If the path to a flatter stomach were paved with crunches, every person with a gym membership would sport a six-pack. "But crunches only flex your trunk," says Todd Durkin, C.S.C.S., author of The IMPACT! Body Plan and creator of The 28-Day Fat-Torch. "To sculpt a stronger, more chiseled core, you need to train it the way it functions." Or, more specifically, all the ways it functions.

See, the more than two dozen muscles between your hips and shoulders are what allow you to bend and rotate your torso. They also stabilize your spine as you mow the lawn, carry unruly toddlers, do pushups, spike volleyballs, and otherwise go about the motions of daily life. That's why trying to build a solid center with only crunches, which target your rectus abdominis (the six-pack muscle), is like trying to build powerful legs by focusing only on your quads. The result is all show and no go.

Update your ab routine with these two exercises. "They'll challenge your core from every angle, making you stronger in everything you do," says Durkin. They'll also give you something to bare at the beach. For the best results, pair these core-sculpting moves with Durkin's 28-Day Fat-Torch, a metabolic training plan that will strip away the fat covering your abs for good.

You're dropped off in the middle of nowhere on the Russia-Finland border. Sure, the scenery is pristine and the air is fresher than anything you've ever breathed. But you aren't there to sit back and soak in the breathtaking scenery. You have mountains to climb, rapids to kayak and caves to spelunk. You're taking on the Red Fox Adventure Race, and you're going to need those breaths.

Extreme adventure races, like Tough Mudder, Spartan and Warrior Dash, have taken the American fitness community by storm. But this is another, more complicated animal. Adventurers have been facing the Red Fox, Russia's most popular and prestigious adventure race, for ten years. The tenth anniversary race was held June 10-12 in the beautiful Karelia region. Many of the popular races in the U.S. involve man-made obstacles, like barbed wire crawls and fire pits. But the Red Fox Adventure Race uses the unforgiving topography of the region to challenge competitors, who race in teams of two or four, in kayaking, white water rafting, spelunking coastering, mountain biking and rock climbing.

Organizers expected even the top participants to take at least 36 hours to finish the course, which takes place over about 186 miles and numerous checkpoints. But the winning team of Red Fox 2012 -- Igor Klepcha and Irina Safronova -- finished in less than 25 hours.

"We rode bikes, pedaled in the river and in the White Sea and climbed mountains, and that all happened in 24 hours," Klepcha told Russia Today.

More than one third of the 64 teams never reached the finish line, which just goes to show, you don't need fire pits to make a challenging race. Sometimes you don't have to change a thing about the terrain, and nature will provide the most unforgiving challenge.

By DualFit.com

High Intensity Interval Training (HIIT) is a wildly popular method of exercising that focuses on bursts of intense activity followed by short periods of rest and recovery. A typical HIIT workout consists of roughly 60 seconds of high intensity training and 90 seconds of rest, and then repeated for 15 minutes or so.

This style of workout has been proven very effective at increasing cardiovascular health, and studies have shown that in just two weeks of HIIT, young men developed significant increases in resistance to insulin, helping prevent Type II Diabetes. Another benefit of HIIT is an increased capacity for oxygen in your lungs. If you train via HIIT, you will find it much easier to climb a flight of stairs or go on a light jog without becoming winded.

If you're looking to get "swole," then you might be overlooking HIIT as a method for bulking up. Studies have shown that in the 24 hours after a HIIT workout, the body produces 450 percent more human growth hormone than normal. HGH is the stuff that encourages your body to build lean muscle mass. HIIT has also been shown to increase your metabolism substantially in the 24 hours following the exercise. Anytime you have the opportunity to increase your metabolism, do it. It not only aids in weight loss, it keeps the body healthy on the inside as well.

Find the routine that is right for you and do it! The faster you begin, the faster the results start pouring in. You will need a heart rate monitor to perform these exercises with maximum effectiveness. For the strenuous part of the exercise, your goal should be to have your heart pumping at 85 percent of its maximum rate.

To find your maximum heart rate, subtract your age from 220 and you will have a decent estimate. Training beyond 85 percent of your maximum heart rate increases the risk of injury without providing any added benefit. Without further ado, let's "HIIT" the gym:

HIIT On A Cycle
This one has sets that are a bit longer than most HIIT routines but is good for those looking to emphasize Lance Armstrong-style leg endurance. You will find yourself biking the French Alps in no time.

Routine No. 1
-- Do a three-minute warmup period at medium pace with no incline/resistance. (60-80 RPM)
-- Thirty seconds in, increase the resistance and add a level of steepness but keep the RPM above 80.
-- Keep repeating until you cannot hold a pace above 80 RPM.
-- Rest for two minutes and repeat as desired. Your goal should be to work up to a 15-minute cycle workout. The 15 minutes should include the five-minute warm-up and cool-down.

Routine No. 2
-- Bike for five minutes to warm up.
-- Cycle at maximum intensity for one minute.
-- Coast for one minute.
-- Repeat the maximum intensity set for one minute.
-- Rinse and repeat for 15 minutes with a five-minute period of light activity at the end.

The "Old Fashioned"
This one combines the earth and your feet to create a powerful workout that will have your glutes set ablaze. In other words, we will be sprinting.

-- Do a light jog for five minutes to warm up.
-- Sprint for thirty seconds (if you're new) or one minute (seasoned vet) at near maximum intensity.
-- Go back to a light jog for one minute to a minute and a half.
-- Repeat for 17 minutes, at the end of your routine do a five-minute cool-down.

Row Your Boat
Whether you are on the row team at Princeton or just want to build back and shoulder strength while maintaining cardiovascular health, try this HIIT exercise.

-- Warm up for three minutes or so.
-- Immediately after the three minutes are up, go hard for 60 seconds.
-- Take a 60-second break.
-- Do another 60 seconds of maximum intensity.
-- Repeat for 17 minutes while allowing for a five-minute cool-down.

The Butt Routine
For this one you will need either a Stairmaster or a set of stairs that takes you roughly 60 seconds to climb. Your butt will be a masterpiece after doing this for a couple of months. Since we are going to be putting a lot of stress on our legs and glutes, let's make sure to stretch before with this one.

-- Ascend and descend the stairs for five minutes or so. Do this at a light pace, as this is our warm up.
-- After your warm up, climb the stairs or Stairmaster at maximum intensity for 45 seconds to a minute.
-- Rest for one minute. If you are really looking to build those legs, do some light lunges during your rest.
-- Do another set of high-intensity stair climbs.
-- Repeat for five minutes, then do a five-minute long cool-down (continuous and light.)

The One That No One Likes
Most people do not like doing pushups. It's a hard exercise, and if you don't have a lot of upper body strength, it can be especially strenuous. Perform this HIIT exercise if you want to build upper body strength while maintaining cardiovascular excellence.

-- For this one, we are going to break the mold and warm up with five minutes of jumping jacks. You will feel like a kid again.
-- After your warm-up, plop down and pound out a set of pushups at maximum intensity for 60 seconds.
-- Take a minute and a half break.
-- Keep doing sets of pushups/breaks for five minutes.
-- Do another five minutes of light jumping jacks for your cool down.

The Core Crusher
This one is a staff favorite here at Dual Fit. Our favorite lifting routines call for a rest day consisting of cardiovascular exercise and abdominal work. This high intensity interval training routine combines the best of both worlds. Utilize this workout if you are looking to build up core strength while maintaining cardiovascular fitness.

-- Much like with the pushup routine listed above, we will start by doing a five-minute light jog to warm up.
-- Head over to your gym's power tower (or captain's chair) and do 60 seconds of full-out, high-intensity knee raises. You will feel the burn, rest assured.
-- Rest for 60 seconds.
-- Do another set of intensity-filled knee raises and rest. Repeat for five minutes.
-- Do a five-minute light jog to cool down.

Feel The Greatness
As you can see, HIIT is very versatile. You can mix and match and even create your own routines. The main emphasis for someone new to HIIT should be a routine that goes hard for 60 seconds and then breaks for a minute to two minutes, depending on the exercise involved. As you get accustomed to HIIT, you can lower the work to rest ratio from 3:1 to something like 2:1 and eventually even 1:1. Just make sure that you are ready before jumping to the next level.

Since you are going to be performing these exercises at a very high rate of speed and intensity, you will want to make sure to stretch thoroughly before the workout. You know how easy it would be to pull a hamstring during sprints or to pull a quad on the cycle without stretching and warming up? Very easy. Since we are going to be pushing ourselves to the maximum, warm-ups and cool-downs are extremely important as well.

Warning
If you have heart disease or a family with a history of heart problems, you will want to consult a doctor before beginning a high intensity interval training program. If you smoke, are sedentary, are overweight, or are over the age of 60, then it would be wise to consult a doctor before jumping into an exercise like this. If you are out of shape, start out slow and gradually work your way up to a fitter, healthier you.

By DualFit.com

Often overlooked as a necessity to many, the calves are an essential component in building stronger and more proportional looking legs. Formally called the gastrocnemius, the calf muscle is located on the back of your leg between your knee and ankle.

The calf muscle has two heads called the medial head and the lateral head–diametrically opposed to the gastrocnemius and soleus. This muscle is primarily responsible for the plantar flexion of the ankle and the flexion of the knee. There's another muscle that's often mislabeled as being part of the calf muscle and that's the soleus. This muscle is located outside of the gastrocnemius, also assists in the plantar flexion of the ankle, and plays a significant role in most calf exercises.

Seated Calf Raise
The seated calf raise works both the calf muscle and the soleus. To begin, sit on the machine and place your feet on the platform below. Make sure only your toes are on the foot platform while your heels are hanging off. There's an adjustable thigh pad that needs to be lowered until it's firmly positioned against your thighs. On top of the thigh pad there are two hand grips to hold on to while performing the exercise.

Once you are properly positioned, push up on your toes so the weighted lever is lifted off its rack. Then reach down to the side of you and pull the safety lever so that the rack is moved out of the way. Now slowly lower your heels as you begin to feel the weight on your calves as they become fully stretched. Next, push up on your toes as high as you can go and briefly pause at the top before returning back down. Repeat this movement for the desired amount of sets and repetitions.

Once finished, push up on your toes and then pull the safety lever back into its original position so you can rack the weight. Make sure you keep the movement slow and under control. Do not perform the repetitions at a fast pace as it could lead to ankle or calf injuries.

Standing Calf Raise
Standing calf raises have a few variations but the most standard method of this exercise is using a standing calf raise machine. Adjust the shoulder pads to compensate for your height. Step up onto the foot stand with your toes and the balls of your feet on the foot stand, leaving your heels hanging off. Make sure your shoulders are firmly placed under the shoulder pads, your torso is straight and your knees have a slight bend.

To begin, push upward on your toes and momentarily pause at the top of your movement. Slowly return the weight down until your heels are hanging off the foot stand. Repeat this movement for the desired amount of sets and repetitions. Always keep the weight under control throughout the entire movement. Never lock your knees during this exercise as it could lead to injury. If you suffer any lower back pain then choose another calf exercise as this one places significant pressure on the lower back.

Dumbbells and barbells can be used instead of the machine for standing calf raises. The movement is performed the same but you have to find an elevated foot stand or an aerobics step to allow for your heels to hang off.

Leg Press Calf Raise
The leg press calf raise involves the usage of a standard leg pres machine in which you push upward at a 45 degree angle. This exercise can be done with one leg or both legs. To begin, sit in the machine with your back and head against the back rest. Your upper body should make a 90-degree angle with your legs as you position sit down. Next, place your toes and the balls of your feet at the bottom of the foot platform. Push the weight up with your toes and release the safety levers which will place all of the weight on your feet and legs. Do not lock out your knees when pushing the foot platform as this could lead to possible knee injuries.

Slowly lower the weight until your heels are lowered and your ankles are bent. You will feel a significant stretch on the calves at this point. Repeat this movement for the desired amount of sets and repetitions. Always keep the weight under control as you slowly perform the exercise.

More From DualFit.com:
-- Interview: 2009 Fitness America World Champion Tiffani Bachus
-- HIIT: High Intensity Interval Training
-- 5 Shoulder Sculpting Exercises
-- The Truth About Organic Foods