nearing marathon. These results suggest that in recreational athletes, ANS adaptations to exercise training are dose related on an individual basis, showing a progressive shift toward a sympathetic predominance, and that LF oscillations in HRV at peak training load could predict athletic achievement in this athlete population.

Effect of recovery mode on repeated sprint ability in young basketball players.

The aim of this study was to examine the effect of recovery mode on repeated sprint ability in young basketball players. Sixteen basketball players (age, 16.8 ± 1.2 years; height, 181.3 ± 5.7 cm; body mass, 73 ± 10 kg; VO2max, 59.5 ± 7.9 mL·kg−1·min−1) performed in random order over 2 separate occasions 2 repeated sprint ability protocols consisting of 10 × 30-m shuttle run sprints with 30 seconds of passive or active (running at 50% of maximal aerobic speed) recovery. Results showed that fatigue index (FI) during the active protocol was significantly greater than in the passive condition (5.05 ± 2.4, and 3.39 ± 2.3, respectively, p < 0.001). No significant association was found between VO2peak and FI and sprint total time (TT) in either repeated sprint protocols. Blood lactate concentration at 3 minutes post exercise was not significantly different between the 2 recovery conditions. The results of this study show that during repeated sprinting, passive recovery enabled better performance, reducing fatigue. Consequently, the use of passive recovery is advisable during competition in order to limit fatigue as a consequence of repeated high intensity exercise.

Relation between maximal aerobic power and the ability to repeat sprints in young basketball players.

The aim of this study was to examine the effects of maximal aerobic power (&OV0622;O2peak) level on the ability to repeat sprints (calculated as performance decrement and total sprinting time) in young basketball players. Subjects were 18 junior, well-trained basketball players (age, 16.8 ± 1.2 years; height, 181.3 ± 5.7 cm; body mass, 73 ± 10 kg; &OV0622;O2peak, 59.6 ± 6.9 ml·kg−1·min−1). Match analysis and time-motion analysis of competitive basketball games was used to devise a basketball-specific repeated-sprint ability protocol consisting of ten 15-m shuttle run sprints with 30 s of passive recovery. Pre, post, and post plus 3-minute blood lactate concentrations were 2.5 = 0.7, 13.6 ± 3.1, and 14.2 ± 3.5 mmol·L−1, respectively. The mean fatigue index (FI) value was 3.4 ± 2.3% (range, 1.1–9.1%). No significant correlations were found between &OV0622;O2peak and either FI or total sprint time. A negative correlation (r = −0.75, p = 0.01) was found between first-sprint time and FI. The results of this study showed that &OV0622;O2peak is not a predictor of repeated-sprint ability in young basketball players. The high blood lactate concentrations found at the end of the repeated-sprint ability protocol suggest its use for building lactate tolerance in conditioned basketball players.

Matched dose interval and continuous exercise training induce similar cardiorespiratory and metabolic adaptations in patients with heart failure

BACKGROUND The best format of exercise training in patients with chronic heart failure (CHF) is controversial. We tested the hypothesis that aerobic continuous training (ACT) and aerobic interval training (AIT) induce similar effects on functional capacity, central hemodynamics and metabolic profile in patients with postinfarction CHF provided that the training load is equated by an individually-tailored volume/intensity dose of exercise. METHODS Twenty patients with postinfarction CHF under optimal medical treatment were randomized to ACT or AIT for 12 weeks. Exercise training consisted in individualized loads prescribed according to the Training Impulses (TRIMPi) method, which was determined using the individual HR and lactate profiling obtained during a treadmill test at baseline. RESULTS Peak VO2 increased significantly by 22% with both ACT and AIT, without differences between the two training programs. Changes in anaerobic threshold and VE/VCO2 slope were not significantly different between ACT and AIT. Resting HR significantly decreased with both exercise modes. Resting cardiac output and stroke volume, left ventricular diastolic dimension and ejection fraction did not change from baseline with both exercise modes. Lipid profile and glucose metabolism were not substantially altered by ACT and AIT. CONCLUSIONS ACT and AIT both induce significant improvement in aerobic capacity in patients with postinfarction CHF, without significant differences between the two training modes, provided that patients are trained at the same, individually tailored, dose of exercise. The TRIMPi method might represent a step forward in the individualization of an aerobic training tailored to the patients clinical and functional status within cardiac rehabilitation programs.

Intermittent Endurance and Repeated Sprint Ability in Soccer Players

Chaouachi, A, Manzi, V, Wong, DP, Chaalali, A, Laurencelle, L, Chamari, K, and Castagna, C. Intermittent endurance and repeated sprint ability in soccer players. J Strength Cond Res 24(x): 000-000, 2010-The ability to perform high-intensity intermittent exercise (i.e., Yo-Yo Intermittent Recovery Test [Yo-Yo IR1]) and to repeat sprints with relatively short recovery times (i.e., 20- to 30-seconds, relatively short time interval [repeated sprint ability (RSA)]) has been shown to be relevant fitness variables in soccer. However, though they potentially share common features, it is not known whether these 2 abilities are associated. The aim of this study was to examine the relationships between Yo-Yo IR1 and RSA performances in elite soccer players. Twenty-three soccer players (age 19 ± 1 years, height 181 ± 5.7 cm, body mass 73.2 ± 4.1 kg, %body fat 11 ± 2.4) performed the Yo-Yo IR1 and a test for RSA (7 × 30 m with 25-second recovery). Results were 2,289 ± 409 m, 31.21 ± 1.13 seconds, and 4 ± 2.1% for Yo-Yo IR1, total sprint time, and sprint decrement, respectively. Yo-Yo IR1 showed a significant and moderate relationship with sprint decrement (r = −0.44, p = 0.04). Splitting the sample into Best and Worst Yo-Yo IR1 performers according to median score (2,320 m), the Best group showed lower RSA total time (30.69 ± 0.99 vs. 31.79 ± 1.06, p < 0.05) and speed decrement (2.90 ± 0.86 vs. 5.09 ± 2.42, p < 0.01) compared to the Worst group. Sprint-time deterioration over 30 m occurred earlier (from the second sprint on) in the Yo-YoWorst compared with in the Yo-YoBest group (from the fourth sprint on, p < 0.001). Intermittent high-intensity endurance is poorly associated with RSA performance (r2 = 0.19). Consequently, coaches and strength and conditioning professionals should consider both Yo-Yo IR1 and RSA in their testing batteries. A Yo-Yo IR1 performance ≥2,320 m could be considered as a reasonable indicator of physical fitness in elite soccer. Relatively short time interval test protocols similar to the present study should consist of at least 5 sprint bouts.

Effect of Training Intensity Distribution on Aerobic Fitness Variables in Elite Soccer Players: A Case Study

Castagna, C, Impellizzeri, FM, Chaouachi, A, Bordon, C, and Manzi, V. Effect of training intensity distribution on aerobic fitness variables in elite soccer players: A case study. J Strength Cond Res 25(1): 66-71, 2011-The aim of this article was to quantify the distribution of training intensities and its effect on aerobic fitness in professional elite soccer players. Fourteen professional soccer players were observed during the prechampionship training period (6 weeks). Treadmill running speed and heart rates (HRs) at 2 and 4 mmol·L−1 blood-lactate concentrations were assessed pre and posttraining. Training intensities were categorized using 3 HR zones: low intensity (HR 4 mmol·L−1). Analysis of the 504 individual training sessions showed that 73 ± 2.5, 19 ± 2.8, and 8 ± 1.4% of the total training time was spent at low, moderate, and high intensity, respectively (p < 0.001). Speed at 2 and 4 mmol·L−1 significantly improved posttraining (5 and 7%, respectively, p < 0.01). Training spent at high intensity was significantly related to relative speed improvements at 2 mmol·L−1 (r = 0.84, p < 0.001;) and 4 mmol·L−1 (r = 0.65, p = 0.001). Players spent almost two-thirds of their training time at low intensities. However, only the time spent at high intensity (>90% of maximal HR) was related to changes in aerobic fitness. These results support the usefulness of the quantification of aerobic training load using HR. Furthermore, it stresses the effectiveness of the high-intensity training in soccer.

Concurrent Validity of Vertical Jump Performance Assessment Systems

Abstract Castagna, C, Ganzetti, M, Ditroilo, M, Giovannelli, M, Rocchetti, A, and Manzi, V. Concurrent validity of vertical jump performance assessment systems. J Strength Cond Res 27(3): 761–768, 2013—The aim of this study was to examine the concurrent validity of 2 portable systems for vertical jump (VJ) assessment under field conditions. The VJ flight times assessed using an optical mat (Optojump) and an accelerometer-based (Myotest) system were compared with that of a force platform. The flight times recorded during a countermovement jump (CMJ) were collected from 20 rugby players (n = 86 jumps) concurrently using the 3 tracking systems. Significant bias between the Force platform and either the Optojump (bias = 0.006 ± 0.007; 95% confidence interval [CI] 0.004–0.007 seconds) and Myotest (bias = −0.031 ± 0.021; 95% CI 0.035 to −0.026s; p < 0.0001) occurred. A nearly perfect correlation was found between force platform and Optojump (r = 0.99; 95% CI 0.098–0.99; p < 0.0001). Force platform and Myotest (r = 0.89; 95% CI 0.084–0.93; p < 0.0001) flight times showed very large association. Difference between Optojump and Myotest systems was significant (−0.036 ± 0.021 seconds; 95% CI −0.041 to −0.032; p < 0.0001), which results in Myotest mean flight time being approximately 7.2% longer than the Optojump flight time. The association between Optojump and Myotest was nearly perfect (r = 0.91, 95% CI 0.86–0.94; p < 0.0001). This study showed that the Optojump and Myotest systems possess convergent validity and can be successfully used under field conditions to assess VJ while performing a CMJ. However, caution should be exercised when interpreting data obtained from different portable systems for field measurement.

Relation between Individualized Training Impulses and Performance in Distance Runners

PURPOSE The aim of this study was to develop a method to monitor responses to training loads on an individual basis in recreational long-distance runners (LDR) through training impulses (TRIMP) analysis. The hypothesis tested was that TRIMP on the basis of individually determined weighting factors could result in a better quantification of training responses and performance in LDR in comparison to methods on the basis of average-based group values. METHODS The training load responses of eight LDR (aged 39.9 +/- 6.5 yr) were monitored using a modified version of the average-based TRIMP called individualized TRIMP (TRIMPi) during a period of 8 wk. The TRIMPi was determined in each LDR using individual HR and lactate profiles determined during an incremental treadmill test. Training-induced effects on performance (5- and 10-km races) and changes in submaximal aerobic fitness (speeds at selected blood lactate concentrations of 2 and 4 mmol x L(-1)) were assessed before and at the end of the training intervention. RESULTS Speed at 2 mmol x L(-1) (+21.3 +/- 5.2%, P < 0.001) and 4 mmol x L(-1) (+10.6 +/- 2.4%, P < 0.01) concentrations significantly increased after training. Improvements in running speed (%) at 2 mmol x L(-1) (r = 0.87, P = 0.005) and 4 mmol x L(-1) (r = 0.74, P = 0.04) concentrations were significantly related to weekly TRIMPi sum. No significant relationship between any variable was detected when average-based group values were used. The TRIMPi was significantly related to 5000- (r = -0.77; P = 0.02) and 10,000-m track performances (r = -0.82; P = 0.01). CONCLUSIONS Individualized TRIMP is a valid tool in tracking fitness (speed at 2 and 4 mmol x L(-1)) and performance (i.e., 5000- and 10,000-m races) in LDR and is more valuable than the methods on the basis of average-based group values. TRIMPi could predict race performance in LDR.

EFFECT OF WHOLE BODY VIBRATION TRAINING ON LOWER LIMB PERFORMANCE IN SELECTED HIGH-LEVEL BALLET STUDENTS

The aim of this study was to examine the effects of 8 weeks of whole body vibration (WBV) training on vertical jump ability (CMJ) and knee-extensor performance at selected external loads (50, 70, and 100 kg; leg-press exercise) in elite ballerinas. Twenty-two (age, 21.25 ± 1.5 years) full-time ballerinas were assigned randomly to the experimental (E, n = 11) and control (C, n = 11) groups. The experimental group was submitted to WBV training 3 times per week before ballet practice. During the training period, the E and C groups undertook the same amount of ballet practice. Posttraining CMJ performance significantly increased in E group (6.3 ± 3.8%, p ≤ 0.001). Furthermore, E group showed significant (p ≤ 0.05–0.001) post- training average leg-press power and velocity improvements at all the external loads considered. Consequently, the force-velocity and power-velocity relationship shifted to the right after WBV training in the E group. The results of the present study show that WBV training is an effective short-term training methodology for inducing improvements in knee-extensor explosiveness in elite ballerinas.

Physiological responses to ball-drills in regional level male basketball players

Abstract The main aim of this study was to assess the physiological responses of male basketball players during usual basketball ball-drills. Fourteen male basketball players (age 18.9 ± 2.3 years) performed the following full-court (28 × 15 m) basketball ball-drills (3 × 4-min with 3-min passive rest): five-a-side (5v5), three-a-side (3v3) and two-a-side (2v2). A main effect (P < 0.0001) for ball-drills modes was evident for all variables (5v5 < 3v3 < 2v2). Mean [Vdot]O2 during the 5v5, 3v3 and 2v2 were 39.0 ± 7.2, 42.0 ± 7.5 and 45.0 ± 6.5 ml · kg−1 · min−1 (69 ± 11, 74 ± 12 and 79 ± 11% of [Vdot]O2peak) respectively (5v5 = 3v3 < 2v2, P < 0.001). Mean blood-lactate concentrations for 5v5, 3v3 and 2v2 were 4.2 ± 1.8, 6.2 ± 2.3 and 7.8 ± 1.2 mmol (l−1 respectively (5v5 < 3v3 < 2v2, P < 0.01). During the 5v5, 3v3 and 2v2 mean heart-rate (HR) was 84.0 ± 9.2, 88.0 ± 8.4 and 92.0 ± 5.6% of the individual peak respectively (5v5 < 3v3 < 2v2; P < 0.001). No significant differences were found between the regression-line slope (P = 0.86) and intercept (P = 0.45) of the HR-[Vdot]O2 relationships of the multistage maximal fitness test (r2 from 0.80 to 0.96, P < 0.001) and ball-drills (r2 from 0.70 to 0.95, P < 0.001) conditions. Reducing the number of players over the same playing court resulted in increments in physiological demands. The 2v2 condition provided responses in the range of those reported to improve aerobic and anaerobic fitness. The aerobic demands of ball-drills can be accurately assessed using heart-rate monitoring in basketball.