A horse race is a sporting event in which humans compete against horses. The rules of a race vary across countries, but most have similar basic principles. Most races are flat races, which means they are run on a dirt or turf track with no hills. The length of a race can range from less than two miles to four or more, but most are short races that require fast acceleration. Longer races are known as “routes” in the United States and as “staying races” in Europe, and they require stamina.

There are a number of different categories of horse races, with the highest-level events being called “stakes” races. In order to be considered for a stakes race, horses must meet certain criteria, such as age, sex, and breeding. These races are able to attract the best horses in the industry, and winning one can be extremely lucrative.

The first organized horse race in North America was held in 1664, with colonists racing Thoroughbreds over a two-mile course. Stamina was the hallmark of excellence for American Thoroughbreds until after the Civil War, when speed became king.

While the sport of horse racing may seem glamorous to spectators sipping mint juleps, behind the scenes is a world of injuries, drug abuse, and gruesome breakdowns. Pushed to the limit, horses are forced to sprint-often under the threat of whips and even illegal electric shock devices-at speeds so fast that many will bleed from their lungs, a condition called exercise-induced pulmonary hemorrhage. To combat this, most are given cocktails of legal and illegal drugs designed to mask injury and enhance performance.

Trainers prepare their horses for race day by following a schedule of races that is published in a document called the condition book. The condition book includes the scheduled dates for each race at a track, as well as the distances and class levels of those races. A trainer can then determine which horses to enter and develop training programs for each horse based on this information.

The most common type of horse race is a stakes race, which requires that a horse meet certain qualifications to be entered. To qualify for a stakes race, a horse must be a particular age and sex and have won a specific amount of money in previous races. A horse must also meet the entry requirements of the race in which it will compete, including a minimum amount of time since its last race. If a horse fails to qualify for a race, it is often eligible for another race in its class that will be considered a substitute. This can be a frustrating situation for horses, as it may require them to change their travel plans and make additional expenses.