“I’m trying to solve a mystery… Been doing some swimming drills and I feel like my standalone kick is quite fast relative to other people.. .i.e. just did a 6x200m set – the 3rd 200m was arms only and then final 200m was full stroke. Granted I was more tired in the last one but still, my time for both was identical. Just puzzled as to why – if my kick is good – it’s not making much/ any difference to overall speed??? “
Even for the best swimmers the legs only add about 5%-7% to the total compared to 93+ from the arms.
Depending on size of feet, ankle mobility this varies a little.
For short distances perhaps you would be a lot quicker swimming with arms and legs compared to arms only as you can really work them <but at a high energy cost which cannot last.>
Times for longer distances tend to narrow as the legs provide balance and assist rotation but not really propulsion. The energy needed is too much. You should be a little faster swimming full stroke FC rather than pulling, if not it might indicate there is an issue with the kick mechanics.
“So I guess the answer is to get a stronger upper body?”
Yes to an extent, it is more about endurance ie a little stronger for longer so that the stroke does not shorten and get hurried. Paddle work can help, more swimming will help, adding the other strokes (so you X train a bit). Gym work can help, a swim bench will help. Dryland shoulder strengthening will help. Pool based swimming specific strength movements will also help. But none will help if the legs and body position are not streamlined and kept parallel to the surface. As a swimmer I would always take a perfect streamlined body position over a fantastic arm pull. Strong arms will eventually tire of pulling dragging legs.