Sprint | Roblox Studio

local inputService = game:GetService("UserInputService")
--Settings(can be changed)
local normalWalkSpeed = 16
local sprintWalkSpeed = 32
local key = Enum.KeyCode.LeftShift

inputService.InputBegan:Connect(function(input)
    if input.UserInputType == Enum.UserInputType.Keyboard then
        local keycode = input.KeyCode
        if keycode == key then
            local character = game.Players.LocalPlayer.Character
            local humanoid = character:WaitForChild("Humanoid")
            humanoid.WalkSpeed = sprintWalkSpeed
        end
    end
end)

inputService.InputEnded:Connect(function(input)
    if input.UserInputType == Enum.UserInputType.Keyboard then
        local keycode = input.KeyCode
        if keycode == key then
            local character = game.Players.LocalPlayer.Character
            local humanoid = character:WaitForChild("Humanoid")
            humanoid.WalkSpeed = normalWalkSpeed
        end
    end
end)