Assuming you are starting from scratch, gradually building up your running program is key to success and avoiding injury. The general rule of thumb is to add no more than 10% to your weekly mileage. So, if you are running 20 miles per week, you should not add more than 2 miles per week.
Starting out, you should run 3-4 times per week, with each run being no longer than 30 minutes. As you gradually build up your mileage, you can add 5-10 minutes to each run. Once you are running for 30-60 minutes, you can start to focus on your pace and begin doing speed work.
For new runners, it is best to run at a comfortable pace where you can still carry on a conversation. As you get more comfortable with running, you can start to pick up the pace and challenge yourself.
It is important to listen to your body when starting a running program. If you are feeling pain or discomfort, slow down or take a break. Pushing through pain can lead to injury.
Overall, gradually building up your mileage and listening to your body is key when starting a running program. By following these conditioning research guidelines, you will be on your way to becoming a successful runner.