An Athletic in the Olympic games covers a distance of 100m in 10 sec.  His K.E can be estimated to be in the range of,

 $\text{ Average velocity is\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}}{V}_{Avg}=\frac{100}{10}=10m/s$
  $$\begin{gathered} Assuming an Athlete has mass may vary from 50 kg to 100 kg \\ for an athlete of mass = 50kg ; KE=\frac{1}{2}m{V}_{avg}^2=\frac{1}{2}\times 50\times {\left(10\right)}^2=2500J \\ for an athlete of mass = 100kg ; KE=\frac{1}{2}m{V}_{avg}^2=\frac{1}{2}\times 100\times {\left(10\right)}^2=5000J \\ KE could \text{be in the range of 2500 J to 5000 J} \end{gathered}$$