This is a particularly interesting subject when it comes to individualization in swimming.
Those who practice rock climbing use the term 'Ape Index' when measuring the difference between the span of the arms and the height of the person. For example, if your wingspan is 3 inches larger than your height, then your "Ape Index" is +3. If your wingspan is 2 cm less than your height, then your "Ape Index" is -2.
To measure your "Ape Index" you can simply extend your arms in front of a wall, then by keeping your fingers in the same position you can measure the difference with your head. No need to be super-specific.
But what is the connection with swimming?
Well, if you have short arms for your height (apex of zero or less), then there is little chance that developing an amplitude swim with the fewest strokes possible per length will work for you: you risk becoming slower and less efficient while attempting to do as little of an arm stroke as a swimmer with a positive index apex.
If this is your case, do not despair, on the contrary, you are able to swim at a higher pace without "fighting" with the water. Developing a style combining a shorter movement but putting more frequency is your solution to swimming faster and more efficiently. Trying to copy the styles of elite swimmers (almost all of whom have albatross arms) won't help much. On the contrary, to encourage you, note that triathletes and open water swimmers favor a higher cadence and a shorter amplitude in their swimming in order to better get through difficult conditions and to favor cardio rather than muscular work.
You can make an analogy with cycling, cyclists with shorter thighbones tend to favor shorter crank lengths in order to increase the speed of rotation of the legs.
Swimming with "running" arms (negative index ape)
If you have short arms then watch this video, Hannah's is an intermediate level swimmer, she swims around 1'40 / 100m (50m pool).
At Swim Smooth we believe that there are two "ideal" types of swimming: the "Smooth" style and the "Swinger" style. The Smooth style is what most people think is the most effective - swimmers like Ian Thorpe and Michale Phelps use this style.
However, a shorter amplitude and a higher cadence can be just as effective, especially when combined with a 2 beat kick. We call this style "swinger" because the arms tend to come out to the side when covering.
Legendary swimmers such as Janet Evans, Laure Manaudou, or Shelly Taylor Smith have used this style with the success we know, collecting Olympic gold medals and world records as a result.
Swimming with long arms (Ape Index positive)
If your arms are long compared to your height, then a 'smooth' style in amplitude should work well for you. However, be careful not to amplify it and add "pauses" thinking "slipping" during your support: this would create downtime, pauses where nothing happens and where you slow down. Moreover, it harms your grip because you risk slipping it in order to "catch up" the time lost by the induced pause The true "Smooth" does not have any stopping time in their swimming, their hand in front is always moving, entering the phase of support much more quickly than an " over glider ".
The "Ape Index is just one of the many physical and physiological aspects that go into the individualization of swimming. If you find that certain tips are not helping you improve (or even slow you down), and you have put all of them into it. the effort required, then ask yourself if this was right for your style. In swimming and lifeguard training, like with most everything, there is no one recipe that works for everyone.