5. Alternate hard and easy
If you don't push yourself, you'll never develop the ability to run farther or faster. But if you don't rest enough, you'll burn out or get injured. Follow speed sessions or long runs with an easy run or rest day, and every few weeks cut back your mileage by 20 percent. These recovery periods allow your body to repair and rebuild damaged muscle tissue, thereby helping you get stronger and more resistant to fatigue at faster paces and longer distances.6. Remember to cross-train
When you run, your muscles, joints, and connective tissues absorb a lot of shock. Cross-training gives your body a break from the pounding while maintaining your cardiovascular fitness. Yoga, Pilates, and strength training promote recovery, build muscle, and develop a strong upper body. Swimming, cycling, elliptical training, and rowing improve your aerobic fitness (for more ideas, try these 4 Workouts Borrowed From Other Sports).
Go too hard on easy days and you won't have the energy for speed sessions and long runs. Go too slow during hard workouts and you won't push your fitness to the next level. Use pace, heart rate, or the talk test to ensure you're working out at the right intensity and reaping the intended benefit of every run.
8. Turn it up
Even marathoners looking simply to finish should do speedwork. Running fast builds cardiovascular strength by forcing your heart to work harder to deliver oxygen to your leg muscles, which, in turn, get stronger and more efficient at extracting oxygen from your blood. Speed sessions raise your metabolism, increasing calorie burn even after your workout. Turning your legs over at a quicker rate also sheds sloppiness in your stride--you'll run more efficiently and it will take less effort to run fast.
9. Run at race pace
Spend time practicing your goal speed during training and it will feel like your body's natural rhythm come race day. Mentally, logging dozens of miles at race pace will help you feel more confident when the starting gun goes off.
10. Trust the taper
In the final three weeks before race day, drop your weekly mileage by 25 to 50 percent, but maintain the intensity of race-pace runs and speed-work. Many runners fret that they'll lose fitness. But a 2010 study by researchers at Ball State University found that runners who maintained speedwork but dropped their weekly mileage by 25 percent three weeks before race day lost no cardiovascular fitness, gained muscle strength, and improved their race times.race.