If you're looking to tone up for bathing suit season, having your own set of dumbbells at home will motivate you to squeeze in reps whenever you have a few spare minutes. You can do all the strength training exercises you've learned here on FitSugar, moves from your personal trainer, and ones from fitness DVDs, but you'll quickly realize something — you'll zoom through 50 reps of easier moves like bicep curls, but may struggle to do eight reps of more challenging exercises like chest-opening triceps lifts.
When you're strength training, certain muscles are stronger than others, so that means modifying your routine with different weights in order to target your muscles effectively. I keep a set of six-, eight-, and 10-pound weights on hand, and depending on the difficulty of the exercise and the strength of my muscles, I change up the weight. You'll know the dumbbell is the correct weight when your muscles become fatigued after 10 to 12 reps. Follow that rule when lifting and you'll spend less time pumping iron, but will achieve quicker results.