Not at all -- there are alternatives that also strengthen leg muscles and lead to improvements in running performance.
Most treadmills can be elevated up to 10% or 11%, which is an ideal hill simulator. On less expensive machines you may have to change inclines and speeds yourself.
Others give you a choice of preprogrammed intervals and accept workouts that you can choose yourself and enter into memory. You might try a 10-minute warm-up jog, then one to two minutes at 10% incline at about 10K race pace, followed by four or five minutes of level jogging for recovery.
Begin with two hill repeats and increase by two per week until you reach between 12 and 20 repeats.
Bike or step intervals
Many bike or step machines also come with interval programs, and let you add your own interval programs.
You can warm up for at least 10 minutes at moderate intensity, then begin bursts of one to two minutes at high intensity followed by four or five minutes' recovery at low intensity.
Begin with two repeats and increase by two per week until you reach a goal of 12 to 20 repeats.
If you use a bike machine you can sit on the saddle for the low-intensity periods, but stand up on the pedals for the high-intensity intervals.
The two machines can be similar in effect, because the sensation on most step machines is similar to standing on the pedals of a bike machine, not like climbing stairs.
In addition to high-intensity intervals, some machines have fartlek-simulating programs, in which the intensity varies widely for different periods. One popular brand of stepper calls this the "roller coaster" workout.
If you don't have access to a machine, go to your local track, ball field or stadium and head for the bleachers. You can get a good step workout here
Warm up for at least 10 minutes to get used to the rhythm, then run up hard and walk down slowly for recovery. You can build sets of repetitions to simulate the kind of interval program described above.
An all-round weightlifting program makes runners more efficient, according to a recent study. If you don't have time or inclination to include a comprehensive set of exercises, the most effective upper-leg muscles exercises are squats, lunges, and straight leg lifts.
A few pointers: For squats, stop when your thighs are parallel to the ground, and keep your knees over your feet. For lunges, stride forward as far as you can, and plant your stepping foot; keeping your upper body vertical, dip your lower body straight down until back knee comes close to the ground; hold the tension in the front of your leg, then raise your body straight up and return to starting position. For straight leg lifts, you can lie on the floor, and keep your non-lifting leg bent slightly to take pressure off your back.
It is a good idea to begin each exercise without weights. This will allow you to grow used to using good form. Then you can begin to add weights; the safest way is to carry dumbbells by your sides for squats and lunges, and ankle weights for leg lifts.
For squats and lunges in a gym with a spotter you can carry a barbell across your shoulders behind your head. Complete one set of 12 repetitions, and begin light and increase weight slowly.
For your lower leg muscles, use standing heel raises and seated toe raises. Again, begin without weights and after a couple of weeks begin carrying light dumbbells. In a gym, you can use a barbell.
All these strength workouts are not replacements for speedwork; they are designed to get you ready for speedwork
They serve another purpose: "The most effective way to reduce injury risk is to improve your muscle strength," says AmericanRunning Editorial Board Member Michael Yessis, Ph.D., author of Kinesiology of Exercise.
After at least six weeks of one or more of these strengthening workouts, you will be in better shape for your speedwork, which will build you to a peak.
Copyright,The American Running Association.