Resistance bands can be bought singularly or often in a set so it might be an idea when you’re starting out to invest in a set which will still be relatively inexpensive so that you can gauge for yourself what resistance you need where. It’s likely that your legs are going to be a hell of a lot stronger than your arms for example so switching around your resistance band strengths is a good strategy. The strength of the band will most likely be denoted by its color but you will also be able to see and feel the difference in thickness and length which will affect the overall resistance. There are 4 main levels of tension and they will take you from a light or rehabilitation style workout right through to supporting your advanced needs. Note though that for some types of exercise where the band is intended to support your own body weight, lighter can in fact be more difficult!\r