Screening young athletes for prevention of sudden cardiac death: Practical recommendations for sports physicians.

Regular intensive exercise in athletes increases the relative risk of sudden cardiac death (SCD) compared with the relatively sedentary population. Most cases of SCD are due to silent cardiovascular diseases, and pre-participation screening of athletes at risk of SCD is thus of major importance. However, medical guidelines and recommendations differ widely between countries. In Italy, the National Health System recommends pre-participation screening for all competitive athletes including personal and family history, a physical examination, and a resting 12-lead electrocardiogram (ECG). In the United States, the American College of Cardiology and the American Heart Association recommend a pre-participation screening program limited to the use of specific questionnaires and a clinical examination. The value of a 12-lead ECG is debated based on issues surrounding cost-efficiency and feasibility. The aim of this review was to focus on (i) the incidence rate of cardiac diseases in relation to SCD; (ii) the value of conducting a questionnaire and a physical examination; (iii) the value of a 12-lead resting ECG; (iv) the importance of other cardiac evaluations in the prevention of SCD; and (v) the best practice for pre-participation screening.

Optimizing strength training for running and cycling endurance performance: A review.

Here we report on the effect of combining endurance training with heavy or explosive strength training on endurance performance in endurance-trained runners and cyclists. Running economy is improved by performing combined endurance training with either heavy or explosive strength training. However, heavy strength training is recommended for improving cycling economy. Equivocal findings exist regarding the effects on power output or velocity at the lactate threshold. Concurrent endurance and heavy strength training can increase running speed and power output at VO2max (Vmax and Wmax, respectively) or time to exhaustion at Vmax and Wmax. Combining endurance training with either explosive or heavy strength training can improve running performance, while there is most compelling evidence of an additive effect on cycling performance when heavy strength training is used. It is suggested that the improved endurance performance may relate to delayed activation of less efficient type II fibers, improved neuromuscular efficiency, conversion of fast-twitch type IIX fibers into more fatigue-resistant type IIA fibers, or improved musculo-tendinous stiffness.

Effect of training cessation on muscular performance: a meta-analysis.

The purpose of this study was to assess the effect of resistance training cessation on strength performance through a meta-analysis. Seven databases were searched from which 103 of 284 potential studies met inclusion criteria. Training status, sex, age, and the duration of training cessation were used as moderators. Standardized mean difference (SMD) in muscular performance was calculated and weighted by the inverse of variance to calculate an overall effect and its 95% confidence interval (CI). Results indicated a detrimental effect of resistance training cessation on all components of muscular performance: [submaximal strength; SMD (95% CI) = -0.62 (-0.80 to -0.45), P < 0.01], [maximal force; SMD (95% CI) = -0.46 (-0.54 to -0.37), P < 0.01], [maximal power; SMD (95% CI) = -0.20 (-0.28 to -0.13), P < 0.01]. A dose-response relationship between the amplitude of SMD and the duration of training cessation was identified. The effect of resistance training cessation was found to be larger in older people (> 65 years old). The effect was also larger in inactive people for maximal force and maximal power when compared with recreational athletes. Resistance training cessation decreases all components of muscular strength. The magnitude of the effect differs according to training status, age or the duration of training cessation.

Examination of fatigue development in elite soccer in a hot environment: a multi-experimental approach.

The study examines fatigue in elite soccer played in hot conditions. High-profile soccer players (n=20) were studied during match play at ∼31 °C. Repeated sprint and jump performances were assessed in rested state and after a game and activity profile was examined. Additionally, heart rate (HR), blood lactate, muscle temperature and body mass changes were determined. Repeated sprint and jump performances were reduced (P<0.05) by 2.6% and 8.2%, respectively, after the game. The fatigue index in the repeated sprint test was 6.0±0.7% after the game compared with 1.7±1.0% at rest (P<0.05). High-intensity running was 57±4% lower (P<0.05) during the last 15-min interval of the game compared with the first 15-min period. No differences were observed in mean HR or blood lactates between halves. Muscle temperature was 40.5±0.4 °C after the first half, which was 0.8±0.2 °C higher (P<0.05) than after the second half. Net fluid loss during the game was >2% of the body mass. Correlations were observed between net-fluid loss and repeated sprint test fatigue index after the game (r=0.73, P<0.05) and Yo-Yo intermittent recovery, level 1 test performance and high-intensity running during the final 15 min of the game (r=0.51, P<0.05). The study provides direct evidence of compromised repeated sprint and jump performances induced by soccer match play and pronounced reduction in high-intensity running toward the end of an elite game played in a hot environment. This fatigue could be associated training status and hyperthermia/dehydration.

Intense training: the key to optimal performance before and during the taper.

The training load is markedly reduced during the taper so that athletes recover from intense training and feel energized before major events. Load reduction can be achieved by reducing the intensity, volume and/or frequency of training, but with reduced training load there may be a risk of detraining. Training at high intensities before the taper plays a key role in inducing maximal physiological and performance adaptations in both moderately trained subjects and highly trained athletes. High-intensity training can also maintain or further enhance training-induced adaptations while athletes reduce their training before a major competition. On the other hand, training volume can be markedly reduced without a negative impact on athletes' performance. Therefore, the training load should not be reduced at the expense of intensity during the taper. Intense exercise is often a performance-determining factor during match play in team sports, and high-intensity training can also elicit major fitness gains in team sport athletes. A tapering and peaking program before the start of a league format championship or a major tournament should be characterized by high-intensity activities.

A comparative study between serve mode and speed and its effectiveness in a high-level volleyball tournament.

AIM: This study carries out a comparative analysis between serve mode and speed and its effectiveness at the 2004 Men's Olympic Qualification Tournament. METHODS: A total of 377 serves were analysed, 124 of which belonged to Cuba vs Holland, 63 to Spain vs Cameroon, 100 to Spain vs Cuba, and 91 to Holland vs Cameroon. Serve were recorded using a tripod mounted radar gun. RESULTS: The analysis has shown the predominance of jump serve (JUMP, 84.9%) compared with float serve with jump (FLOAT JUMP, 5.6%) and float serve (FLOAT, 9.5%). Only 25.3% of the total jump serves analysed was successfully stricken back making the first tempo attack possible. The respective percentages for FLOAT JUMP and FLOAT were 42.9% and 55.6%. Ball speed in JUMP (23.03+/-3.94 m.s(-1)) was markedly higher compared with FLOAT JUMP and FLOAT (12.05+/-3.44 m.s(-1) and 11.47+/-4.22 m.s(-1)). While negative outcomes (66.7%) in FLOAT stand out, a better balance between negative and positive outcomes were found in both JUMP (50%) and FLOAT JUMP (42.9%). However, no relationship was found between serve speed and its effectiveness outcome (R2=0 in the overall sample and R2=0.005, when pooling the five serve effectiveness categories into negative and positive outcomes. In fact, JUMP was mainly performed in the span of velocities between 23.06 and 28.06 m.s(-1) in both error and direct point categories. CONCLUSION: We found no significant relationship between serve velocity and a better outcome related to effectiveness. In addition, JUMP and FLOAT JUMP present a better balance between negative and positive outcomes compared with FLOAT.

Physique traits of lightweight rowers and their relationship to competitive success.

OBJECTIVES: Physique traits and their relationship to competitive success were assessed amongst lightweight rowers competing at the 2003 Australian Rowing Championships. METHODS: Full anthropometric profiles were collected from 107 lightweight rowers (n = 65 males, n = 45 females) competing in the Under 23 and Open age categories. Performance assessments were obtained for 66 of these rowers based on results in the single sculls events. The relationship between physique traits and competitive success was then determined. RESULTS: Lower body fat (heat time estimate -8.4 s kg(-1), p<0.01), greater total body mass (heat time estimate -4.4 s kg(-1), p = 0.03), and muscle mass (heat time estimate -10.2 s kg(-1), p<0.01) were associated with faster 2000 m heat times. CONCLUSIONS: The more successful lightweight rowers were those who had lower body fat and greater total muscle mass.

Physiological and performance benefits of halftime cooling.

This study examined the effect of a 10-min, halftime cooling application on physiological and psychological parameters known to affect performance. Fourteen volunteers (10 male, 4 female) completed two randomised trials 48 hr to 7 days apart. Trials consisted of a 1-hr cycling protocol: 30 min at 75% VO2max followed by 10 min cooling (application of a cooling jacket) or passive recovery (control), and a second 30-min exercise bout consisting of 20 min at 75% VO2max, immediately followed by a 10-min maximal effort, where work was measured as energy expended (kJ). Performance of the 10-min maximal intensity phase tended to improve (171.5 +/- 30.4 kJ vs 165.4 +/- 29.2 kJ, p = 0.087) following the cooling trial. Heart rate during the 5th min of the maximal effort, (183 +/- 9 beats.min(-1) vs 180 +/- 7 beats.min(-1), p = 0.024), blood lactate concentration at 6 min post-exercise (9.3 +/- 3.1 mmolxL(-1) vs 7.9 +/- 3.2 mmolxL(-1), p = 0.007), rating of perceived exertion at the 20th min post-halftime recovery (15 +/- 2 vs 16 +/- 2, p = 0.042), and subjective rating of feelings and emotions differed between the cooling and control conditions. Sweat loss, core and mean skin temperature and rating of thermal sensation failed to differ significantly between conditions. Halftime cooling tended to result in greater aerobic performance. Psychological assessment revealed a dramatic placebo effect from the cooling application confounding these results. Furthermore, the cooling intervention failed to induce any significant thermoregulatory effects.

Physiological variables to use in the gender comparison in highly trained runners.

AIM: The aims of this investigation were to compare physiological characteristics between highly trained middle-distance and marathon male (n=17) and female (n=11) runners; to determine the most suitable variables to use in the gender comparison in these subjects, considering physical difference between genders; and to indicate some of the best predictors of performance in running events in which oxidative metabolism prevails. METHODS: Subjects performed a progressive maximal exercise on the treadmill to determine maximal oxygen uptake (VO(2max)) and velocities corresponding to a blood lactate concentration of 4 mmol x L(-1) (upsilon(OBLA)) and to the lactate threshold (upsilon(LT)). Cost of running (Cr) and maximal aerobic velocity (upsilon(a max)) were calculated from VO(2) measurements. RESULTS: Males presented higher VO(2max), upsilon(a max), upsilon(OBLA), upsilon(LT), and VO(2) @ upsilon(OBLA) and upsilon(LT) (p<0.001), but females had higher upsilon(OBLA) and upsilon(LT) (p<0.01) expressed as %VO(2max). upsilon(a max) correlated with performance time relative to the world record in both, females (r=-0.77, p<0.01) and males (r=-0.58, p<0.05); and upsilon(LT) with performance only in males (r=-0.59, p<0.05). CONCLUSION: In conclusion, female athletes seemed to compensate partly their aerobic profile with higher %VO(2max) @ u(OBLA) and u(LT), suggesting that both maximal and submaximal physiological variables should be considered when evaluating and comparing highly trained athletes of both genders. upsilon(a max) is one of the best predictors of performance in running events in which oxidative metabolism prevails.

Comparative analysis of viral pathogens and potential indicators in shellfish.

Shellfish can be responsible of outbreaks of infectious diseases and current health measures do not guarantee the absence of viral pathogens in this product. Here we examine the presence of pathogenic viruses and potential indicators in shellfish in a comparative analysis.Sixty shellfish samples collected in three areas with different levels of faecal contamination were analysed for Escherichia coli, total coliforms, Clostridium perfringens, somatic coliphages, F-specific phages of RNA (F-RNA), bacteriophages infecting Bacteroides fragilis RYC2056, human adenovirus, enterovirus and hepatitis A virus (HAV). Viruses were eluted in a glycine buffer at pH 10. The overall percentage of viral pathogens detected was 47% for human adenoviruses, 19% for enteroviruses and 24% for HAV. Since all the samples positive for enterovirus and HAV were also positives for human adenovirus, the latter may be considered useful as a molecular index of viral contamination in shellfish. No significant differences in the bioaccumulation of bacteria and bacteriophages for oysters or mussels were observed. It was found that the probability of detection of any of the pathogenic virus decreases as the temperature of shellfish growing waters increases. However, the probability of detecting viruses increases when phages of B. fragilis are found. Although more data are needed in order to fulfil the need of viral indicators for controlling the presence of human viruses in shellfish, the obtained results indicate that phages infecting B. fragilis RYC2056 could be a suitable group of bacteriophages to be used as an indicator of the presence of viruses in shellfish.

Swimming performance changes during the final 3 weeks of training leading to the Sydney 2000 Olympic Games.

The purpose of this study was to determine the magnitude of the swimming performance change during the final 3 weeks of training (F3T) leading to the Sydney 2000 Olympic Games. Olympic swimmers who took part in the same event or events at the Telstra 2000 Grand Prix Series in Melbourne, Australia, (26 - 27 August 2000), and 21 - 28 d later at the Sydney 2000 Olympic Games (16 - 23 September 2000) were included in this analysis. A total of 99 performances (50 male, 49 female) were analysed. The overall performance improvement between pre- and post-F3T conditions for all swimmers was 2.18 +/- 1.50 % (p < 0.0001), (range - 1.14 % to 6.02 %). A total of 91 of the 99 analysed performances were faster after the F3T and only 8 were slower. The percentage improvement with F3T was significantly higher (P < 0.01) in males (2.57 +/- 1.45 %) than in females (1.78 +/- 1.45 %). In conclusion, the pre-Olympic F3T elicited a significant performance improvement of 2.57 % for male and 1.78 % for female swimmers at the Sydney 2000 Olympic Games. The magnitude was similar for all competition events, and was achieved by swimmers from different countries and performance levels. These data provide a quantitative framework for coaches and swimmers to set realistic performance goals based on individual performance levels before the final training phase leading to important competitions.

Physiological and performance responses to a 6-day taper in middle-distance runners: influence of training frequency.

The purpose of this investigation was to examine the influence of training frequency on performance and some physiological responses during a 6-day taper. After 18 weeks of training, 9 male middle-distance runners were assigned to a high frequency taper (HFT, n = 5) or a moderate frequency taper (MFT, n = 4), consisting of training daily or resting every third day of the taper. Taper consisted of an 80% nonlinear progressive reduction in high intensity interval training. Blood samples were obtained, and 800 m performance and peak blood lactate ([La] peak ) measured before and after taper. Performance improved significantly after HFT (121.8 +/- 4.7 vs 124.2 +/- 4.9 s, p < 0.05), but not after MFT (126.6 +/- 2.8 vs 127.1 +/- 2.1 s). Neutrophils (2.89 +/- 0.68 vs 2.56 +/- 0.61 10 (3) x mm(-3)), granulocytes (3.08 +/- 0.70 vs 2.77 +/- 0.66 10 (3) x mm(-3)), haptoglobin (79.7 +/- 47.9 vs 60.7 +/- 33.6 mg x dl(-1)), total testosterone (7.39 +/- 1.67 vs 5.52 +/- 0.88 microg x l(-1)) and [La] peak (15.5 +/- 1.5 vs 14.4 +/- 2.0 mmol x l(-1)) significantly increased with taper. [La] peak correlated with performance time before taper (r = -0.76, p < 0.05), and change in [La] peak with change in serum cortisol (r = -0.75, p < 0.05) and total testosterone:cortisol ratio (r = 0.82, p < 0.01). In conclusion, training daily during a 6-day taper brought about significant performance gains, whereas resting every third day did not. High [La] peak and a hormonal milieu propitious to anabolic processes seemed to be necessary for optimum performance.

Depuration dynamics of viruses in shellfish.

The consumption of shellfish has been associated with viral infections even in cases where shellfish complied with the current regulation, which is based on bacterial analysis. In this study, depuration rates of potential indicators and human viruses have been analysed in order to study the use of complementary parameters for evaluating the microbiological quality of depurated shellfish. Depuration of naturally highly polluted mussels has been evaluated and analyses for Escherichia coli, Clostridium perfringens, somatic coliphages, F-RNA phages and bacteriophages infecting Bacteroides fragilis RYC2056 and HSP40, human adenovirus, enterovirus have been done. Seawater of the depuration tank was disinfected by UV irradiation, ozone and passed through a skimmer and a biological filter. The correct functioning of the depuration tank was monitored by the quantification of total organic carbon (TOC), NH4+ and total aerobic bacteria in the seawater. To study the relation between the bacteriophages and the human viruses analysed, a logistic regression model was applied. F-RNA phages are significantly related to human adenoviruses and enteroviruses. Thus, they can be used as a complementary parameter for evaluating the efficiency of the depuration treatment. Somatic coliphages are also significantly associated with enteroviruses. Bacteriophages infecting B. fragilis HSP40 were analysed by the double-agar-layer (DAL) method, which quantifies infectious viruses, and by nested PCR, which detects the presence of the genome of these phages. The highest sensitivity of the molecular techniques was demonstrated and the results obtained are an indicator of a close relation between positive results by PCR and the presence of infectious viral particles in shellfish. All shellfish samples were negative for human viruses by PCR after 5 days of depuration treatment and the results obtained applying a regression model also showed negative results or nearly for F-RNA phages and bacteriophages infecting B. fragilis RYC2056. Thus, in this specific depuration treatment, 5 days may be necessary to assess the sanitary quality of shellfish.

Influence of body mass and height on the energy cost of running in highly trained middle- and long-distance runners.

Previous studies about the influence of body dimensions on running economy have not compared athletes specialized in different competition events. Therefore, the purpose of the present study was to assess the influence of body mass (m(b)) and height (h) on the energy cost of running (Cr) in 38 highly trained male runners, specialized in either marathon (M, n = 12), long middle-distance (5000 - 10000 m, LMD, n = 14) or short middle-distance (800 - 1500 m, SMD, n = 12), and to assess possible differences in body dimensions for each event. Subjects performed a progressive maximal exercise on the treadmill to determine oxygen uptake VO(2)) at different submaximal velocities and maximal oxygen uptake VO(2)max). Cr was calculated from VO(2) measurements. LMD runners had significantly higher mean Cr (0.192 +/- 0.007, 0.182 +/- 0.009, and 0.180 +/- 0.009 ml O(2) x kg(-1) x m(-1) for LMD, M and SMD, respectively) and VO(2)max (74.1 +/- 3.7, 68.5 +/- 2.9 and 69.7 +/- 3.4 ml x kg (-1) x min (-1)). Cr correlated with h (r = -0.86, p < 0.001) and m(b) (r = -0.77, p < 0.01) only in the SMD group. In conclusion, these data suggest that highly trained distance runners tend to show counterbalancing profiles of running economy and VO(2)max (the higher Cr, the higher VO(2) max and vice versa), and that anthropometric characteristics related with good performance are different in long-distance and middle-distance events.

Muscular characteristics of detraining in humans.

Skeletal muscle is characterized by its ability to dynamically adapt to variable levels of functional demands. During periods of insufficient training stimulus, muscular detraining occurs. This may be characterized by a decreased capillary density, which could take place within 2--3 wk of inactivity. Arterial-venous oxygen difference declines if training stoppage continues beyond 3--8 wk. Rapid and progressive reductions in oxidative enzyme activities bring about a reduced mitochondrial ATP production. The above changes are related to the reduction in VO(2max) observed during long-term training cessation. These muscular characteristics remain above sedentary values in the detrained athlete but usually return to baseline values in recently trained individuals. Glycolytic enzyme activities show nonsystematic changes during periods of training cessation. Fiber distribution remains unchanged during the initial weeks of inactivity, but oxidative fibers may decrease in endurance athletes and increase in strength-trained athletes within 8 wk of training stoppage. Muscle fiber cross-sectional area declines rapidly in strength and sprint athletes, and in recently endurance-trained subjects, whereas it may increase slightly in endurance athletes. Force production declines slowly and in relation to decreased EMG activity. Strength performance in general is readily maintained for up to 4 wk of inactivity, but highly trained athletes' eccentric force and sport-specific power, and recently acquired isokinetic strength, may decline significantly.

Physiological and performance characteristics of male professional road cyclists.

Male professional road cycling competitions last between 1 hour (e.g. the time trial in the World Championships) and 100 hours (e.g. the Tour de France). Although the final overall standings of a race are individual, it is undoubtedly a team sport. Professional road cyclists present with variable anthropometric values, but display impressive aerobic capacities [maximal power output 370 to 570 W, maximal oxygen uptake 4.4 to 6.4 L/min and power output at the onset of blood lactate accumulation (OBLA) 300 to 500 W]. Because of the variable anthropometric characteristics, 'specialists' have evolved within teams whose job is to perform in different terrain and racing conditions. In this respect, power outputs relative to mass exponents of 0.32 and 1 seem to be the best predictors of level ground and uphill cycling ability, respectively. However, time trial specialists have been shown to meet requirements to be top competitors in all terrain (level and uphill) and cycling conditions (individually and in a group). Based on competition heart rate measurements, time trials are raced under steady-state conditions, the shorter time trials being raced at average intensities close to OBLA (approximately 400 to 420 W), with the longer ones close to the individual lactate threshold (LT, approximately 370 to 390 W). Mass-start stages, on the other hand, are raced at low mean intensities (approximately 210 W for the flat stages, approximately 270 W for the high mountain stages), but are characterised by their intermittent nature, with cyclists spending on average 30 to 100 minutes at, and above LT, and 5 to 20 minutes at, and above OBLA.

Exercise intensity and load during mass-start stage races in professional road cycling.

PURPOSE: To evaluate exercise intensity and load during mass-start stages in professional road cycling, using competition heart rate (HR) recordings. METHODS: Seventeen world-class cyclists performed an incremental laboratory test during which maximal power output (Wmax), maximal HR (HRmax), onset of blood lactate accumulation (OBLA), lactate threshold (LT), and a HR-power output relationship were assessed. An OBLAZONE (HROBLA +/- 3 beats.min-1) and an LTZONE (HRLT +/- 3 beats.min-1) were described. HR was monitored during 125 flat (< 13 km uphill, < 800-m altitude change; FLAT), 99 semi-mountainous (13-35 km uphill, 800- to 2000-m altitude change; SEMO), and 86 high-mountain (> 35 km uphill, > 2000-m altitude change; HIMO) stages. Each cyclist's competition power output was estimated from competition HR and individual HR-power output relationships. Competition training impulse (TRIMP) values and time spent at "easy," "moderate," and "hard" zones were estimated from HR and race duration. RESULTS: Average %HRmax were 61 +/- 5%, 58 +/- 6%, and 51 +/- 7% in HIMO, SEMO, and FLAT stages, respectively, and estimated average power outputs were 246 +/- 44, 234 +/- 43, and 192 +/- 45 W. Competition HR values relative to HROBLA and HRLT were, respectively, 69 +/- 6, 79 +/- 9% in HIMO; 65 +/- 7, 74 +/- 11% in SEMO; and 57 +/- 8, 65 +/- 10% in FLAT stages. The amount of TRIMP in HIMO, SEMO, and FLAT stages were, respectively, 215 +/- 38, 172 +/- 31, and 156 +/- 31. Percentage time spent in the "moderate" and "hard" zones was highest in HIMO (22 +/- 14, 5 +/- 6%) followed by SEMO (15 +/- 13, 5 +/- 5%) and FLAT (9 +/- 7, 2 +/- 2%) stages. CONCLUSIONS: %HRmax, time distribution around HROBLA and HRLT, TRIMP, and load zones reflected the physiological demands of different mass-start cycling stage categories. The knowledge of these demands could be useful for planning precompetition training strategies.

Cardiorespiratory and metabolic characteristics of detraining in humans.

Detraining can be defined as the partial or complete loss of training-induced adaptations, in response to an insufficient training stimulus. Detraining is characterized, among other changes, by marked alterations in the cardiorespiratory system and the metabolic patterns during exercise. In highly trained athletes, insufficient training induces a rapid decline in VO2max, but it remains above control values. Exercise heart rate increases insufficiently to counterbalance the decreased stroke volume resulting from a rapid blood volume loss, and maximal cardiac output is thus reduced. Cardiac dimensions are also reduced, as well as ventilatory efficiency. Consequently, endurance performance is also markedly impaired. These changes are more moderate in recently trained subjects in the short-term, but recently acquired VO2max gains are completely lost after training stoppage periods longer than 4 wk. From a metabolic viewpoint, even short-term inactivity implies an increased reliance on carbohydrate metabolism during exercise, as shown by a higher exercise respiratory exchange ratio. This may result from a reduced insulin sensitivity and GLUT-4 transporter protein content, coupled with a lowered muscle lipoprotein lipase activity. These metabolic changes may take place within 10 d of training cessation. Resting muscle glycogen concentration returns to baseline within a few weeks without training, and trained athletes' lactate threshold is also lowered, but still remains above untrained values.

Viral contamination of shellfish: evaluation of methods and analysis of bacteriophages and human viruses.

Viral outbreaks attributed to the consumption of contaminated shellfish have been clearly demonstrated. Thirty-five samples of mussels collected from areas with two different levels of faecal pollution were analysed for somatic coliphages, F-RNA phages and bacteriophages infecting Bacteroides fragilis HSP40 and RYC2056 following standardised protocols, and for enterovirus, human adenovirus and hepatitis A virus by nucleic acid amplification (Nested-PCR and RT-PCR). Four methods for viral recovery from shellfish have been compared. The first method is based on borate buffer at pH 9.5 as eluent, the second is based on glycine buffer at pH 10 as eluent, a third method is based on glycine buffer at pH 7.5 and changes in conductivity and the fourth method on nutritive broth with Tween 80 as eluent. The results obtained were analysed statistically and the method based in glycine buffer at pH 10 seems to be the most efficient and useful for the recovery of phages and human viruses. The results also show a different pattern in the proportions between the viral parameters when the source of the faecal pollution is close to or distant from the shellfish growing area.