Form matters, especially in sprinting. First of all and most importantly, if you want to avoid injury and if you want to get faster, stronger, better. Form is the most functional piece of the movement, without proper form, we’ll lose efficiency, optimization and maximizing potentiation.
Prioritizing form will allow for maximizing full potential of the joints and levers. That means the muscles, movements and actions will be fully optimized to work to their full capacity and then further develop, by getting stronger in those movements. Repetitive movements in the most optimized mechanics will strengthen itself upon itself but the same will also happen with faulty mechanics. Repeating bad mechanics will strengthen the muscles and reflexes around those movements. Which might be alright for a bit but inefficiencies will reach its limits, because of compensations and bad mechanics, which will eventually lead to injuries.
So how do we apply this principle to sprinting. It’s simple while sprinting as a workout, if you feel your form breaking down, failing or falling apart, just stop. If you find it hard to maintain your form, physically or mentally it becomes very difficult, don’t continue trying to fight through it or squeeze in an extra rep. This probably goes against what any trainer or coach has ever said. It’s always a “one more rep” mentality.
But the theory here is that we don’t want to continue doing extra reps with bad form. That’s when bad habits start because other muscles will start to compensate for the tired primary muscles. And once those other non-primary muscles start activating you’re creating a kinetic sequence that can be difficult to unlearn. Now the presumption is knowing what good form is, which is important but good form for sprinting won’t be covered here. Instead, generally, trust your senses, if it doesn’t feel good or natural, it could be wrong.
Prioritizing good form also involves another principle which is the The 80% Rule. Which I’ll just briefly touch on here. Under 80% – very easy effort, strain and focus is required to maintain good form. At 80% it should feel like it requires some effort, strain and focus to maintain good form but not too taxing. As you get closer to and move past 90% it will feel more difficult to maintain good form, requiring intense effort, strain and focus to maintain it and only for very short duration if at all. So theoretically you can throttle your efforts to always be practicing good form.