Thought i would give you our take on pull buoy training at Fluid swimming.
Swimmers come in many shapes and sizes and especially so with triathletes; large and small, some float and some don't.
This provides the key to whether each individual should be using a pull buoy in training.
The pull buoy does two things, it provides artificial flotation to the lower limbs and also cuts out the kick and all that provides the swimmer.
If a swimmer naturally has a 4-6 beat kick then i would not be encouraging the swimmer use a pull buoy outside of drills or recovery work. The pull buoy would likely take away the kick drive and body balance the swimmer relies on and effect the position of the swimmer. When a swimmer has an effective kick then their legs and hips usually sit higher in the water. The pull buoy would be counter productive to this and effect the swimmers natural stroke kick balance.
If the swimmer naturally has a 2 beat kick, then it is more likely that the pull buoy would assist the swimmer with buoyancy and body position. It would bring the hips and lower limbs up and reduce frontal drag. So i would encourage these types of swimmers if they feel it benefited their speed to use pull buoys in training.
The other aspect that must be accounted for when setting pull sets for swimmers is the difference in natural flotation between the sexes. Typically women tend the float more as they have a more even distribution of fat through the body, whereas men, especially triathletes who have a low percentage of fat in the body tend to sink especially in the lower limbs. Couple that with low drive from the kick, and this has a bearing on whether a pull buoy assists or hinders an athletes swimming speed and efficiency.
Swimmers come in many shapes and sizes, so the pull buoy can be a friend or foe in the training pool. I find as a coach it's best to ask the swimmer if they like using pull buoys, and if they don't then i do not use them with that individual.
For the most part, our squad uses pull buoys for recovery and drill purposes, but if a swimmer really benefits from using a pull buoy outside of those times, i don't necessarily discourage its use. You will see them swimming longer and stronger with the pull buoy attached, and lets face it, a wetsuit is really just one big pull buoy anyway.
So don't be a pull buoys Nazi and ban them from the deck.