I want player to lose stats like coins when running?

i don't have any code because i don't know what to put in it and please include where i put the script in it Thanks :)

First, we need to detect if the player is running or not.

game.Players.PlayerAdded:connect(function(p)
    p.CharacterAdded:connect(function(c)
        c:WaitForChild("Humanoid").Running:connect(function(speed)
           if speed > 8 then
print(speed)
        end)
    end)
end)

That script should detect how fast the player is going, usually when over 8 they are running, so you can raise it if needed

Now the removing coins.

local leaderstats = p:WaitForChild("leaderstats").Coins
 leaderstats.Value = leaderstats.Value - 1

To put them together do:

game.Players.PlayerAdded:connect(function(p)
    p.CharacterAdded:connect(function(c)
        c:WaitForChild("Humanoid").Running:connect(function(speed)
           if speed > 8 then
repeat
print(speed)
local leaderstats = p:WaitForChild("leaderstats").Coins
leaderstats.Value = leaderstats.Value - 1
until speed < 8 then

wait()
end
        end)
    end)
end)

make sure the last script is in server script storage