As posted on Runner’s World.
By Ed Eyestone

I once asked a colleague who has coached many runners to collegiate and Olympic glory what he considered the proper mileage totals to succeed in distances from the 5K to the marathon. “That’s easy,” he said. “You want to run as few miles as you can and still win.”

Runners too often get caught in the mileage trap, thinking more is better. The truth is, more mileage is better only up to the point where you can achieve your potential. After that, each additional mile only increases your injury risk. The following six rules informed the mileage ranges below and can help you find your magic number.

Rule 1: The longer the race, the higher the mileage. Not surprisingly, a marathoner needs to run more than a 5K specialist.

Rule 2: Mileage requirements increase as performance goals increase. If your goal is simply to finish a race, you can run fewer miles than if your goal is to finish with a fast time.

Rule 3: Some miles count more than others. When your weekly miles include tough track workouts, tempo runs, and short repeats, they’re harder to recover from than if you do the same volume of easy aerobic running. So when you add quality workouts, decrease your total mileage slightly to make up for the added stress.

Rule 4: Some miles count more than others (part two). The farther away your miles are from race pace, the less they will help your racing performance. The principle of specificity means that you become good at what you practice. If you mostly run long, slow miles, you will become proficient at running long, slow miles. My ultramarathoner friends often go on four- and five-hour slow runs, which prepare them for 50-mile-plus races but do little for their ability to smoke a fast 5K.

Rule 5: Allow for adaptation when increasing mileage. To avoid injury when upping your mileage, you need to take it slow and allow your body time to adapt to the increased workload. In general, you can add a mile for every run you do per week, provided you then run at least two weeks at the new level before advancing again. If you run six times a week, for example, you can up your weekly mileage by six miles. Then stay at that higher level for two weeks before adding another six.

Rule 6: A healthy runner beats an injured runner every time. I’ve applied my colleague’s theory of running the least amount of miles and still winning to one of my often-injured college athletes. This runner consistently got hurt whenever he ran more than 80 miles a week, even though that’s a modest total for an elite 10-K runner. But when he capped his mileage just below 80 miles, he was able to complete the season healthy and win a national championship. High mileage totals do you no good if they put you on the sideline instead of the starting line.

Target Totals:
So exactly how many more miles does a marathoner need to log per week than a 10K or 5K runner? Here are some suggested weekly totals by event for elites versus the rest of us: