And as they slide their hand down the lever, they can push with a smaller effective lever length, but push through a bigger angle every stroke, which makes a faster rotational speed, and gives you an effective high gear.
手を下の方にずらして レバーの長さを短くして握り 一漕ぎの角度を大きくすれば 回転速度が増し ハイギアの効果が得られます