Use a slight incline.
Set the treadmill inclination to 1% to 2%. Since there's no wind resistance indoors, a gentle uphill better simulates outdoor running. Of course, if you're just getting started with running, it's fine to leave the incline at 0% until you build up your fitness.
Don't make it too steep.
At the same time, don't set the incline too steep (more than 7%) -- this may lead to Achilles tendon or calf injuries. Also, don't run at an incline of more than 2% for your entire run.
Don't hold onto the handrail or console.
Some people assume that they need to hold onto the handrails when walking or running on a treadmill. The handrails are only there to help you safely get onto and off of the treadmill. When running on the treadmill, practice proper upper body form by keeping your arms at a 90 degree angle, just as you would if you were running outside.
Make sure you warm up.
Run or walk at a slow, easy pace for 5-10 minutes. It's tempting to just jump on the treadmill and start your workout, but you should allow time for a warm up.
Don't forget your cool down.
It's also easy to hop off the treadmill when your workout is done and your heart rate is elevated. Spend 5 minutes doing a slow jog or walk at the end of your run and allow your heart rate to go below 100 bpm before you get off. Cooling down will help prevent dizziness or the feeling that you're still moving when you step off the treadmill.
Don't lean forward.
Make sure to keep your body upright. It's not necessary to lean forward because the treadmill pulls your feet backward. You need to pull your feet from the belt before they are driven away by the belt.
Pay attention to your stride.
Keep your stride quick and short to help minimize the impact transferred to your legs. Try to maintain a mid-foot strike to make sure you're not heel striking and sending shock to your knees. You may need to exaggerate the heel lift because the lack of forward momentum means your feet won't be moving in a circular path.
Work on improving your stride count.
The more steps you take per minute, the more efficiently you'll run. Elite runners run about 180 steps per minute. Determine your stride count by counting how often one foot hits the belt in a minute and then doubling that number. Try to improve your stride count during your run by focusing on taking shorter, quicker strides and keeping your feet close to the belt. This exercise will help you deal with boredom on the treadmill and even improve your outdoor running.
Listen to music.
Although using headphones while running outside is not safe, listening to music on the treadmill can be a great way to combat boredom and run longer. Choose motivating songs and create a playlist for your workout -– it will help prevent you from continually checking the clock to see how much more you have to go.
More: Beat Boredom on the Treadmill
Visualize a route.
Another trick to pass the time on a treadmill is to visualize an outdoor route that you frequently drive or run. Picture yourself running along and imagine the buildings and other landmarks you'd pass along the way. Change the incline setting at the time you'd be heading up a hill.
Don't forget to hydrate.
You can lose even more water running on a treadmill then you would if you were running outside, since there's little air resistance to help to keep you cool. Keep a bottle of water within easy reach.
Don't look down.
I know it's hard not to continually look to see how much time or distance you have left, but if you're looking down, your running form will suffer. Don’t stare at your feet either. You're likely to run hunched over, which could lead to back and neck pain. Looking straight ahead is the safest way to run, whether you're on the treadmill or running outside.