Spring is around the corner, which means swimsuit weather isn't far behind.
But if you're one of the millions of people who might not have stuck to a New Year's resolution to get in shape, Drs. Mehmet Oz and Michael Roizen, authors of the hugely popular "You: On a Diet," can help.
They recommend an hour and a half a week of weights and cardiovascular activity. If you can combine them, that's great. You need to break a sweat for a minimum of an hour a week. Oz and Roizen recommend another 30 minutes a week of weights.
Below, exercises you can do at home to get fitter, faster.
The Curl-Up Test
The curl-up test evaluates abdominal muscular endurance. Both men and women perform the exercise in the same manner. (Note: These are not regular curls.)
1. Warm up for five minutes by walking at a moderate pace and tightening your abdominal muscles a few times.
2. Lie on your back with your knees bent at 90 degrees and your feet flat on the floor. Place your arms at your sides, palms down.
3. Lift your head, shoulders and shoulder blades off the floor. Hold for a moment and then return to the starting position.
4. Perform as many curl-ups as possible in a minute.
5. Record the number of curl-ups completed.
Consult the chart below to see how many curl-ups you should be doing per minute.
Age: 20-29. Curls: More than 35.
Age: 30-39. Curls: 25-29.
Age: 40-49. Curls: 20-24.
Age: 50-59. Curls: 15-19.
Age: 60-69. Curls: 10-14.
Age: 70-79. Curls: 7-9.
Age: 80-89. Curls: 4-6.
Age: 90-99. Curls: 1-3.
Age: 20-29. Curls: More than 45.
Age: 30-39. Curls: 30-34.
Age: 40-49. Curls: 25-29.
Age: 50-59. Curls: 20-24.
Age: 60-69. Curls: 15-19.
Age: 70-79. Curls: 10-14.
Age: 80-89. Curls: 6-9.
Age: 90-99. Curls: 2-5.
The Plank Test
1. Lie on the floor in standard push-up position with your toes on the ground, but place your elbows on the ground instead of your hands.
2. Maintain a straight line through your body with no arch in your back.
3. Keep your head down and in line with your back. Hold that position for as long as you can.
If you last less than 15 seconds: Your core muscles in your abdominals and lower back are on the weak side, meaning you're more vulnerable to suffering from acute or chronic lower-back pain.
If you last 15-45 seconds: You've got a nice foundation of strength, which will help protect your back, but there's still room for improvement.
If you last more than 45 seconds: Wow, can we see your abs?
On "Good Morning America," Oz and Roizen rebuked every excuse not to exercise.
You say: "No time."
Oz and Roizen's Excuse-buster: Our workout takes only 20 minutes, three times a week. Are you willing to admit that your life is so out of control that you can't spare even this short amount of time? C'mon. We know you make at least that much time for "Sex & the City" reruns.
You say: "No gym."
Oz and Roizen's Excuse-buster: Our workout requires no equipment. In fact, you'll use your own body as your gym.
You say: "No baby sitter to tame the demanding kids."
Oz and Roizen's Excuse-buster: In the time the kids are mesmerized by one episode of "Dora," "SpongeBob," or "Drake & Josh," you can get fully pumped.
You say: "No room for equipment in the house."
Oz and Roizen's Excuse-buster: The only weight you need is the fat sagging from your belly.
You say: "Working out is more boring than a 20-hour drive on the interstate."
Oz and Roizen's Excuse-buster: You'll stay fresh and focused if you keep the workout short and the music pumping. You pick the songs, and we'll have you moving from exercise to exercise in this accelerated workout so you won't have time to get bored.
You say: "Working out is too hard."
Oz and Roizen's Excuse-buster: You can customize the workout for you -- whether you're a beginner, intermediate or expert.
You say: "I don't have money for a personal trainer."
Oz and Roizen's Excuse-buster: This one's free. Follow our instructions above, or download three levels of our workout from Oprah.com.
You say: "Strength training? I don't want to look like an Olympic shot-putter."
Oz and Roizen's Excuse-buster: With our workout, you'll build most of your strength in your core -- to keep your belly taut and posture elegant. We focus on matching a strength exercise with a stretch to keep you limber and sexy. In the end, you'll look more like a ballerina than a ball player.