The Physical Activity Guidelines for Americans were created by the Office of Disease Prevention and Health Promotion. This publication recommends that all adults should avoid inactivity to promote good health mentally and physically. For substantial health benefits, adults should participate in at least 150 minutes a week of moderate-intensity, or 75 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity. Aerobic activity should be performed in episodes of at least 10 minutes, and preferably, it should be spread throughout the week.
Calisthenics. There's nothing fancy about a calisthenics workout, but just because it's basic doesn't mean it's not effective. A 2017 study in Isokinetics and Exercise Science put a group of untrained individuals through a calisthenics program to test the effectiveness of an exercise method that uses no equipment. Participants did a brief workout consisting of four or five exercises three days a week for eight weeks. At the end of the trial, all participants had significant improvements in posture, strength and body composition.
^ Osawa Y, Azuma K, Tabata S, Katsukawa F, Ishida H, Oguma Y, Kawai T, Itoh H, Okuda S, Matsumoto H (2014). "Effects of 16-week high-intensity interval training using upper and lower body ergometers on aerobic fitness and morphological changes in healthy men: a preliminary study". Open Access Journal of Sports Medicine. 5: 257–65. doi:10.2147/OAJSM.S68932. PMC 4226445. PMID 25395872.
New (July 2011) guidelines in the United Kingdom include the following points: The intensity at which we exercise is key, and light activity such as strolling and housework is unlikely to have much positive impact on the health of most people. For aerobic exercise to be beneficial it must raise your heartbeat and make you sweat. The more exercise you do, the better. Everyone should do a minimum of 150 minutes a week of moderate-intensity aerobic exercise but that really is the minimum for health benefits. If you can go beyond 150 minutes, you’ll gain even more health benefits. Sedentary time (time spent sitting down to watch TV, use a computer, read or listen to music) is bad for your health, even for those who are achieving 150 minutes of exercise a week. These guidelines, are now much more in line with those used in the US, also include recommendations for muscle-building and bone strengthening activities such as lifting weights and yoga.