Using hills to run faster will work if you do it properly. If you go about hill running for conditioning you may end up with overuse injuries. Less is better than more. Any type of hill running should be completed after your warm up and before your soccer training. Hill training should not be done at the end of training when you are tired!
Ideally you want the hill at a 45 degree angle and you need five to ten yards. Remember less is better than more.
Here is the progress of exercises:
1) Crawl up the hill for five to ten yards -do this five times and each time increase the speed.
2) Walk up the hill for five to ten yards with a forward lean from the ankles – five times
3) Walk up the hill for five to ten yards with a lean from the ankle with a partner giving you some resistance by holding you at the waist or using a beach towel around your waist
4) Run up the hill with your partner giving you some resistance. Focus on driving the leg into the ground. Rest for 30 seconds to a minute and repeat.
5) Run up the hill for 5 to 10 yards as quickly as you can. Rest for 45 seconds to a minute then repeat.
If you have a partner you can switch up in between runs for exercises 3 and 4.
After the exercise do some light foot work with the ball for recovery and preparation for the day's soccer training.
These exercises force you to drive the leg into the ground by using your glutei muscles.
This exercise may be put into your training once or twice a week with a 48-72 hour break in between. These are specific strength drills for developing soccer speed.