Some good news for those finding it hard to find time or motivation for lengthy exercise sessions. It turns out that frequent little bursts of exercise about 1 to 2 minutes long also have tremendous health benefits, even if you spend most of the day sitting. Think of them as "exercise snacks".
An exercise or activity snack is a "brief snippet of exercise, usually lasting a minute or two, and done frequently during the day". There are studies (exercise snacking research!) finding it a good way to improve fitness, especially cardiorespiratory fitness and cardiometabolic health. The benefits of exercise snacking can be comparable to lengthier traditional workouts.
Some examples of exercise or activity snacks: walking quickly up and down a staircase, walking quickly around a room, rising and lowering 15 times from a chair, and jumping up and down. Ideally anything that'll raise your heart rate and breathing briefly. Sounds easier than going to a gym, doesn't it?
The Washington Post has a nice article about exercise snacking. Below that is an example of recent exercise snack research.
From The Washington Post - These 2-minute exercise bursts may be better than your regular workout
From Science Daily: Activity 'snacks' following meals may help maintain muscle mass
Interrupting prolonged sitting with periodic activity "snacks" may help maintain muscle mass and quality, according to a new study by researchers at the University of Toronto.