Many people become so focused on the lifting part of using light weights and the stretching part of using resistance bands for strength training that they tend to forget about one of the most important aspects of strength training, good posture.
Good posture is important for a number of reasons. The first is to avoid injury. Our back is incredibly flexible thanks to our vertebrae, muscles and joints. However, that flexibility can be a disadvantage when lifting weights, even light ones. This is because it is very easy for you to slouch during your exercise and for your posture to get increasingly out of alignment the more repetitions you do if you are not careful about your form. Bad form means less benefit and slower results, which no one wants when they are working so hard to improve their body.
In terms of resistance bands, good posture is even more important in order to avoid particular kinds of injury those who use them are prone to. Resistance bands can cause injury if they slip out of your grasp or snap. Keeping your head up, back straight and eyes straight ahead will protect your face from any snapping, as compared with looking down and slouching over the handles of your bands and getting smacked in the face by them.
To get the most out of each exercise, align your body correctly. This will usually be with your feet slightly apart or shoulder width apart and your body in a straight line from head to toe, with your back straight and abdominal muscles (abs) engaged so your hips do not thrust forward or shove backwards.
As you move from one position to the next, hold the form recommended for the exercise. You may wish to practice a few times without weights or bands first to see how it feels. If you work out in a mirror, you can also see whether or not your posture is good and if you are maintaining form as you work your way through each rep in each set.
Finally, good posture is particularly important if you are doing slow lifting versus natural count lifting. Most people do the 1, 2 natural movement with little thought, eager to get their reps and sets done. Slow lifting means taking as long as possible to move from one position to the next. Slow lifting puts more strain on the muscle, so good posture is essential in order to avoid injury and work the muscles deeply. Slow lifting is an excellent way to improve your form rather than just cranking out endless reps.
With more than 80% of all people experiencing lower back pain at some point in their lives, pay attention to posture to avoid injury and see what a difference it can make to your strength training.