Serena Williams has announced she's back in training on court via Twitter.

The tennis ace has not played a premier match since last year's final at Wimbledon.

Since then she has suffered a number of serious health problems, including blood clots on the lung.

Serena tweeted it was her first day back and posted a picture of her in one of her typical bad taste outfits - a bright pink bodysuit.

 She did not say when she will return to the WTA tour however.