If there's ever a time to reward yourself for going that extra mile, finishing a marathon is probably it.

If you're a beer drinker, you may want to celebrate with a beer, but you may also be wondering if it's the best thing to be feeding your body after a long run.

"Running a marathon is hard work and definitely a cause for celebration," says Kim Lowry, dietitian at Houston Methodist and experienced marathon runner. "Having a post-race beer is totally fine — after you've first given your body the nutrition it needs to recover."

Before you have a beer, focus on recovery

After the race, rehydrating and consuming carbohydrates and protein should be your first priority.

Within an hour of finishing the race, Lowry recommends consuming:

• 60-80 gm of carbohydrates
• 30-40 gm of protein

Carbohydrates will help replenish your muscle's energy stores, while protein will help kick-start muscle repair.

"For instance, you could have a chocolate milk or protein shake," says Lowry.

When it comes to rehydrating, Lowry recommends drinking half of your body weight in ounces over the 24 hours that follow the race.

And if you're thinking that a cold beer might be a good way to rehydrate (there's water in there, right?) or that it counts towards your carb goals — think again.

"First of all, alcohol itself is dehydrating," explains Lowry. "And while many people may think that beer is full of those carbs you need during recovery, it really isn't."

Beer can't actually help you carb-load

Unfortunately, beer is not a replacement for the post-race recovery snacks Lowry recommends above.

"Only about one-third of the calories in a 150-calorie beer comes from carbs," explains Lowry. "The rest are calories that come from the alcohol itself — which is metabolized and stored as fat."

This means that most of the calories in your post-race beer aren't actually helpful in the post-race recovery process. But, Lowry isn't saying you have to skip that post-race beer you may want, either.

"In terms of celebrating with a beer after the race, I say go for it. You just finished a marathon!" Lowry says. "But first, make sure you start on the recovery process. Get some fluids, get some carbs and protein — and then treat yourself to that cold, tasty beer."