No, no, no. It’s not “sprinting” at all. On the contrary, your forward momentum is much slower even than regular running (I’m talking about Steep Hill Running here). Imagine performing one of the sprinting drills, High Knee, on the hill but not pumping your knees up as vigorously or quickly as that… The idea here is a transition from marathon conditioning to faster, harder track work; or from aerobic to anaerobic; and to reintroduce power and flexibility in your strides. If you run it too fast, (1) the whole session (the uphill segment) is going to be shorter, meaning you will not apply as much resistance to your legs which is the whole purpose of this exercise, (2) the segment will become too highly anaerobic (uphill running WILL be somewhat anaerobic but you don’t have to encourage it more than necessary) and (3) because of that (lactic acid build-up), your form will be more likely to tighten up, that means you will be teaching your body incorrect movement. Take it slow. Concentrate on high knee, good posture, straight arm swing and good push-off with your toes. If you do have a 800m hill, the uphill section may even take good 4 or 5 minutes but the time is irrelevant. But, believe me, even the forward speed is slow, if done correctly, you WILL feel it a lot in your legs!
Bounding and springing are a bit different. You need to get some momentum to get going. Again the speed is irrelevant but you need to go fairly fast to keep that momentum. These will get you more lactic acid (for those who like to have it a lot in your blood stream…). Great exercises, but this is the reason why I personally don’t like to encourage these as a transition. Start with Steep Hill Running and work your way into other exercises. You can certainly mix them all up but you don’t need to either. Steep Hill Running will work more on your knee lift and endurance. Hill Bounding on back-leg extension and Springing on ankle flexibility. Latter two more for speed development as opposed to speed endurance or speed maintenance with Steep Hill Running. So depending on your event and your strengths and weaknesses, you can switch around the ratio of these exercises. I’ve been working on a chart to show a general idea of how much of which exercise you should concentrate but it’s not complete yet.
Lately a short sharp all-out sprint over a short hill (10 seconds?) has been very popular due to coach Canova and coach Hudson. I’m not against that type of exercise at all (Lydiard would have said any hill training would be good!). In fact, there may be a perfect place for that type of workout. Many great athletes have simply sprint, or run, up the hill (Eliot, Ovett, Coe, etc.). That’s perfectly fine too. But with the Lydiard program, these are 3 hill exercises and the purpose of those exercises are as stated and, depending on which part of overall training program you are in, the nuance may be slightly different. I know of one Lydiard disciple (directly coached by him) who don’t necessarily perform “original hill exercise” but just run up the hill. He did say, however, that he and his runners don’t necessarily “run fast” but “run hard.” There is a difference.