OSUsushichic;877952; said:
Speed work really helps. There are different ways to go about this, but just getting your heart rate up for a few minutes and then returning to your normal speed can go a long way. They're called Fartleks.
There is a ton of literature on it, but here's one:
Active.com - Fartlek training can boost your running speed, endurance
Put together a good music mix when doing speed work (mix fast songs with slower songs). It really helps!
Co-sign. Other popular speed workouts involve track workouts (if you have access to one) by doing repeat 400's, 800's, and/or 1600's, depending on what you are attempting to achieve:
400 - These will help improve foot speed over "shorter" distances. Every good for shorter races (5K and under). If you are shooting for 8:00 pace (which would be 2:00 per 400) attempt to run your repeats in 1:45-1:50 but not any faster. Start out with 4-400's with a 3-5 minute rest between each one. Be sure not to cut the rest time short!
800 - Similar to the 400's but are also used for the mid races (5 mile, 10K) for speed. Using the 8:00 pace example (4:00 per 800) shoot for 3:45-3:50 per 800. Start out with 3-800's with a 5-6 minute rest between each repeat. Again, don't cut the rest time short!
1600 - These will help hone in the pace you would like to run... I've never trained for a marathon but if I did these would be my "speed" workout of choice. For an 8:00 pace goal attempt to run your repeats in 7:45-7:50. Start out with 2-3 of these, depending on your condition, with a 9-10 minute break in between.
If you are training for a 5K or 10K and want to work on pure leg turnover do 100m or 200m repeats in a fartlek fashion... run a 100/200 hard, jog or walk a 100/200. Repeat 8-10 times.
In general, distance speed workouts should be mostly about conditioning your body to run a quicker pace. Unlike sprinting speed workouts, distance speed workouts should be done slightly faster than the target pace, not 80-100% of your quickest speed.