pressure chamber 8 is loaded with a high pressure a locking means 24 as described above is necessary finally a differential pressure sensor 92 with a pilot connection to the outside of fitness trainer 1 is arranged within pressure chamber 8 to monitor the pressure difference between pressure chamber 8 and the environment a wheel 94 on support plate 62 may help moving fitness apparatus 1 once assembled locking means 24 may comprise a hooking means such as a bolt 96 that can be locked against a biasing force by a pressure cylinder 98 to avoid accidental opening of housing 2 if not in use or during power failure bolt 94 is released due to the biasing force pressure cylinder 96 may be activated by a compressor 100 it is to be noted that in an alternative arrangement first part 4 may be stationary and second part 6 be slid away from first part 4 this however is not preferred as it requires a higher design effort to move exercise device 30 together with part 6 a person first grasps one of handles 20 to release locking mechanism 24 and to pull first part 4 away from second part 6 into the access position in this the person is aided by support device 90 the person enters pressure chamber 8 through the access opening and takes place on seat 38 and places.