Fabio Pigozzi

Conversion From Vagal to Sympathetic Predominance With Strenuous Training in High-Performance World Class Athletes

Background—Benefits of moderate endurance training include increases in parasympathetic activity and baroreflex sensitivity (BRS) and a relative decrease in sympathetic tone. However, the effect of very intensive training load on neural cardiovascular regulation is not known. We tested the hypothesis that strenuous endurance training, like in high-performance athletes, would enhance sympathetic activation and reduce vagal inhibition. Methods and Results—We studied the entire Italian junior national team of rowing (n=7) at increasing training loads up to 75% and 100% of maximum, the latter ∼20 days before the Rowing World Championship. Autoregressive power spectral analysis was used to investigate RR interval and blood pressure (BP) variabilities. BRS was assessed by the sequences method. Increasing training load up to 75% of maximum was associated with a progressive resting bradycardia and increased indexes of cardiac vagal modulation and BRS. However, at 100% training load these effects were reversed, with increases in resting heart rate, diastolic BP, low-frequency RR interval, and BP variabilities and decreases in high-frequency RR variability and BRS. Three athletes later won medals in the World Championship. Conclusions—This study indicates that very intensive endurance training shifted the cardiovascular autonomic modulation from a parasympathetic toward a sympathetic predominance. This finding should be interpreted within the context of the substantial role played by the sympathetic nervous system in increasing cardiovascular performance at peak training. Whether the altered BP and autonomic function shown in this study might be in time hazardous to human cardiovascular system remains to be established.

The effects of a whole-body vibration program on muscle performance and flexibility in female athletes

Fagnani F, Giombini A, Di Cesare A, Pigozzi F, Di Salvo V: The effects of a whole-body vibration program on muscle performance and flexibility in female athletes. Am J Phys Med Rehabil 2006;85:956–962. Objective:This randomized controlled study was designed to investigate the short-term effects of an 8-wk whole-body vibration protocol on muscle performance and flexibility in female competitive athletes. Design:Twenty-six young volunteer female athletes (ages 21–27 yrs) were randomized to either the vibration group or control group. The vibration intervention consisted of an 8-wk whole-body vibration 3 times a week employed by standing on a vertical vibration platform. As outcome measures, three performance tests (counter-movement jump, extension strength of lower extremities with an isokinetic horizontal leg press, and a sit-and-reach test for flexibility) were performed initially and after 8 wks. Results:A total of 24 athletes completed the study properly. In the vibration group (n = 13) whole-body vibration induced significant improvement of bilateral knee extensor strength (P < 0.001), counter-movements jump (P < 0.001), and flexibility (P < 0.001) after 8 wks of training. No significant changes were found for all the outcome measures for the control group (n = 11). Conclusions:Whole-body vibration is a suitable training method to improve knee extension maximal strength, counter-movement jump, and flexibility in a young female athlete if it is properly designed. Not only do the optimal frequency, amplitude, and g-forces need to be identified but also the level of muscle activation that would benefit more from vibration stimulation. The improvement of flexibility is important not only for performance but also for the prevention of muscle-tendon injury.

Sprinting analysis of elite soccer players during European Champions League and UEFA Cup matches

Abstract It has been suggested that assessment of high-intensity activities during a match is a valid measure of physical performance in elite soccer. Recently, sprinting activities have been analysed in more depth. The aim of this study was to develop a detailed analysis of the sprinting activities of different playing positions during European Champions League and UEFA Cup competitions. Altogether, 717 elite outfield soccer players were evaluated throughout 2002–2006 using ProZone® (Leeds, UK). Sprinting (explosive and leading) was analysed for each playing position. To compare positional differences, a Kruskal-Wallis analysis was performed. Differences were found among positions for total number of sprints and total sprint distance covered: wide midfielders > (attackers = wide defenders) > central midfielders > central defenders (P < 0.001), as well as for explosive sprints: (wide midfielders = attackers = wide defenders) > central defenders, wide midfielders > central midfielders > central defenders and attackers = wide defenders = central midfielders (P < 0.001), and leading sprints: wide midfielders > (attackers = wide defenders) > central midfielders > central defenders (P < 0.001). For each group, there were no differences in ratio of explosive to leading sprints. Wide midfielders performed a higher number of sprints in all five distance categories than all other positions. This study showed that sprinting characteristics are influenced by position. Wide midfielders have to complete additional high-intensity activities during training sessions compared with the other positions to achieve the performance level required during the match.

ESC study group of sports cardiology position paper on adverse cardiovascular effects of doping in athletes.

The use of doping substances and methods is extensive not only among elite athletes, but also among amateur and recreational athletes. Many types of drugs are used by athletes to enhance performance, to reduce anxiety, to increase muscle mass, to reduce weight or to mask the use of other drugs during testing. However, the abuse of doping substances and methods has been associated with the occurrence of numerous health side-effects. The adverse effects depend on the type of the consumed drug, as well as the amount and duration of intake and the sensitivity of the body, since there is a large inter-individual variability in responses to a drug. Usually the doses used in sports are much higher than those used for therapeutic purposes and the use of several drugs in combination is frequent, leading to higher risk of side-effects. Among biomedical side-effects of doping, the cardiovascular ones are the most deleterious. Myocardial infarction, hyperlipidemia, hypertension, thrombosis, arrythmogenesis, heart failure and sudden cardiac death have been noted following drug abuse. This paper reviews the literature on the adverse cardiovascular effects after abuse of prohibited substances and methods in athletes, aiming to inform physicians, trainers and athletes and to discourage individuals from using drugs during sports.

Platelet-Rich Plasma in Muscle Healing

The muscle healing process is defined as a complex and dynamic process resulting in the restoration of anatomic continuity and function. This process is characterized by a cascade of events triggered by the tissue injury itself. It is widely accepted that growth factors play a central role in the healing processes by modulating the recruitment, duplication, activation, and differentiation of different cell types. This observation is the basis on which the use of platelet-rich plasma in several circumstances is founded; all of them requiring the activation or the modulation of the tissue repair process. There is an extensive documentation of in vitro and in vivo studies demonstrating the safety and efficacy of growth factors in the muscle healing process. Unfortunately, the precise biological efficacy and the lack of long-term side effects have not been clearly demonstrated. With regard to sports medicine, doping-related issues are still a matter of debate, especially regarding the treatment of muscle injuries. The purpose of this review is to examine the role of growth factors during muscle healing processes and to discuss the implications of platelet-rich plasma in its therapeutic applications. Sports medicine issues are also discussed particularly with regard to antidoping regulations.

Snowboard Traumatology: An Epidemiological Study

In the past 10 years, snowboarding has become a popular winter sport among young people, and the number of accidents has increased proportionately. The incidence of traumas from snowboarding is shown to be 4 to 6 for every 1000 medical examinations, which is similar to that of downhill skiing. However, other important statistical differences exist between the two sports. This study of 106 snowboarding-related injury cases analyzes the epidemiology of these injuries in Italy. Results found that 45.1% of injuries are located in the upper limbs and that significant advantages are obtained with the introduction of guards to protect the upper limbs during descent. Serious ligament injuries to the knee are more rare in snowboarding than in downhill skiing. In both sports, injuries are more common with rigid boots, which lead to a higher incidence of injury to the upper limbs. Finally, a high percentage of injury to beginners was found in this study. Training courses for those who are considering taking up the sport of snowboarding could significantly lower their risk of trauma.

Match Performance Comparison in Top English Soccer Leagues

The purpose of this study was to compare motions of soccer players in the English Premier (1st) and Championship (2nd) League. A total of 26 449 observations were obtained from players during 4 seasons (2006-2010) in the 2 leagues. Time-motions of all players (attackers, central defenders, central midfielders, wide defenders, wide midfielders) were recorded during each match using the Prozone® System, (Leeds, UK), and categorized by speed intensity. Number of actions, total distance and the mean distance covered at each speed intensity were measured. Players in the Championship league covered a total match distance of 11.1±0.9 km compared with 10.8±1.0 km for players from the Premiership (p<0.001). Championship players also covered greater distances during jogging, running, high-speed running, and sprinting. Premiership players covered more distance walking. Players in the Soccer League Championship had more instances of each condition. Although these differences were statistically significant, they were negligible in practical terms, suggesting match-related activities do not explain the general superiority of Premiership players over Championship players in England.

Muscle metaboreflex contribution to cardiovascular regulation during dynamic exercise in microgravity: insights from mission STS‐107 of the space shuttle Columbia

One of the most important features of prolonged weightlessness is a progressive impairment of muscular function with a consequent decrease in exercise capacity. We tested the hypothesis that the impairment in musculo‐skeletal function that occurs in microgravity results in a potentiation of the muscle metaboreflex mechanism and also affects baroreflex modulation of heart rate (HR) during exercise. Four astronauts participating in the 16 day Columbia shuttle mission (STS‐107) were studied 72–71 days before launch and on days 12–13 in‐flight. The protocol consisted of 6 min bicycle exercise at 50% of individual followed by 4 min of postexercise leg circulatory occlusion (PECO). At rest, systolic (S) and diastolic (D) blood pressure (BP), R‐R interval and baroreflex sensitivity (BRS) did not differ significantly between pre‐ and in‐flight measurements. Both pre‐ and in‐flight, SBP increased and R‐R interval and BRS decreased during exercise, whereas DBP did not change. During PECO preflight, SBP and DBP were higher than at rest, whereas R‐R interval and BRS recovered to resting levels. During PECO in‐flight, SBP and DBP were significantly higher whereas R‐R interval and BRS remained significantly lower than at rest. The part of the SBP response (Δ) that was maintained by PECO was significantly greater during spaceflight than before (34.5 ± 8.8 versus 13.8 ± 11.9 mmHg, P= 0.03). The tachycardic response to PECO was also significantly greater during spaceflight than preflight (−141.5 ± 25.2 versus−90.5 ± 33.3 ms, P= 0.02). This study suggests that the muscle metaboreflex is enhanced during dynamic exercise in space and that the potentiation of the muscle metaboreflex affects the vagally mediated arterial baroreflex contribution to HR control.

Sudden Death in Competitive Athletes

Sudden death in athletes is an extremely rare event yet no less tragic for its infrequency. Up to 90% of these deaths are due to underlying cardiovascular diseases and therefore categorized as sudden cardiac death (SCD). The causes of SCD among athletes are strongly correlated with age. In young athletes (<35 years), the leading causes are congenital cardiac diseases, particularly hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and congenital coronary artery anomalies. By contrast, most of deaths in older athletes (<35 years) are due to coronary artery disease. This review focuses on the cardiac causes of SCD and provides a brief summary of the principal noncardiac causes. Current pre-participation screening strategies are also discussed, with particular emphasis on the Italian experience.

Role of exercise stress test in master athletes

Background: The effectiveness of cardiovascular screening in minimising the risk of athletic field deaths in master athletes is not known. Objective: To evaluate the prevalence and clinical significance of ST segment depression during a stress test in asymptomatic apparently healthy elderly athletes. Methods: A total of 113 male subjects aged over 60 were studied (79 trained and 34 sedentary); 88 of them (62 trained and 26 sedentary) were followed up for four years (mean 2.16 years for athletes, 1.26 years for sedentary subjects), with a resting 12 lead electrocardiogram (ECG), symptom limited exercise ECG on a cycle ergometer, echocardiography, and 24 hour ECG Holter monitoring. Results: A significant ST segment depression at peak exercise was detected in one athlete at the first evaluation. A further case was seen during the follow up period in a previously “negative” athlete. Both were asymptomatic, and single photon emission tomography and/or stress echocardiography were negative for myocardial ischaemia. The athletes remained symptom-free during the period of the study. One athlete died during the follow up for coronary artery disease: he showed polymorphous ventricular tachycardia during both the exercise test and Holter monitoring, but no significant ST segment depression. Conclusions: The finding of false positive ST segment depression in elderly athletes, although still not fully understood, may be related to the physiological cardiac remodelling induced by regular training. Thus athletes with exercise induced ST segment depression, with no associated symptoms and/or complex ventricular arrhythmias, and no adverse findings at second level cardiological testing, should be considered free from coronary disease and safe to continue athletic training.