Do you need to use weights when working out?
Thank you for asking.
Resistance Training' is another name for exercising your muscles using an opposing force i.e. dumb bells, barbells or resistance bands or bodyweight exercises.
Any form of exercises that is based on above definition can help you build lean mass. Barbell training is very effective and faster to produce results, but bodyweight exercises are effective too, but it takes a long longer to achive lean muscle mass production.
Suppose you build a good foundation of lean muscle mass all over your body using weight training or bodyweight rourines. Suppose you combine a suitable nutrition and recovery system to the mix to get good results.
It doesn't matter which resistance routines you used to achieve the goal.
If you stop the process say for for few months and change your sleeping hours, then change your nutrition, then lean muscle mass production will slow down or totally stops. Layers of body fat may grow all over based on your choice of nutrition. The whole process is slow to gain and slow to lose.
No you don't need to use weights. It is significantly more effective and efficient to build lean muscle mass if you use a suitable weight training routine with a barbell.
Thank you. I hope i provided some clues.