**3.1.1 The population tested**

29 healthy volunteers, full-time and extramural students of the Academy of Physical Education in Katowice, took part in a test. The volunteers were 28 years old (21÷48) on average. The order of taking the 6MWT on the treadmill and in the hallway was established at random. The tests with the use of both methods were performed at a 7-day interval.
