Fix script exhaustion allowed execution time?

game.Players.PlayerAdded:Connect(function(player)
	while true do
		if player:WaitForChild("PlayerData"):WaitForChild("xpProg").Value == player:WaitForChild("PlayerData"):WaitForChild("xpReq").Value then
			player.PlayerData.xpProg.Value = 0
			player.PlayerData.xpReq.Value = player.PlayerData.xpReq.Value * 2 + 1000
			player.leaderstats.Level.Value = player.leaderstats.Level.Value + 1
		end
	end
end)

This is a script that when a player reaches the required xp to level, reset xpProg and set xpReq to be higher. However, when I try and test the script in studio, the client freezes and errors in output with script exhaustion: allowed execution time and leads me to line 5. How do I fix this, since I don't know how.