0 How to Increase Running Speed

As a runner, especially for runners who compete in races and competitions, being able to maintain a good speed is crucial. Faster running can improve race time and puts you at a better advantage against competitors.
There are a few things you can do to increase running speed, which may mean that you make dramatic changes to your routine or just small tweaks here and there.

1. Long Distance Running

One of the things that will help improve running speed is to go on a long run once or twice a week. Even though you will be running slower than you are capable of, running for long distances will slowly build up endurance. Improving your endurance will help to improve the distance you can run, and the more you do these runs will mean you will be able to sustain a certain speed for a longer period of time. So over time your overall speed will increase because your body has become more resilient to running and will become less fatigued.
A post that I have recently written, that you may want to read, concerns stamina: How to Improve Stamina.

2. Sprinting

It's not wise to sprint in a long distance race, except for right at the end, but by then you're tired and won't be able to reach your fastest speed. In order to be used to running at your fastest speed you will need to run at your fastest speed. The more you do this the more your muscles will grow used to moving your joints quickly and propelling your body forwards quickly.
Sprinting exercises are good for this. For example running 4x100m as fast as you can (10 seconds rest in between), or interval training where you run 3-5 minutes of fast paced running and then 3-5 minutes normal pace running.

3. Stretch Regularly

Stretching regularly is important, especially for those of you who exercise often. Stretching will help prevent your joints and muscles from becoming tight which can limit movement. So, if you stretch your range of movement will increase, your strides may become larger than usual and your muscles will be able to cope better with the tension they are put under.
If you want to read more about why you should start stretching, I'll redirect you to this previous post of mine: Benefits of Stretching.

4. Strengthen Your Legs

Your legs are what you use to run and are what support the rest of your body. Strong legs are going to be able to support more weight, so supporting the rest of your body during runs will become easier. Regular running and walking will strengthen your legs over time, but doing other things such as: hill-running, squats, using leg-strengthening machines (at gym), will help to strengthen them quicker, and your explosive power will become better - which will mean better starts.
If you specifically decide to devote a session to strengthening your legs, don't do it again the day after - your legs will need time to recover from the workout and become slightly stronger.  

5. Shoes Specifically for Speed Training

This may sound like a bit too much but is actually something that a lot of competitive runners do, in fact some have multiple pairs of shoes for different training exercises and sessions.
I wouldn't really recommend doing this unless you are really serious about running and are training for something, otherwise for the average runner it's just a waste of your money.