A source close to the star told the Daily Mirror newspaper: "Rob suffers from crippling anxiety and has been worried about the
lads' forthcoming concerts. A pal suggested Bikram yoga to refocus his
pent up energy and handle stress more effectively."
Robbie has been taking for three months consideration exercise.
The source added: "After a couple of sessions he was hooked - and sweating like a
wildebeest. While the others have stuck to the gym or pool, Robbie's
been using meditation and yoga to help his stage fright and to keep sane
on tour."