How to check if Touched:Connect(function() is a humanoid?

So I started working on a racing game, and I wanted to add a stopwatch for the player to see how long it took them to go over the track. This is the script:

local stopwatch = 0


function stopWatchstart()
	while true do
		stopwatch = stopwatch + 1
		wait(1)
		script.Parent.Text = (stopwatch.."")
	end
end


game.Workspace.StartStopwatch.Touched:Connect(function()
	stopWatchstart()
end)

The problem is (I think its the problem, correct me if I'm wrong) that it starts the timer and adds massive amounts of seconds to the textlabel. How do I detect that the player that goes through the invisible part (startstopwatch) and not a random part?

What you need is debounce. Here is how it works.

local stopwatch = 0
local Debounce = false


function stopWatchstart()
    while true do
        stopwatch = stopwatch + 1
        wait(1)
        script.Parent.Text = (stopwatch.."")
    end
end


game.Workspace.StartStopwatch.Touched:Connect(function(hit)
	if hit.Parent:FindFirstChild("Humanoid") then
		if Debounce == false then
			Debounce = true
			stopWatchstart()
			wait(5)
			Debounce = false
		end
	end
end)

What this does is first it checks if the player that touched is actually a player (i.e it has a humanoid). Then we also make a debounce for the problem that you are saying that it is adding lots of seconds to the textLabel.

Hope this helps