Very steep hill sprints are great for building explosive muscular and anaerobic power, but many runners do them incorrectly by making them too long. When you're just starting out, begin with only about 10 seconds of steep sprinting, and give yourself a full two minutes between repetitions. Start off with four hill sprints per session and work your way up to six or eight as you get stronger.
Note that sprinting up a steep hill puts your ankles, knees and hip joints into unfamiliar angles. This places much more stress on those joints, and the connective tissue and muscles that are attached to them. For this reason, it's imperative that you be well warmed-up before your first hill sprint. Start with 10 minutes or more of easy jogging, and follow that up with two to four flat-surface sprints of about 10 to 20 seconds before you hit the hill.
It can be very beneficial to train running downhill, especially if you race off-road. Many trail runs are notoriously steep, both up and down, and running downhill calls on a different set of neurons to control a different set of muscles. It's safest to train this neuromuscular network on a dry, paved surface free of potential obstacles, so even dedicated trail runners will want to hit the pavement when it's time for downhill repeats.
As with other hill workouts, you'll want to warm up before you begin the repeats. Select a hill that is fairly steep—around 5- to 7-percent grade. Walk or jog to the top and then run down at a fast but controlled pace. Start with four repeats of 10 to 30 seconds, with a two- to three-minute rest between. As you build neuromuscular coordination and strength in your quadriceps, gradually increase the number of repeats and the speed at which you run them.
It's important to note that hill training places greater stress on the body than level-surface running does, so you should limit hill training sessions of all types to one or two per week at most. Also make sure the day after your hill workout is an easy run or a rest day.
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