Here are past tips: here, here , here , here, here, here and here.
FAST AND FUN—It’s a state of mind
Why is running faster a good thing? Short and fast segments not only help you run faster in races. If you run a few faster segments each week you can improve your running efficiency while receiving a better attitude boost.
How long should you be running before you add some faster running in? After 2-3 months of regular running some short accelerations can be added with minimal risk of aches and pains.
Is it possible that running fast can actually be fun? Yes. The secret is be creative and limit the length of the fast segment at first.
How often should you run fast? Playful speed can be done once or twice a week.
Four Faster, Fun Workouts
1. Speed play that you can do on your own. ACCELERATE AND GLIDE. After an easy 10 minute warmup of slow running, pick up the pace for 10 steps, then coast off the momentum for 10-20 steps. Don't be obsessed about the number of steps as this is just a guideline. Don't sprint--be playful. Gradually pick up the pace, and then glide back down to a jog. Repeat 2-3 times on your first attempt, and take a one minute walk break. Each week you could increase the number of accelerations as you wish, with a recommended walk break of 1-2 minutes between each.
1. Speed play you can do with one friend—CHASE game. After an easy 5 minute jog together, one person takes the lead. As the leader changes the pace (speeding up, then slowing down, speeding up) the follower tries to stay close but not pass. After 3-5 minutes, take a 1-2 minute walk break and repeat with the other runner leading. Repeat as many times as desired.
2. Speed play you can do with two friends—SURPRISE game. Following the same format as game 1, the follower tries to surprise the leader by passing gently but quickly. While there should be no sprinting, it is OK to run fast for 10-30 steps to pass.
3. A speed play workout you can do with three or more friends—INDIAN RUNNING. The group is running single file for a minute or two at an easy pace. Then, the last runner, passes all of the other runners and takes the lead for a minute or two. The current leader sets the pace, and takes a walk break. When the running resumes, the last runner starts to move to the front. Each runner gets to take the lead at least once in this game.