The world of physical medicine and rehabilitation still believes that exercise is medicine. Muscle mass will naturally decrease with aging, 3–8% every decade after a person turns 30 years old, getting worse over the age of 50 years, which is 5–10% every decade. Some studies state that for healthy people, resistance training (RT) performed 2–3 times per week with 12–20 total sets of exercises will add muscle mass. The addition of 1.4 kg of muscle mass was accompanied by the disappearance of about 1.8 kg of fat. RT plus aerobic exercises (AE) complemented with caloric resistance (CR) can result in a reduction of 5.1 kg or 7.1% of fat. Some research papers state that for stable CAD patients starting with 3 months of AE followed by an RT program of 40–60% intensity 1x RM, 1–2 sets, 8–10 repetitions, 2–3 days per week, duration not more than 60 minutes. Recommendation for a person with intellectual disability can be simple and harmless RT tools. The prescription for COVID-19 survivors consists of AE for 5 to 30 minutes with low to moderate intensity, plus 1–2 sets of RT, 8–10 reps at 30–80% 1xRM.