In order that the athlete can attain maximum range, the angle of projection should be $45°$ and the maximum range will be given by, \[R_{\text{max}}=\frac{u^2}{g}\]
At this angle of projection, the maximum height the body can obtain is, \[H_{\text{max}} = \frac{u^2}{4g}\]
So, the athlete should attain a height of $\frac{u^2}{4g}$ to attain a longer distance of $\frac{u^2}{g}$.
[Read: Projectile Motion]
