local userInput = game:GetService ('UserInputService')
local Players = game:GetService ('Players')

local sprintSpeed = 30 -- how fast you want to run
local walkSpeed = 16

local player = Players.LocalPlayer

local function beginSprint (input, gameProcessed)
   if not gameProcessed then
       if input.UserInputType == Enum.UserInputType.Keyboard then
           local keycode = input.KeyCode
           if keycode == Enum.KeyCode.LeftShift then
               player.Character.Humanoid.WalkSpeed = sprintSpeed
           end
       end
   end
end

local userInput = game:GetService ('UserInputService')
local Players = game:GetService ('Players')

local sprintSpeed = 30 -- how fast you want to run
local walkSpeed = 16

local player = Players.LocalPlayer

local function endSprint (input, gameProcessed)
   if not gameProcessed then
       if input.UserInputType == Enum.UserInputType.Keyboard then
           local keycode = input.KeyCode
           if keycode == Enum.KeyCode.LeftShift then
               player.Character.Humanoid.WalkSpeed = walkSpeed
           end
       end
   end
end



userInput.InputBegan:Connect (beginSprint)
userInput.InputEnded:Connect (endSprint)