Jason Ferruggia, Jim Wendler, and countless other top strength and conditioning coaches swear by hill sprints for fat loss and conditioning.  But why hill sprints?  Why not just plain, flat-land sprints?

Most people aren’t in good enough shape to run sprints!  If you haven’t ran a sprint since P.E. class in 1998 and are possibly carrying some extra poundage, going out to an open space and sprinting balls-out is a recipe for injury and disaster.  Most people new to sprinting proudly announce that they just “ran sprints for 45 minutes.”  No you didn’t.  And if you did, you need to notify the Olympic committee that you are on your way.  Nobody can run true sprints for 45 minutes. 

Benefits of hill sprints

Safety.
The hill sprint is safer than a sprint on flat land because the incline forces you to slow down.  Most people get on flat land and run an all-out sprint and have their limbs flailing wildly and what happens?  They pull a muscle.  You can only go SO fast on an incline and you are still working extremely hard.

Preserves muscle. 
The beauty of hill sprints is that they preserve all of your precious muscle because the work time is short!  A 5-10 second sprint is not enough time to start tapping into your muscle like other forms of high-intensity, long-duration cardio (think Spin, distance running – all highly catabolic).

Fat loss!
Hill sprints depend heavily on your muscular system.  Think of a hill sprint as a cross between cardio and weight lifting.  This means you get much more bang (fat burned) for your buck (time spent).

How far should you be sprinting?  I’d say between 20 – 40 yards, between 8 to 12 times, depending on the distance.  If you are brand new to hill sprints, start with 5 sprints.  Yes, 5.  Ease into it.

How long should your rest time be?  Go by feel.  There is no point in doing timed recovery and forcing yourself to go again only to half-ass it.  Take anywhere from 1-3 minutes if need be and then really get a good sprint in.  Sprint up, walk down, recover, repeat.

How often?  If you are just starting out, once a week.  After that, twice a week is plenty!  Hill sprints need recovery time just like anything else.  I typically choose to do hill sprints on my lower body lift days.  I find that it hinders my recovery time if I try to do them on separate days and still get my lifting in.

What should I do for a warm-up?  A warm-up is crucial.  Do not get lazy and skip it.  Take 5-10 minutes and do a dynamic warm-up.  Walk up the hill a couple of times, then jog up a couple of times, then run it once.  THEN start your sprints.  A full-bore sprint without a proper warm-up means injury!

The following are tips from Jason Ferruggia at Renegade on proper sprint mechanics.

•    Starting from the top down, the face must be relaxed. Do not clench your jaw or make any crazy faces. Relax.
•    Keep the chest up and shoulders back and down.
•    No side to side rotation of the pelvis, torso, shoulder girdle is allowed.
•    Hips remain forward toward the finish line at all times.
•    Arms should be bent ninety degrees with the hands open (no clenched fists or flailing, limp wrists).
•    When you are running the arms must pump vigorously, forward and backward. NEVER LET THE ARMS CROSS THE MIDLINE OF THE BODY. Only forward and backward. Little kids run with their arms side to side. Don’t do that or we will all make fun of you.
•    Think of pulling yourself through the air by driving your arms back as fast and hard as you can. The hands come up to a level even with the face and they come down and cross your pocket on the way back (but no further; don’t have them swinging way behind you).
•    Drive the knees high and be sure that the foot strikes directly under your body; not out in front of you (although, on a hill this may be slightly different depending on the incline).
•    Only the front portion of the foot should strike the ground; the heel should never make contact.
•    When the ball of the foot makes contact with the ground think of yourself as an animal pawing at the ground and rapidly pulling it behind you.
•    As Charlie Francis said, running takes place on the ground, sprinting takes place above it. If you do it right you should feel minimal impact or stress and should feel like you are flying effortlessly. If you’re taking a lot of pounding and it feels like a lot of work, you’re doing something wrong and should consider having someone watch or video tape you for some feedback.