Lady GaGa's tour rider includes bikes.

The 26-year-old singer has bought two yellow custom-made Soul Cycle spin bikes, which retail at around $2,200 each, so she can keep fit on her 'Born This Way Ball' world tour.

Gaga has purchased some of the first machines produced in partnership with Villency Design Group from the production line in time for her run of gigs - which kicks off in Seoul on April 27 - which will take her to the UK to perform in London and Manchester later this year.

The 'Paparazzi' hitmaker is determined to keep fit during her tour, and she has been doing ''back to back spin classes'' to make sure she is in top condition ahead of her energetic performances.

She recently tweeted: ''Just killed back to back spin classes. Eating a salad dreaming of a cheeseburger #PopSingersDontEat #IWasBornThisWay (sic)''

But Gaga's tour preparations have hit a ''serious'' obstacle after she was forced to call a meeting over the use of fog while she is performing.

She tweeted: ''You know there's something wrong with you when you call a tour meeting only about 'fog.' It's serious people.

''Worse comes to worse ill just fog myself in the corner during Bad Romance. (sic)''

Gaga has also taken emergency advice from astrologers over worries that the stars will be aligned in the wrong direction when she goes on her world tour.

A source recently explained: ''Gaga is worried as she wants the stars to be aligned when she hits the road. She follows her horoscopes closely and has been looking ahead for when she's away.

''She's a typical Aries - outgoing with a sense of adventure. But when she found out Mercury is likely to go retrograde, she wasn't happy and has been talking it through with her spiritual team.''