Arond 0:40 of this video, observe how the arm insertion into water is highly agressive, and how this agressive arm movement is used to strech the arm as far ahead as possible. Also notice 180 degrees arm extension in catch, and how fast the arm actually moves right in the catch phase of the swim. This requires enourmous strength in arms. In TI tecnique, arm movement accelereates as arm moves backwards, but as you see from this sprinter video, the arm moves very very fast already in catch phase. This is something you are unable to do if you have practice only TI for three years. Also sustainability will not improve your stroke speed, you must solve this through lower arm strength and catch-phase strength.

Good luck.

Your comment on sustainability only applies to people who also do long distance swimming. If you primarily want to sprint, TI is not the only method you can apply. My experience is that you gain a lot of efficiency doing TI excersises, but what you learn requires enormous strength for sprinting. The answer thus becomes to find a balance between your possible strength in a 100m run, and efficiency including drag.

Unlike you seem to suggest, a 100m race should have a totally perfect exhaustion of energy. It is not enough to only disperse the energy in a sustainable way equally for all four or two lengths of the sprint.

My advice to the person asking the question is to do strength/muscle excersises, preferably with a stretchband, to improve accessible strength for a high efficiency run.

Also, an area where TI does not excersise energy output is reach. It is very possible to improve sprinting speed with TI tecnique, by trying to deliberatly with muscles try to strech arms further in both directions. Core muscles can also be further involved in stiffening and turning body for optimal rotation.

1. Do TI swimming with higher focus on streching to maximum with 180 degrees arm and active use of shoulder/chest/back muscles for streching arm both in catch and end of stroke.
2. Do muscle excersises with strech band, particulary to imrove arm strength in catch phase of arm movement.
3. Do rythmic kicking excersises, that does not involve continous kicking, this matches TI swimming efficiency better. Do theese with kickboard but holding only the end of the kickboard so it is possible to include body rotation in kicking excersises.

Theese three steps has enabled me to take the best of efficiency from TI into sprinting.

I would also add that TI breaststroke key points cannot be transfered to sprinting. Arms are important for propultion in breaststroke sprinting, but key element to enable this is to apply a strechband between knees when doing breaststroke kicks. This removes some propultion from kick, but increases streamline that can be taken advantage of by enhancing propultion in arm movement.

Do not preach TI for sprinting, but understand the reasoning behind it. Ask any elite swimmer, sprinting requires agression in the right phases, not only sustainability. It might be that non-elite swimmers that also focus on long distance can use the above answered TI sustainability tecnique, but it isn’t good enough for say masters swimmers on top level. We all need agression and push to take full advantage of our bodies energy capacity on a 25 second run. Sustainability alone is no enough to deplete the bodys energy potential in that short time.

I will also add that events where agression is part of the tecnique, contribute to adrenaline, and can also enhance body output. I doubt mental stratergy of sustainability is comparable in this respect.