Loaded carries — farmer’s walks, suitcase walks, waiter walks, et al. — will build lean muscle, tone you up and shred fat like few other exercise. Plus it’s so easy a cavemen could… well, you know. Read this T-Nation article for pointers and walk this way!
[Note: Although this article is geared toward men, women can benefit greatly from loaded carries as well. Which would you rather do — an hour of boring treadmill jogging or 15 minutes of loaded carries that’ll make everyone stand up and take notice?]