4. Run hills.
If done right, hill workouts usually aren’t fun. But hill workouts can put some pizzazz in your otherwise mundane interval workouts, and they can go a long way in building dynamic muscle strength that can come in handy when you’re fatigued and struggling to finish the last miles of your next half marathon. And running uphill is actually easier on your body because there is less jarring impact.
There are essentially two ways to run hills—either short and fast reps (say 8 x 20 seconds) that send you into oxygen debt right away or longer reps (8 x 1 minute) that start at a moderate pace but eventually increase in intensity because of the incline. The shorter reps, which can be done on a slightly steeper hill, build strength and power, while the
longer reps, done on a long, moderately sloped hill, build speed and add horsepower to your anaerobic engine. With either type of hill workout, stress good form; a short, quick arm swing, upright posture and soft, midfoot or forefoot footstrikes maximize the training effect and eliminate unnecessary muscular strain.