Vernon Neville

Salivary IgA as a risk factor for upper respiratory infections in elite professional athletes.

UNLABELLED The relationship between physiological and psychological stress and immune function is widely recognized; however, there is little evidence to confirm a direct link between depressed immune function and incidence of illness in athletes. PURPOSE To examine the relationship between salivary immunoglobulin A (s-IgA) and upper respiratory infections (URI) in a cohort of professional athletes over a prolonged period. METHODS Thirty-eight elite Americas Cup yacht racing athletes were studied over 50 wk of training. Resting, unstimulated saliva samples were collected weekly (38 h after exercise, consistent time of day, fasted) together with clinically confirmed URI, training load, and perceived fatigue rating. RESULTS s-IgA was highly variable within (coefficients of variation [CV] = 48%) and between subjects (CV = 71%). No significant correlation was found between absolute s-IgA concentration and the incidence of URI among athletes (r = 0.11). However, a significant (28%, P < 0.005) reduction in s-IgA occurred during the 3 wk before URI episodes and returned to baseline by 2 wk after a URI. When an athlete did not have, or was not recovering from URI, a s-IgA value lower than 40% of their mean healthy s-IgA concentration indicated a one in two chance of contracting an URI within 3 wk. CONCLUSION On a group basis, relative s-IgA determined a substantial proportion of the variability in weekly URI incidence. The typical decline in an individuals relative s-IgA over the 3 wk before a URI appears to precede and contribute to URI risk, with the magnitude of the decrease related to the risk of URI, independent of the absolute s-IgA concentration. These findings have important implications for athletes and coaches in identifying periods of high URI risk.

Epidemiology of injuries and illnesses in America's Cup yacht racing

Objectives: To determine the incidence and severity of injuries and illnesses incurred by a professional America’s Cup yacht racing crew during the preparation for and participation in the challenge for the 2003 America’s Cup. Methods: A prospective study design was used over 74 weeks of sailing and training. All injuries and illnesses sustained by the 35 professional male crew members requiring medical treatment were recorded, including the diagnosis, nature, location, and mechanism of injury. The volume of sailing and training were recorded, and the severity of incidents were determined by the number of days absent from both sailing and training. Results: In total, 220 injuries and 119 illnesses were recorded, with an overall incidence of 8.8 incidents/1000 sailing and training hours (injuries, 5.7; illnesses, 3.1). The upper limb was the most commonly injured body segment (40%), followed by the spine and neck (30%). The most common injuries were joint/ligament sprains (27%) and tendinopathies (20%). The incidence of injury was significantly higher in training (8.6) than sailing (2.2). The most common activity or mechanism of injury was non-specific overuse (24%), followed by impact with boat hardware (15%) and weight training (13%). “Grinders” had the highest overall injury incidence (7.7), and “bowmen” had the highest incidence of sailing injuries (3.2). Most of the illnesses were upper respiratory tract infections (40%). Conclusions: The data from this study suggest that America’s Cup crew members are at a similar risk of injury to athletes in other non-collision team sports. Prudent allocation of preventive and therapeutic resources, such as comprehensive health and medical care, well designed conditioning and nutritional programmes, and appropriate management of recovery should be adopted by America’s Cup teams in order to reduce the risk of injury and illness.

The Epidemiology and Aetiology of Injuries in Sailing

Sailors are at risk of injury and an understanding of the risks and causes of injury are important in helping to reduce their frequency and severity.Injuries are specific to the class of sailing. In elite Olympic-class sailing the incidence of injury is ∼0.2 injuries/athlete/year, with the lumbar and thoracic spine and the knee most commonly injured. Poor hiking technique and inadequate leg strength are thought to predispose the knee to injury. Injuries in novice and recreational sailing are predominantly acute in nature with contusions and abrasions typically occurring as a result of collisions with the boom or other equipment during manoeuvres. The only report of injuries in Paralympic-class sailing found a high rate of ∼100 injuries/1000 days of sailing, likely due to severe sailing conditions. The majority of injuries were chronic in nature, predominantly sprains and strains of the upper extremity. The risk of windsurfing injury ranged from 1.1 to 2.0 injuries/person/year, with the majority of injuries being acute, typically due to impact with equipment. Severe injuries are frequent, with competitive male windsurfers often admitted to hospital for treatment. Chronic lower back injuries are also common in windsurfers and may be related to prolonged lordosis (lumbar extension) of the spine while ‘pumping’ the sail. In professional big-boat sailing, America’s Cup studies have reported an incidence of ∼2.2 injuries/1000 hours of sailing, with one study reporting a higher incidence of injury during fitness training sessions (8.6 injuries/1000 hours of fitness training). The main cause of injury seems to be non-specific overuse, with joint and ligament sprains and tendinopathies being the most common. Grinders and bowmen are at greatest risk of injury, with the repetitive nature of ‘grinding’ a contributing factor. In round-the-world offshore racing, 1.5 injuries/person/round-the-world race (amateur), and 3.2 injuries/person/race (professional) have been reported, with the majority being impact injuries (e.g. contusions, lacerations, fractures and sprains). Helmsmen experience mostly upper-limb overuse injuries as a result of ‘steering’, while mastmen and bowmen are at greater risk of acute injuries. Illnesses and non-injuryrelated complaints account for a large proportion of medical conditions in these events.Sailors of all classes and abilities seem to be at risk of injury, particularly from acute impacts with equipment that might be reduced by wearing protective clothing and more ergonomic boat design. High repetition activities, such as hiking, pumping, grinding and steering, are major causes of overuse injury in experienced sailors. Informed coaching of correct technique and appropriate progression of physical and technical developments are required. Competitive sailors should undergo regular health screening with specific strengthening of high-risk muscle groups, synergists and stabilizers. The scarcity of analytical studies of sailing injuries is a major concern, and there is a need for thorough prospective studies.

Thermoregulatory demands of Elite Professional America's Cup Yacht Racing

Americas Cup yacht racing predominantly occurs during the summer months under hot and humid conditions, with athletes exposed to the environment for prolonged periods, and yet the thermoregulatory responses to competitive sailing are largely unappreciated. This study aimed to assess the thermoregulatory responses to elite professional big‐boat yacht racing, according to crew position and upwind and downwind sailing. Intestinal (Tcore) and skin temperature, fluid balance and regional sweat compositions were measured in two Americas Cup crews (n=32) during 100 min of racing. The environmental conditions were as follows: 32 °C, 52% RH and 5 m/s wind speed. Subjective race intensity was moderate. Bowmen recorded the greatest elevation in the heart rate (184 ± 10 beats/min) and Tcore (39.2 °C, P<0.01). Both heart rate and Tcore were higher during downwind sailing (P<0.001). Regional skin temperatures were significantly different according to site (P=0.05), with tibia being the lowest (33.3 ± 1.2 °C). The mean sweat loss during racing was 1.34 ± 0.58 L/h (range: 0.44–2.40 L/h), with bowmen experiencing the greatest loss of sweat (3.7 ± 0.9% of body mass). The mean fluid intake was highly correlated to sweat loss (r=0.74, P<0.001), with 72 ± 41% of sweat losses replaced. The mean sodium concentration of sweat was 27.2 ± 9.2 mmol/L (range: 12.0–43.5 mmol/L) and the total NaCl loss during sailing was 3.8 ± 2.4 g (range 0.7–10.0 g). Americas Cup sailing is a demanding sport that presents considerable challenges to thermoregulation, fluid and electrolyte balance. Certain crew roles (bowmen) present an increased risk of developing exertional heat illness, and for the majority of crew downwind sailing results in greater thermal strain than upwind sailing – which may have implications for clothing selection and boat design.

America's Cup yacht racing: Race analysis and physical characteristics of the athletes

Abstract The Americas Cup is the oldest competing trophy in sport, yet little is known of the nature and intensity of racing or the physical characteristics of the athletes. In this study, aspects of the physical demands of Americas Cup yacht racing were analysed, including the intensity of exercise and activity pattern of “grinding”. Anthropometric data were collected from 92 professional male Americas Cup sailors, and fitness data from a top-4 and a lower-7 ranking team during the 32nd Americas Cup. Over the 135 races, mean race duration was 82 min (s = 9), with 20 tacks (s = 10) and 8 gybes (s = 3) per race. Grinding bouts were 5.5 s (s = 5.4; range: 2.2–66.3) long, with 143 exercise bouts per race and an exercise-to-rest ratio of 1:6. Mean and peak heart rate was 64% and 92% of maximum for all positions, with bowmen highest (71% and 96%). Grinders were taller, heavier, and stronger than all other positions. Body fat was similar between positions (13%, s = 4). The higher-standard team was stronger and had greater strength endurance, which probably contributed to their quicker manoeuvres. Intensity of exercise was dependent on the similarity of competing boats and the role of the athlete. The short duration and intermittent nature of grinding is indicative of predominantly anaerobic energy provision.

“Sports injuries in an America's Cup yachting crew: A 4-year epidemiological study covering the 2007 challenge”– A critical commentary

The title implies that this was a 4-year study, when in fact it was conducted over a period of just 2 years and 8 months. Furthermore, data were collected during only 8 of 13 qualifying competition regattas (referred to as ‘‘Acts’’) between October 2004 and June 2007. Hence, it is unlikely that incidence rates (particularly chronic injuries) could be accurately determined or recurrent injuries correctly classified during the 2007 America’s Cup challenge. The authors write that ‘‘the classification of sports injuries used in the current study is similar to that used in other sports’’. We disagree with this statement; in particular, the classification of injury type (‘‘acute or recurrent’’) and the nature of injury (‘‘traumatic or chronic’’) are inconsistent with other sports injury epidemiology. The status of an injury can be pre-existing (which should not be included in incidence data), new or recurrent. The nature of an injury can be either acute or chronic, where an acute injury is defined as resulting from a specific, single traumatic event, and a chronic injury resulting from a gradual development of symptoms through overuse or prolonged exposure (Neville & Folland, 2009). Therefore, we suggest that the authors have mistakenly written ‘‘acute’’ where they mean ‘‘new’’ and ‘‘traumatic’’ where they mean ‘‘acute’’, hence the injury type should be either new or recurrent and the injury mechanism (commonly referred to as the nature of injury) should be either acute or chronic. This may explain why some typically acute injuries, namely an ankle sprain, three wrist ulnar collateral ligament sprains, and an elbow medial collateral ligament sprain were incorrectly classified as ‘‘overuse’’ injuries in the paper. The two knee medial collateral ligament sprains, which were not classified, should also be included as ‘‘acute’’ injuries. Some of the reporting of injury diagnosis is also inconsistent with current sports epidemiology surveillance. The most common injury diagnosis was ‘‘muscle contractures’’ (37 of 90 injuries or 41%). This term describes the sustained shortening of a muscle and is often used to describe muscle contractures in people with brain or neurological injuries. This diagnosis is not commonly reported as an injury diagnosis in athletes and it is unclear as to the exact nature of such injuries. We suggest the authors have mistaken muscle spasms or cramps for contractures. The large number of these injuries may partly explain the high proportion of recurrent and overuse injuries reported in this study (muscle contractures were predominantly classified as recurrent and overuse) and the low proportion of injuries resulting in absence from sailing (only 3%).