Tip toe walking

My little one has been tip toe walking for a while now. Initially he would do it for a few seconds then switch to heels down. However lately I’ve noticed he is tip toeing a lot more and trying to cover longer distances on his tip toes. I asked the nursery if they’ve observed this too and they said yes however as he isn’t 2 yet, they are not concerned. I just wanted some advice, I am worried about the impact on his physical health so will tend to pick him up if I notice him doing it. He doesn’t yet understand when I encourage him to put his heels on the ground. Do you think by picking him up I am limiting his opportunity to explore with the walking and I should be allowing him? I just worry about his muscles etc and whether this can cause him any pain.