Excuse: "I'm intimidated by all the equipment at the gym."
Got shoes? "That's the only gear you need—other than a good bra," says Lovitt. "Many sports store a quick gait analysis to help select the right sneakers for you, whether you have flat feet, a high arch, or need ankle support." Once you're laced up, press Start on the treadmill and walk briskly for 30 minutes. Follow that with push-ups or crunches, each time tackling a separate muscle group. Most gyms offer a free orientation for new members. If yours doesn't, spring for a trainer initially to revamp your routine.