I bought a couple recently to do P90X2, reebok 3 and 5 kg I think. Anyway, the heavier one works a treat. One of the exercises is to use the balls on your hands in a push up, one ball per hand. The heavier one stays hard during this but the lighter one although hard to hold, when under pressure/weight indents in a bit on the top making it really hard to do the exercise with that hand. I thought there was a problem with the ball so got a replacement but the replacement does the same thing, so now I'm not sure if it's a fault with both balls or just they are all like that. Can anyone check their balls/know from experience?
Random question I know but I don't know where else to ask.