Hamstring injuries are particularly debilitating and can easily take an athlete out for a whole season.
A recent study published in the American Journal of Sports Medicine (1) looked at hamstring injuries in NFL players over a 10 year period.
51.3% of the hamstring injuries occurred during the 7 weeks of training preceding the season start.
Pre-season training is notorious for hammering athletes hard during training camps and during athlete assessments. This strategy is opposite to the proven long term progression where intensity and total work loads are increased incrementally as an athlete demonstrated adaptation.
I believe we're still trapped into believing the go hard or go home hyperbole. It's true that athlete's can't achieve maximum performance without maximally intensive training, but it's also true that the real potential of athletes is brought out over very long periods of conservative increases in training loads.
We've all heard athletes boasting about how stiff and sore they are after hard workouts, and indeed some athletes feel a tremendous sense of accomplishment if they barf at a workout; proving that they truly worked as hard as possible.
Not really.. barfing is a result of abdominal distress in this case. Vomiting is not measure of muscle performance, efficiency of movement, or good tactical skill.
Want to prevent hamstring injuries? Assess the function of all the muscles from the hips down, fix any problems found, then gradually increase training loads over long periods. According to this study, avoiding entering pre-season training camps unprepared would be a good idea.
On the coaching side, if we know athlete's are at a high risk of injury during pre-season training, careful thought as to how to proceed with pre-season training loads might help reduce injuries.
(1) Hamstring Muscle Strains in Professional Football Players