Ralf Rangnick announced Thursday that he has resigned as head coach of Schalke, revealing that he has been suffering from exhaustion and fatigue.

The resignation will take immediate effect, ending Rangnick's six-month spell in charge of Schalke.

"After long and careful consideration, I have come to the conclusion that I need a break," Rangnick said via the club's website.

"This has been an incredibly difficult decision for me to take but my current energy levels are not enough to be successful or drive forward the footballing development of the team and the club."

Rangnick brought Schalke to the semifinals of the Champions League last season, losing out to Manchester United. He also achieved a 5-0 win over second division side Duisburg in the German Cup final.