I am asking about a National Champion Dog Agility Competitor wishing to improve her sprint mechanics. Through corrective exercise and conditioning she has greatly improved her athletic performance. She wants to correct her posture when sprinting a straight line at the end of the course for more acceleration/speed.
A combination of things. Things like speed and acceleration are ultimately a function of Maximum Strength. Right away you can set her up for success with a focus on increasing her Maximum Strength in movements that simulate running mechanics (i.e. squats, deep runner’s lunges, knee raises/tucks). As you establish more strength you can transition to Power training with things like box jumps and hang cleans. With a focus on technique, strength training will improve posture and serve corrective purposes. The idea is to break down and practice movements so that in the middle of competition the mechanics come naturally without thinking. You might look into Kelly Starrett’s breakdown of Spinal Bracing as well as his ideas on Squat Mechanics if you haven’t already. Once you’ve followed those steps you should work on actual sprint workouts. Notice that I have essentially outlined 3 Periodization Cycles (3-6 weeks each). Of course, I don’t know what her competitive schedule is, but this would be timed to lead into the competitive season leaving room for a transition period to rest her body (ex. 1-2 weeks @ 65%). Iin the case that she competes year round, you can mix and match these ideas in Micro Cycles. Hope this helps!!!