According to the consensus of the centers for disease control and prevention, the american college of sports medicine, and the surgeon general, engaging in moderate intensity physical activity on most days of the week, is associated with a % reduction in all-cause mortality. 20-30% 40-50% 10-20% 30-40%

10-20% should be the answer

Well if you pick a machine to work on and that's gonna be your exercise if you don't stick to that machine your muscle strength your muscle mass rather will change because you haven't been doing it you change something in your exercise routine which changes your body's form of dealing with things for example you might become weaker or stronger depending on what kind of exercises you do in whether or not the machine you picked actually your muscles grow.