Doing squats can indirectly help extend the duration of sex by strengthening leg and core muscles, improving stamina, and overall endurance. Stronger muscles and better cardiovascular endurance can lead to greater stamina during intimate activities, reducing fatigue. Additionally, squats can improve blood circulation and enhance strength and control in the lower body, which can also benefit sexual performance.
However, extending the duration of sex involves multiple factors, including psychological state and sexual health, so squats are just one potential contributing factor.