Ideally you should aim to acquire a few different weights of dumbbells. (brandonricheyfitness.com)
Suppose, you are a beginner to fitness training and you go training with a 5 kg weight of dumbbell and do 10 repetitions with it. (mensquats.com)
If she progressed to the next heaviest weight of dumbbells the next time she did this workout, her body would think «Hey... what's this? (acaloriecounter.com)