The value of bodyweight training – using only your bodyweight for resistance instead of machines or equipment – is often underestimated. In fact, bodyweight training can be an effective type of strength training and a good addition to your fitness program as it is a “high output, low input” training which improves your balance and flexibility. The resistance training effect you get from using your body weight can be as effective as training with free weights or weight machines.

Many different types of body weight exercises can be performed to work all of the major muscle groups. And body weight exercises can be done anywhere, using no extra equipment, at no extra cost to you.

To use your body weight in strength training exercises, try exercises such as squats, lunges, abdominal crunches, pushups, pullups or step-ups. Keep movements smooth and controlled. Strengthen the opposing muscles, such as the chest and back muscles, and strive for muscle balance.

Once you can easily do 12 to 15 repetitions of a particular exercise, try alternative forms of the exercise to give you more resistance or challenge. 

But always remember to use proper form and technique throughout each body weight exercise in order to get the most benefit and to avoid injury. And remember to take at least one day off between exercising each specific muscle group, in order to give your muscles time to recover.

References:

https://www.mayoclinic.org/healthy-lifestyle/fitness/expert-answers/body-weight-training/faq-20147966

https://www.bona.co.za/5-benefits-of-bodyweight-training/