In the 1500 metres, he placed fourth at the 2017 World Championships, and fifth at the 2020 Tokyo Olympics.

Over the 5000 metres, Mechaal won the silver medal at the 2016 European Championships.

He is a three-time European Indoor Championships 3000 metres medallist.

He also won two medals for the men's senior races at the European Cross Country Championships.

Mechaal held the European indoor 3000 m record set in February 2022 with a time of 7:30.82 at the New Balance Indoor Grand Prix in New York.