Roblox Sprint Script Development

I'm looking for a Roblox script that enables players to sprint by holding down the shift key.

Requirements:
- Player stops sprinting when shift is released
- Fixed sprint speed (no customization needed)
- Visual indicator required (speed effect or animation)

Ideal skills and experience:
- Proficiency in Roblox scripting (Lua)
- Experience with player movement mechanics
- Ability to create smooth visual effects/animations