You know how tired you get lugging heavy bottles home from the store? Time to capitalize on that. One-gallon bleach or water bottles can make great dumbbells. “You want a weight that will tire your arms after 12 to 15 repetitions…and these jugs are probably one of the heaviest items in the dollar store,” says Hoffman. “You can do a ton of exercises like lateral raises, biceps or hammer curls, back rows, chest flies, dead-lifts and so on.” They even have built in handles! If you find the plastic to be a little hard on your hands, you could always make a pair of gym gloves by buying a pair of gardening gloves for a $1 and cutting the fingers off.