2. Two-hour cardio sesh? Puh-leeze.
These days, people are looking for big results in a small amount of time. The good news is that when it comes to fat burning, less really can mean more. High-intensity interval training improves aerobic and anaerobic fitness, reduces blood pressure, increases insulin sensitivity, and burns stubborn abdominal fat while maintaining muscle mass, according to the American College of Sports Medicine. A 30-minute HIIT workout can burn roughly 15 percent more calories than a moderate workout of the same length.
While Ironman athletes still need those monster-weekend rides to build up the endurance and stamina required for extremely long competitions, people interested in lowering body fat and gaining lean muscle can benefit from two or three HIIT workouts a week.
More: What is HIIT?
A HIIT workout alternates intense efforts (80- to 95-percent max effort) with more moderate efforts (40- to 50-percent max effort). Exercises usually are 5 seconds to 8 minutes while the whole workout can take as little as 20 minutes up to one hour. HIIT workouts can include indoor cycling intervals, elliptical cross-training intervals, swimming intervals and group training classes that mix strength training with high-intensity aerobic drills like sprinting and mountain climbers.
The pros: HIIT exercise can be adapted into many regular workout programs with a little advance preparation. Instead of reading Us Weekly while on the elliptical, put your earbuds in and jam out while you put in 2 minutes of hard effort, followed by 2 minutes of easy effort for a total time of 20 minutes. Be sure to warm up and cool down. Look for HIIT classes at your local gym or community rec center.
The cons: You need to monitor your heart rate in order to get the most out of these workouts. The American Heart Association has an informational guide that describes how to calculate your heart rate based on your age.
It's best to use a heart-rate monitor, but if that's not in your budget, use the Rate of Perceived Exertion chart (RPE), which can be found online and in many gyms. Your hard efforts should feel between an 8 and 9 and your easy efforts to be about a 4 or 5. Holding these efforts on your own can be tough, so these workouts are often best done with a workout partner or in a class setting.
More: HIIT Workout Challenge
3. I want to look like a (badass) ballerina
Remember that scene in Black Swan when Natalie Portman pretty much breaks her ankle, barely flinches, and then keeps on dancing? Those lithe creatures dancing around on stage are some of the strongest athletes in the world—and they've inspired the masses who want to achieve that same level of fitness.
Ballet and Pilates-inspired barre classes are popping up everywhere. These hour-long workouts put the "b" in burn and feature upbeat music (think DJ Swan instead of Swan Lake).
The low-impact classes target those areas we all struggle with such as abs, butt, arms and thighs. Exercises can be modified to fit your fitness and strength level. The workout usually begins with a standing warm-up, followed by some high-rep, low-weight work, and then the rest of the class you'll be at (or under) the barre working your lower body and abdominals.
Chances are, there's a barre class studio within driving distance of your house (Pure Barre, The Dailey Method, The Bar Method, etc.). Monthly membership fees range from $50 to $175 a month, depending on how many times a week you attend class. Some of these facilities offer showers and daycare, making them a good choice for parents and working people on the go.
The pros: These classes, if taken regularly, will change the shape of your body in a good way. You'll see the most change if you go 2 to 3 times a week. However, you'll still see results if you can only squeeze in one session a week. The music and atmosphere of the classes are fun, motivating and accepting, as long as you remember to stay within your own limits. Prepare to be sore after class, especially your first few weeks.
The cons: There's a learning curve with these classes. The lingo, the feet positions, and even the structure of the class can take some getting used to. Start with an intro class (most facilities offer one at least once a month for free) so that you can get a good overview of what to expect. The price at many of the barre-only gyms is on the high side, so if you're looking for something a little cheaper, look for classes at your local recreation center. If you love it, then splurge for a monthly membership at one of the larger chains.
More: Best Fitness Apps for 2015
Stay in shape in a fitness class.
