This is what I do, and the why also. First find a nice flat stretch of grass. I'm currently running 50 yards because that's what I have to run on now. I've done 80 yards. Get rid of any hummocks or anything that might trip you up. No eating for at least 2 hrs prior and make sure you use the bathroom. No puking or embarrassing mistakes.
I spend about 10-15 minutes stretching before running. Quads, Hams and midsection.
I run regular running sprints first, fast as you can. You might want to start with 40 yards, even less if you find your speed dropping off. 4 sets of 4 sprints, you might want to start at 3 sets of 4 sprints. Make a pass, then walk about a 10 yards circle back to where you finished the first sprint, then hit it going back. 10 yard loop back to starting point and do it again. Like I already said, I walk loops for about 2 mins until my breathing is getting more normal, then go again. Just about when you think you can't take anymore, you're done with that kind of sprint. Get a small drink of water then start on karyokes (sideways right over left, then left over right) 4 sets of 4 ( or 3 of 4). You might want to only do 30 yards or so until you're used to it. Then sideways Scissor kicks, then Backwards, then when you're really getting tired, high kicking (like you're running through tires).
Now the why. This is a full body workout. Your heart and lungs are going to be put through it. You will be exercising all 4 of your energy transfer systems. When you hit it off the line, you're using available ATP. It'll run out during the first pass, and you'll transition to creatine - creatine phosphate to create ATP from ADP. About the end of the 2nd sprint, that will be done and you'll be using anaerobic respiration to produce ATP until the end of the set. Don't stop moving, keep pacing until the next set starts. While you're pacing, ATP will be made aerobically and you be recharging your other systems you just used so they are ready for the next set. By the end of the routine, most of your glycogen should be used up. Go ahead and eat well after. Your body should adapt to this and start storing more glycogen. This is going to make your endurance go up, and make you better and stronger athletically. I workout with weights pretty intensely. I have a sick ab routine. But when people ask me what my secret is, the sprints are it. It brings everything together. Your whole body has to work together to do them. I'm 54 by the way. Here's a couple of pics of the results of sprinting. BTW I've never taken any roids.
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