![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzJ-XoaLtC_rVeUf1PesAUk559RpgRt9AyP-lXnEKbeGixzBcD85dj0jrniTm-wpi3bJvql63oXcDQ4zy8Ib-o05qEK2DfnfIQl2sdfqbrUoYzox4uyDXXB_i19_cupG9kk41dSA/s400/roger+federer+yawning.jpg)
To prove he still full of energy and knows how to have fun, check out this video.
Leading his fellow team mates, Federer showcased his dark, deep voice chanting/singing "We are the Swiss" to celebrate their victory over Italy after winning 3-2 in the Davis Cup playoff yesterday.
(Image via menstennisforums.com)