When Did Resistance Bands Become a Thing?
In 1851, in fact. The first known band, The Chest Expander, was used more as a medical device for people who had weak chests.  Then, in 1896 a man named Gustav Gossweiler patented a 'resistance apparatus' which led to today's modern resistance bands.
So although resistance band fitness has become increasingly popular as of late, the original idea was created in the 19th century. Fast forward to the 21st century, we now have a vast array of options when it comes to resistance training.
Why Should You Use Resistance Bands?
It has been proven that resistance bands elicit the same muscle activity when used, and as a result of this, there is less chance of injuring yourself whilst using exercise bands as there is less pressure being put on your joints.
Resistance can be used for both ongoing fitness or as a part of a rehabilitation program after an injury. Due to the spectrum of strength that is available in resistance bands, they can be used in a targeted way to aid recovery. 
 Heffernan, C. (2017, December 11). The History of Resistance Bands. Physical Culture Study. Retrieved July 14, 2022, from https://physicalculturestudy.com/2017/12/11/the-history-of-resistance-bands/
 Pinkham, H. (2017, August 15). 9 Reasons to Use Resistance Bands for Working Out. ProsourceFit. Retrieved July 14, 2022, from https://www.prosourcefit.com/blogs/news/9-reasons-to-use-resistance-bands-for-working-out