What kind of running experience/mileage should I have before training for a marathon?
You should be able to run at least 15-25 miles per week. If you have a consistent history of fitness training, even though it may be with another activity like cycling or aerobics, this will augment a lower running mileage. You should also have participated in a couple 10-k or 5-k races and enjoyed the experience of racing.What are the most common mistakes runners make when training for the marathon?
Increase your training mileage/time by no more than 10-20 % weekly. For example, if you’re currently running 20 miles per week, increase your total weekly mileage by no more than 2-4 miles the next week. A periodic long run is part of race preparation, but you should reduce other training components or introduce a rest day. Gradually introduce speed or hill work. Change only one training component at a time. For example, if you’ve decided to begin some hill work (intensity), don’t increase your running mileage the same week.
This is a sure way to end up watching other people run the marathon.
You should have at least one rest day each week. You should also have periodic light training weeks (every 4-6 weeks), particularly after a race or heavy week.
"I don’t need to strengthen my legs because running does that". Not true. Due to the repetitive nature of running, muscle imbalances which cause injuries are very common. Tight or weak muscles should be addressed with a specific conditioning program to avoid "breakdown" from the chronic stress of marathon training.
Train in a supportive, well-fitting pair of running shoes, with ample room in the toebox. Depending on your weight and running surface, you should replace your running shoes every 250-500 miles. The sole of your shoe is made with extremely durable rubber which may still look good even if the midsole is no longer providing cushioning or support. Remember that shoes wear out before they look worn out. If you set your shoes on a level surface and they tilt in or out, they’ve begun to break down and will no longer support you. Nagging foot, knee, back or hip pain may be another signal that you need new footwear.
You can do up to 20% of your mileage in activities like cycling, deep water running, swimming, stair climbing etc. to reduce wear and tear on your body.
Don’t beat yourself into the ground by training with friends who have a different fitness level, longer history of running, longer stride or much faster pace.