Why is world record for 100m swimming slower than for 100m sprinting?

Answer 1

Swimming speeds are slower than running speeds because of the higher viscosity of water, compared with air. And, because swimming uses muscles substantially less effective than the major leg muscles.

[The average speed for the 200m running races is better than that for the 100m running race, because of the starting speeds not being instantaneous. ]

Answer 2

The differences in propulsion and energy expenditure between swimming and running contribute to the gap in world record times for the 100m distance. Swimming involves more drag, resistance, and limited ability to generate speed compared to running on land. Additionally, the human body is more naturally adapted for running rather than swimming, resulting in faster sprinting times on land.