I cant do running sprints right now.
my favorite sprint workout right now is using an aerobics step. Facing a clock......go on the minute
If you are really out of shape start with no risers or 1 riser. up-up-down-down = 1
Do 20 reps as fast as you can. Rest until the end of the minute. The first set maybe your interval is 12-15 seconds and you rest for 45-48 seconds. So the faster you go the longer you rest. repeat. Every 3 sets add a riser (time to add the riser is included in your minute you do not get extra rest). Continue until you can not complete 20 steps in 30 seconds. (push yourself to do as much as you can) If you get beyond 12 sets, next time start with a higher step.
If this is still too hard on your ankles use an elliptical and pick an rpm to hit for 20 seconds.
MTA: because it is rare I dont have more to say
"When I got too tired to run anymore I just pretended I wasnt tired and kept running anyway" - my daughter Age 7