Biomechanics

Seitai rikigaku [生体力学] the study of the action of external and internal forces on the living body, especially on the skeletal system.

There are two exercises one can do to remain if fighting shape, the squat and the challenge/chinkuchi pushups.

There is plenty of research to support the squat and you can look at the push-up as second while also supplemental.

Here is what one article had to say about the squat:

“What is the single best strength-building exercise many of us could be doing right this minute but almost certainly are not? Consult enough exercise scientists and the latest exercise research, and the answer would likely be a resounding: squats.”

“For lower-body strength and flexibility, there is probably no better exercise,” said Bryan Christensen, a professor of biomechanics at North Dakota State University in Fargo, who studies resistance exercise.

“The benefits are not confined to the lower body. ‘It is really a whole body exercise,’

said Silvio Rene Lorenzetti, the director of the Performance Sports division of the Swiss Federal Institute of Sport in Magglingen. ‘It requires core stability and trains the back.’”

“Some people worry that squats can imperil the knees and hips, but the exercise can actually help protect and improve the workings of these and other joints, said Sasa Duric, an exercise scientist at the American University of the Middle East in Kuwait, who has studied squats. The movement ‘helps maintain the flexibility, stability and function’ of hips, knees and ankles, he said.”

“But perhaps most fundamentally, squats are key to living and aging well. ‘When we clean the house or plant a vegetable garden, we need to squat,’ Dr. Duric said. Ditto for easing into and out of chairs and lowering ourselves to toddler level for face-to-face playtime.”

“In essence, according to a 2014 scientific overview, squats are ‘one of the most primal and critical fundamental movements necessary to improve sport performance, to reduce injury risk and to support lifelong physical activity.’”

Now, as to the challenge push-up - a modified version of the classic push-up:

“Push-ups may seem like a basic exercise that works only your upper arms and chest, but when you do them the right way, they use muscles all over your body. You can do them just about anywhere, they can be adjusted to fit any ability level -- and they’re free!”

“Push-ups offer many health benefits, including:”

• Burning calories
• Protecting your shoulders and lower back from injuries
• Improving your balance and posture
• Improving your flexibility
• Improving your performance in sports and athletic activities

As to the additional benefits of the challenge push-up:

https://tinyurl.com/ane4heyt