#1 - You should run in a way that makes you healthier and happier.
I believe that the benefits of competition and performance are the least of the benefits a person can get from learning to run pain-free. Running pain-free is a joy. It's fun. It's playful. I ran with pain for years and it wasn't a pretty thing. It began to feel obligatory. It was work.
For runners, if you go back to my aerobic development post, you'll see the scheme I generally use to build my training for a running event. The true gift of aerobic training is that you can build health and performance together with less risk of over-training.
|Running should help you get happy, happy.|
#2 - You can have too much of a good thing.
How much is too much? There will be an obvious difference between people but there's no denying the science that running really far and really fast for years and years isn't healthy. Endurance athletes have a higher incidence of cardiovascular abnormalities than the general population and I think this is because of the too far, too fast culture of endurance running. We know that a certain amount of physical activity is important for the body to function normally. Some exercise boosts your immune system while exercising to exhaustion temporarily makes you more susceptible to illness. Do this chronically and you may find yourself sick often. Some activity strengthens your body tissues, your heart, and physiologically and enzymatically makes you more efficient. Too much activity has the opposite effect, you'll become weaker, slower, mentally drained, and physiologically overtaxed.
We all know about the professional athlete who has to perform well enough to make a living. I don't really argue with their lifestyle too much because they're trying to pay bills and sometimes that can be a very stressful thing. By the time athletes get to a high-level, they usually have a first-hand understanding of what's going to happen to their bodies and their health over time if they wish to stay competitive. The key however is that the professional-level athletes tend to be privy to reality. You can expect that if you're an NFL player or a professional dancer, major injuries and surgeries are likely part of earning your paycheck. In order to be a top distance runner, you can expect that you will need to put in serious mileage and work the intensity to a significant degree. There is of course no crystal ball to the question, how much is too much? It all depends on your body and if you're listening to it you can often avoid trouble.
#3 - Preparation is everything. However your preparation should be generally sustainable.
#4 - You can't have it all, all the time.
Inherently there is nothing wrong with wanting to become a better version of yourself. There's nothing wrong with wanting to see how far you can go or how good you can be. It's just that there will be a cost.
Sometimes it's okay to push. Sometimes it's okay to really go for it. In preparation for the Spartan World Championships I trained well within my capacity but when it came time to compete, all bets were off. I went all out and did things in the race I would never do in training. For months I trained sustainably, no injury or illness, so that on event day I could take more risk. This is what I recommend to other non-sponsored, non-multi-million dollar athletes- train smart and sustainable, and if you really want to take a risk, save it for the competition.
Runner #1 just wants to have fun. This is totes awesome-sauce, fine and dandy. This runner will train sustainably and enjoy their events in a sustainable way as well. They'll be able to participate in many events on their calendar year, for years and years, because they aren't wrecking their body. They will enjoy the health and social benefits and probably live forever.
Runner #2 wants a challenge but also wants to maintain physical activity into old age without serious pain, health problems, or orthopedic surgeries. This runner should train sustainably and compete hard once in awhile ensuring full recovery between difficult events. This runner wants the physical challenges but within reason, they aren't getting a retirement out of this.
Runner #3 wants to be an Olympian and set world records earning multi-million dollar sponsorships. They will sacrifice long-term health for short-term gain but in their heart it may be worth it to be the best in the country or the world.
Lots of heavy training and competing without adequate recovery isn't healthy (especially when done for years). It's possible to see a temporary improvement in performance or a few good seasons but it is very rarely sustainable for a career. I don't recommend it unless your goal involves making lots of money so you never have to work again. When we are thoughtful about the way we train, we can enjoy great experiences, enhance our health, and avoid permanent damage to a great extent. We can be old and not needing walkers and canes. We can play until the day we die.