Slideshow Pictures: Exercise & Fitness -- 20 Hottest Fitness Trends for Men and Women

Tabata: Four Minute Fat Burn

Yes, you read that right. Super short workouts can bring lasting results. But to burn fat in just four minutes, you’re going to have to work harder than you thought possible. For a Tabata-style workout, begin with a 5-minute warm-up, then push yourself to the max. Run in place, jump rope, or do squats for 20 seconds. Rest for 10 seconds. Repeat for 4-8 cycles.

Sprint Triathlon: Ironman Light

If you’ve got the guts for a triathlon -- but not enough hours to train -- try a shorter version. A sprint triathlon is a half-mile swim, 12-mile bike ride, and 3-mile run. In a triathlon relay, team members work together to complete a regular triathlon. A checkup is a must before any new workout if you're 45 or older or you have health issues.

Barre Belles: Bootie Ballet

Borrow some moves from a ballerina to sculpt a strong, lean shape. Simple work on your toes can tighten your midsection and boost your strength. Studios offer classes, or you can follow a video at home. One to try is the plié: Stand with your heels together, toes apart, and then bend your knees. Squeeze your inner thighs and glutes as you slowly go lower and then rise to standing.

Tough Mudder: Mud, Sweat, and Tears

Imagine your workout as a Survivor episode or Special Forces training. Only the fit and fearless can tackle an obstacle race. In the Tough Mudder, you crawl through mud (of course), climb 12-foot walls, and swim in icy water. Train for at least 8 weeks with sprints, squats, push-ups and weights. Rest between short bursts of exercise. Be aware that an extreme challenge also brings safety risks.

Rebounding: High Flying Fitness

Want a true exercise high? Try a cardio class on trampolines, which is also known as rebounding. You’ll burn fat with an extra bounce in your step and it’s gentle on your joints. If you can’t get to a trampoline center, you can get a similar boost with a mini-trampoline at home.

Elite Fitness: Muscle Confusion

For hard-core fitness, try the workout made famous by Republican vice presidential candidate Paul Ryan. Cross-training programs like P90X (Ryan’s favorite) and Insanity Workout aim for "muscle confusion." They switch up exercises, add new moves, and often include jump training, also called plyometrics.

Flywheel: A New Spin on Cycling

This high-tech spin puts extra heat in your workout. Flywheel bikes have sensors that check how hard you’re working. Your name -- and your stats -- can be flashed on a large screen to compete against your fellow indoor cyclists. Flywheel and other new spinning programs also use upper body weights. Some spinning studios combine cycling with yoga or Pilates.

Kranking: Spinning With Your Hands

Pedal with your hands on a Krankcycle for an intense upper body workout. It builds strength and tones your arms, shoulders, pecs, and upper back. Krank in a standing position and you can burn as many calories as you would from an intense lower-body cardio work. Add kranking to mix up your workout or to keep fit if you have a leg or foot injury.

Zumba: Dance Fitness

Zumba wants your workout to party! This high energy dance-fitness class moves to a Latin and international beat, instead of counting repetitions. It's one of the most popular workouts, and it burns more calories than kickboxing and step aerobics. For a different twist, try an aqua version or QiDance, which moves to world music.

CrossFit: Maximum Fitness

You can burn about 15 calories per minute with this intense workout. Work to your max with squats, push-ups, gymnastic rings, intense runs, and weightlifting. “Hero Workouts” are named in honor of soldiers who died serving the country. Be aware that the bursts of intense exercise can lead to injury. It’s important to work on your flexibility and learn to do the moves properly.

ViPR: Whole-Body Movement

ViPR sounds like a killer workout, but the true goal is strength and fitness for everyday life. You use a heavy rubber tube to lift, push, twist and work your whole body. ViPR adds moves that boost your workout whether you’re just starting or you’re a top athlete. Choose the size and weight that fits your needs.

Kettlebells: A New Weight to Lift

A vigorous workout with a kettlebell -- a cast iron ball with a handle -- can burn 272 calories on average in just 20 minutes. Swinging the kettlebell works muscles in a way that weight machines and barbells can't. Start with a light kettlebell -- 8 to 15 pounds for women and 15 to 25 pounds for men. Form is critical to prevent injury, so ask a trainer to show you how to properly use them.

Jumping Shoes: Low-Impact Cardio

Putting a spring in your step can take stress off your joints. Kangoo Jumps are boots with springs on the soles -- like grown-up moon shoes. You can jog or do aerobics in them, burning calories while being gentle on your body. But if you are pregnant or have high blood pressure or balance problems, stick with springless shoes.

Boot Camp: Back to Basics

This is basic training without a drill sergeant sneering and shouting in your face. There’s no fancy equipment -- just a series of push-ups, squats, kicks, other calisthenics, and aerobic movements. You’ll burn about 10 calories a minute or 600 an hour. The payback: total-body fitness.

Aerial Yoga

Yoga blends are a huge fitness trend. This one's name says it all: You do variations on traditional moves while hanging in "hammocks" suspended from the ceiling. The weightless poses relieve aching joints and stretch muscles as well as strengthening your core. For other fun twists, try Cy-Yo, a yoga-indoor cycling combo, or YogaFit, which includes squats, sit-ups, and other fitness moves.

Floating Yoga: Balance on a Board

Put the serenity of a still lagoon together with the challenge of balancing on a paddleboard and you get floating yoga. Doing yoga moves on a paddleboard, which is larger than a surfboard, takes muscle control to keep from making a splash. The board is either anchored down or tied to a buoy to keep you from getting swept away by the experience.

Exergaming: Aerobic Play

Who said playing video games turns you into a couch potato? You can burn as many calories exergaming as working out at the gym -- about 270 calories vigorously dancing or 216 calories virtual boxing in a half-hour. Exergaming is a great way to get kids moving. And slower-paced activities can help older adults be less sedentary.

Boxercise: A Workout Knockout

Among exercises, boxing is a knockout -- delivering agility, balance, muscle tone, strength, and cardio benefits. Sparring also improves hand-eye coordination and mental agility. Boxercise, which started in England, includes dancing, skipping, shadow boxing, kicking punching bags, and more. Be sure to protect your thumbs and knuckles, and consider wearing shin supports.

Hulas: Whittle While You Work Out

If the last time you swung a hula hoop was in fourth grade, it's time to give it another whirl. It's easier to swing the new weighted hula hoops than the flimsy plastic ones. And hooping can burn more calories than step aerobics and raise your heart rate as much as cardio kickboxing. It works your waist and core muscles, and can tone your thighs and biceps.

Weighted Vests: Power Walking

Adding weight may be the simplest way to boost your workout. Extra weight raises your heart rate and makes you burn more calories. Instead of walking with hand or ankle weights, which can strain muscles and joints, consider wearing a weighted vest. Choose one that is 5% to 10% of your body weight.

Techno Trainer: An App for Exercise

What if you want help losing weight and getting fit, but you can't afford a personal trainer? No problem. Apps can help too. Fitness trackers such as the Fitbit and GoWear Fit measure your steps, calories burned, and the calories you eat. They can even monitor your sleep. The information can also be downloaded and tracked on your computer. There are also apps that explain proper exercise form, a common problem among beginners.

Finding a Good Trainer

A trainer can help you get more out of your workout. Choose a trainer with experience in the type of workout you want to try. Look for someone who is certified by an accredited program, such as the American College of Sports Medicine, the American Council on Exercise, the National Academy of Sports Medicine, or the National Strength and Conditioning Association.

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