Picture via Wikimedia
You row to go forward but instead of water it's wheel
Fun fact: Every year about 10 randomly chosen white middle aged dads in the west are afflicted with rowbike madness and start trying to revolutionize this as the next best thing. They pull of frankly impressive engineering feats to produce the most contraption bicycle yet devised, here's an early 2020s example
I would say its off seas9n training for rowing, but it seems like rowing season. So maybe its that riders really want the helmet