Well… what kind of “damage” are we talking about?
Direct Impacts to the Trail.
Let’s first consider the most obvious type of physical impact to the environment – direct trail damage due to foot traffic. I don’t see any cause for concern here, as the physical damage from an individual racer won’t be greater than a single runner out for a training run or someone out for a hike. Races simply bring more people to the trail on a particular day, just as hiking clubs, scouting troops, large family hikes and any other organized group outing would do. So unless we’re willing to impose daily usage caps (on all users) on our trails, racing shouldn’t be viewed as unnecessarily damaging.
Whenever there’s a genuine risk to the physical integrity of the trail (such as very muddy conditions after heavy rains), the responsible land managers always have the option to close the trail – to everyone. We trail runners probably shouldn’t get any special considerations in this regard, but we shouldn’t be treated worse than other trail users.
Negative Impacts to the Surrounding Environment.
What about the second level of damage? I consider this type of damage to consist primarily of trash left on the trails and damage to the surrounding infrastructure. I think this concern can be easily dealt with – racers and their supporters just need to follow the rules to avoid negative impacts.
Litter is probably the issue that comes up most often, although I have to say that in my experience of running trail races I’ve never noticed this to be a significant problem (even though I’m often running behind most of the other racers). I suppose the issue isn’t whether trash ever falls to the ground during a race – after all, wrappers will sometimes fall out of a person’s pockets or backpack, even when they’re just out for a hike.
The real issue is how long that trash stays on the ground. Most race organizations do a great job at sweeping the course the next day, and they pick up any telltale trash when they’re removing flagging. So I’d suggest that any evaluation of this type of environmental damage of a race be done a day or two after it’s done. If after the cleanup it’s not readily apparent that an event occurred just a couple days prior, then I say “no harm, no foul.”
When it comes to the other trail infrastructure, we all just need to behave as we would if we were a non-racing trail user. Use the established toilet facilities or porta-potties, and respect the other facilities (and their limitations) at the start/finish area. Paying a race fee doesn’t entitle a racer to be an inconsiderate slob.
The “Environment” Includes Other Trail Users.
The issue we should probably be most concerned with is the broader concept of “damage.” Our trail “environment” includes other trail users, and we need to remember that participating in a trail race doesn’t give us the right to act like jerks.
Don’t park in “no parking” areas, for example, and use whatever shuttle and carpooling options are available. If the race is long and you have a crew or other supporters, then make sure they’re following whatever rules and guidelines the race director has put in place. Chances are the RD knows a lot more about local customs, expectations and sensitivities than we do, so heed their guidance.
Furthermore, we should always remind ourselves that trails are rarely closed for races, so we’re probably going to encounter non-racers along the way. The issue is how we’re going to act towards those other trail users, and again I think the solution is straightforward. Just consider how you’d behave during a training run on a popular trail on a sunny Saturday afternoon. Would you barrel down the trail, yelling “heads up” in an effort to force a clear a path in front of you, refusing to slow down or share space or ever step off the trail to let others pass? Probably not.
So we shouldn’t act differently when we’re racing on those same trails. The fact that we paid our entry fees doesn’t give us the right to exclude or prevent others from using the same trails according to the normal rules of trail etiquette. If you want your fee to buy you a closed course, and you don’t want to share space, then perhaps you’d be better off racing on the roads.
At the end of the day, it’s not the races that have the responsibility of good trail behavior, it’s us racers.