Gravity's special offer 12 HIIT Fitness Class Pass is just £36! That's 12 uses at only £3 per session saving £24. Buy online now and bring the voucher with you next time you visit and we'll assign your pass to your account - a photo will be taken for identification verification. Pass is valid until to 31 Dec, is non-refundable, non-transferable and only valid for the park purchased for. Book HIIT Fitness sessions in park or by phone only