Have you ever trained hard just to discover that your fitness - or speed - doesn't seem to be improving? If so, try these things to jumpstart it:
1. Completely change your routine. If you've been doing one kind of strength training, such as machines, switch to completely different exercises with either body weight or dead weights. If you've never done weight training, start. If you've been doing lots, maybe you're not giving your body enough time to recover/repair. Cut back to just two good, solid, all-body workouts per week.
2. If you've been doing lots of speed work, completely stop all traditional speed work and switch to hill work and/or fartleks.
3. If you've been racing and training for short distances, such as 5k's, let that go for a while and switch your effort to a distance event such as a half; then, go back to your 5k emphasis next season. Or do the opposite if you've been focused on half marathons or longer.
4. If you haven't been doing any biking or spinning, start. That can make a huge difference in a hurry. Emphasize high cadence rather than pushing a high gear.
5. Improve your running form. Get someone to shoot a video of you running. It's amazing how inaccurate self awareness is. Most people are shocked when they see themselves run. Then, watch the online running form and gait analysis videos in the 'Resources' section of this site. If you'd like, send me the video and I'll analyze it. Then we can do a phone conference.
Of course, arranging a phone conference with me is always an option, whether you send me a video or not. If your issue is that you are on a plateau, then I call the conference an intervention. I'll even go so far as to give you a moneyback guarantee. I'll analyze everything you are doing and revamp your training.
Then, sit back and look forward to happier, faster times.