Are treadmills really as effective as running outdoors?

To answer your questions, treadmill running and road running are not quite the same. Running on the treadmill is easier than running outdoors, for a variety of reasons. One reason is that the treadmill belt assists leg turnover, making it easier to run faster. So most runners find that their pace on the treadmill doesn’t correlate to their road pace. Also, some of the soft tissue conditioning or “hardening” that occurs with road running does not occur with treadmill running because the plate or base on the treadmill "gives" more than road surfaces. And, obviously there are no weather conditions to deal with when running indoors.

 

However, the treadmill can be a great training tool. Because treadmill running is easier, use it for speed work. Use the treadmill to help you run faster by speeding up the pace for short intervals and then slow it down for recovery intervals. This is a very convenient way to get in some speed work or tempo runs in a controlled setting.
 

 

Run outdoors two or three days a week, with one day designated as your long run day and one or two other runs of shorter distance. This will provide the mileage, the conditioning, and the weather acclimatization you need for your half-marathon. Include the treadmill one or two days a week for speed work or tempo runs. This gives you three to five days of running. Continue with your cross-training one or two days a week, focusing on muscular strength and endurance.  Add some stretching exercises to promote muscular flexibility and you have a very well-rounded training plan.