Law 17 (Practice on the field)
1. Practice on the field
(a) There shall be no bowling or batting practice on the pitch,
or on the area parallel and immediately adjacent to the pitch,
at any time on any day of the match.
(b) There shall be no bowling or batting practice on any
other part of the square on any day of the match, except before
the start of play or after the close of play on that day.
Practice before the start of play
(i) must not continue later than 30 minutes before the scheduled
time or any rescheduled time for play to start on that day.
(ii) shall not be allowed if the umpires consider that, in
the prevailing conditions of ground and weather, it will be
detrimental to the surface of the square.
(c) There shall be no practice on the field of play between
the call of Play and the call of Time, if the umpire considers
that it could result in a waste of time. See Law 42.9 (Time
wasting by the fielding side).
(d) If a player contravenes (a) or (b) above he shall not
be allowed to bowl until
either at least one hour later than the contravention
or there has been at least 30 minutes of playing time since
whichever is sooner. If an over is in progress at the contravention,
he shall not be allowed to complete that over.
2. Trial run up
No bowler shall have a trial run up between the call of Play
and the call of Time unless the umpire is satisfied that it
will not cause any waste of time.