The menstrual cycle and sport performance.

https://www.europeanurology.com/article/S0302-2838(04)00562-7/pdf/the-vicious-cycling-bicycling-related-urogenital-disorders

The Vicious Cycling: Bicycling Related Urogenital Disorders

During endurance exercise, about 75% of the energy produced from metabolism is in the form of heat, which cannot accumulate. The remaining 25% of energy available can be used for movement. As running pace increases, the rate of heat production increases. Also, the larger one's body mass, the greater the heat production at a particular pace. Sweat evaporation provides the primary cooling mechanism for the body, and for this reason athletes are encouraged to drink fluids to ensure continued fluid availability for evaporation and circulatory flow to the tissues. Elite level runners could be in danger of heat illness if they race too quickly in hot/humid conditions and may collapse at the end of their event. Most marathon races are scheduled at cooler times of the year or day, however, so that heat loss to the environment is adequate. Typically, this postrace collapse is due simply to postural hypotension from decreased skeletal muscle massage of the venous return circulation to the heart on stopping. Elite athletes manage adequate hydration by ingesting about 200-800 mL/hour, and such collapse is rare. Athletes "back in the pack" are moving at a much slower pace, however, with heat accumulation unlikely and drinking much easier to manage. They are often urged to drink "as much as tolerable," ostensibly to prevent dehydration from their hours out on the race course. Excessive drinking among these participants can lead to hyponatremia severe enough to cause fatalities. A more reasonable approach is to urge these participants not to drink as much as possible but to drink ad libitum (according to the dictates of thirst) no more than 400-800 mL/hour.

Fluid replacement during marathon running.

ObjectiveTo establish relationships between body weight changes and serum sodium during and after an Ironman Triathlon, and postrace fluid status and rectal temperature, including the incidence of hyponatremia.DesignDescriptive research.SettingThe 2000 South African Ironman Triathlon, in which each

Weight Changes, Sodium Levels, and Performance in the South African Ironman Triathlon

Bicycle riding is a popular form of recreation among persons of all ages, and related injuries cause significant morbidity and mortality Most injuries occur in males and are associated with riding at high speed; most serious injuries and fatalities result from collisions with motor vehicles Although superficial soft tissue injuries and musculoskeletal trauma are the most common injuries, head injuries are responsible for most fatalities and long-term disabilities Overuse injuries may contribute to a variety of musculoskeletal complaints, compression neuropathies, perineal and genital complaints Physicians treating such patients should consider medical factors, as well as suggest adjusting various components of the bicycle, such as the seat height and handlebars Encouraging bicycle riders to wear helmets is key to preventing injuries; protective clothing and equipment, and general safety advice also may offer some protection

Bicycle-related injuries.

This article reviews the available literature regarding injuries in off-road bicyclists. Recent progress in injury research has allowed the description of several patterns of injury in this sport. Mountain biking remains popular, particularly among young males, although sales and participation figures have decreased in the last several years. Competition in downhill racing has increased, while cross-country racing has decreased somewhat in popularity. Recreational riders comprise the largest segment of participants, but little is known about the demographics and injury epidemiology of noncompetitive mountain cyclists. Most mountain bikers participating in surveys reported a history of previous injuries, but prospective studies conducted at mountain bike races have found injury rates of <1%. The most common mechanism of injury involves a forward fall over the handlebars, usually while riding downhill, which can result in direct trauma to the head, torso and upper extremities. A variety of factors can be associated with this type of fall, including trail surface irregularities, mechanical failures and loss of control. In mountain bike racing the risk of injury may be higher for women than men. Minor injuries such as abrasions and contusions occur frequently, but are usually of little consequence. Fractures usually involve the torso or upper extremities, and shoulder injuries are common. Head and face injuries are not always prevented by current helmet designs. Fatal injuries are rare but have been reported. Improvements in safety equipment, rider training and racecourse design are suggested injury prevention measures. The authors encourage continued research in this sport.

Mountain biking injuries: an update

https://www.wemjournal.org/article/S1080-6032(02)70583-8/pdf

Mechanisms of injury in competitive off-road bicycling.

A descriptive study was conducted to investigate injuries sustained at a major off-road bicycling race at Mammoth Mountain, California, July 6 to 10, 1994. A total of 4027 individual starts in five events during the race were reported. Overall, the total number of competitors in the 5 events was 3624, with some cyclists participating in multiple events. Injuries were considered significant if they occurred during competition and prevented the rider from completing the event. Sixteen cyclists had injuries that met these criteria for an overall injury rate of 0.40%. These 16 cyclists had 44 injuries. Abrasions were the most common injury, followed by contusions, lacerations, fractures, and concussions. The mean injury severity score was 3.0 (range, 1 to 5) with 81.2% of the injuries resulting from cyclists going downhill. Injuries were more severe when the riders were thrown from the bicycles (P = 0.03). We observed different mechanisms of injury in various events, suggesting that the risk factors for sustaining a traumatic injury may vary according to the type of competition involved.

Acute Injuries in Off-Road Bicycle Racing

Off-road bicycles, commonly called ‘mountain bikes’, have become increasingly popular worldwide since their introduction in the western US in the late 1970s. This popularity is partly because these vehicles can be ridden on a wide variety of terrain which is not accessible to other types of bicycle. Although early versions were rather crude, off-road bicycles today typically include high strength, lightweight frames with a wide array of available suspension and braking systems. Virtually all aspects of the technology continue to evolve, including components and protective equipment. As the popularity of off-road cycling has increased, so too has the interest and level of participation in the competitive aspects of the sport. Currently, 2 organisations — the National Off-Road Bicycle Association (NORBA) and the Union Cycliste Internationale (UCI) — sponsor the major events within the US and around the world. To date, the majority of studies have been descriptive in nature, with data collected via self-report, questionnaire formats. Only 1 prospective study has been reported thus far, which surveyed a major international competition held in the US in 1994. Injury rates calculated on the basis of injuries per ride or event in competitive venues have been reported, ranging from 0.2 to 0.39% compared with 0.30% for recreational participants. Retrospective data collected from recreational and competitive riders indicate that from 20 to 88% of those surveyed reported having sustained an injury during the previous year of participation. The majority of injuries appear to be acute, traumatic episodes involving the extremities, with contusions and abrasions being the most common. In general, the incidence of more severe injuries such as dislocations, fractures and concussions is low. Comparisons between road and off-road cycling events indicate that off-road cyclists sustain more fractures, dislocations and concussions than their road-event counterparts. Future research should incorporate epidemiological methods of data collection to determine the relationships between vehicle design, terrain and safety equipment and riding-related accidents. Further, those engaged in such research should attempt to set a standard definition for injury.

Off-road cycling injuries. An overview

OBJECTIVE To evaluate injury rates and patterns in off-road bicycle racing, and to compare the findings in male and female cyclists. SETTING The study was conducted from 1994-2001 at a large off-road bicycling competition held for 4 days each summer at Mammoth Mountain, California. DESIGN Injured cyclists were evaluated at the first aid station or at the local hospital. Registration data were used to estimate the number of male and female competitors in each race. PARTICIPANTS Cyclists who sustained an injury during a race and were unable to finish the race due to the injury were included in the study. 22 female subjects and 71 male subjects met the inclusion criteria during the 8-year study period. There were a total of 20,769 race participants during the study period. MAIN OUTCOME MEASURES Injuries were categorized, and injury rates were calculated. RESULTS The overall injury rate during the study period was 0.77% (22/2,869) for women versus 0.40% (71/17,900) for men (p = 0.01). Fractures were sustained by 45.5% (10/22) of female subjects versus 21.1% (15/71) of male subjects (p = 0.03). Odds ratios indicate that overall, women were 1.94 times more likely than men to sustain an injury and 4.17 times more likely to sustain a fracture. CONCLUSIONS These data suggest that although participation in this sport is higher among men, the risk of injury is greater for women.

Robert L. Kronisch

Papers

Mountain biking injuries: an update

Mechanisms of injury in competitive off-road bicycling.

Acute Injuries in Off-Road Bicycle Racing

Off-road cycling injuries. An overview

Gender differences in acute mountain bike racing injuries.