When you move up in a weight, move up the smallest increment possible. If you can still do 12+ reps at the new weight, move up another increment again.
Dumbbells are traditionally referred to in terms of the weight of 1 dumbbell, so you are really talking about a 5 kg set, and 7.5 kg set and a 10 kg set.
The 5 kg set just doesn't have the capacity to grow enough. I'd go with the 10 kg set, this will give you every weight possibility between 2 kg and 10 kg, in .5 kg increments.
The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.
| current weight: 178.0