I tried them during the lockdown and found the whole experience very frustrating. The force follows Hooke's law and scales linearly. Let's say you take one mark

I tried them during the lockdown and found the whole experience very frustrating. The force follows Hooke's law and scales linearly. Let's say you take one marked as 14-34kg. Suppose you replace a dumbbell of 24kg. It means that in extremes of your range of motion it is either way too easy or way too hard. Sometimes it is not too bad, If you do shoulder press, you're at your weakest in the bottom. Sometimes it is the other way around and you start craving iron.