Beth Shaw is the President of YogaFit, the world’s largest yoga training school. Her third book, YogaLean, will be released this fall, and offers a holistic approach to eating healthy, losing weight, and keeping it off. Find more tips at her personal site desiplay.com.

At the end of a summer, as fall approaches, we can sometimes feel busier than any other time of year. We tend to work too much and exercise too little, assuming that unless we have an hour or more to spend at the gym on a regular basis, it’s pointless to even try to get in shape.

Well, here is my solution to that problem, and I think it’s a good one: Take just 30 minutes out of your busy day, and go on a gratitude walk. Make it special. Make it an event that you look forward to. View it as an opportunity for positive reflection. When you walk, make sure you move at a fast pace and reflect on things in your life that you are grateful for.

I am fortunate to live in both exciting New York City and sunny Southern California. (Being bicoastal is really a joy!) But this walk can be done anywhere—in the city or on the countryside. It can even be done on a treadmill.

A couple of month's ago, Men's Health asked Alwyn Cosgrove, C.S.C.S.—one of the world's top trainers—to create a cutting-edge fat loss program forMen's Health. And, of course, he obliged. But a curious thing: One of the workouts in the plan featured just two exercises.

That's right: When asked to create a super-effective, calorie-torching routine, Cosgrove gave us a workout that had readers do only a dumbbell swing and a squat thrust. This confused some folks, who wondered, "How can you lose fat with just two exercises?"

Kettlebell (or Dumbbell) Swing
Bend at your hips, and hold a kettlebell (or dumbbbell) with both hands at arm’s length in front of you. Now, rock back slightly and “hike” the kettlebell between your legs. Then squeeze your glutes, thrust your hips forward forcefully, and swing the weight to shoulder height. Allow momentum to swing the weight—you're not trying to actively lift it with your arms. Reverse the movement, so that you swing the kettlebell between your legs again. Make sure you don't round your lower back at any time; it should stay naturally arched when you bend at your hips. Continue to swing back and forth. Watch the video below to see fitness expert David Jack show you how to do the kettlebell swing with perfect form:

Of course your twenties are a time to live it up, explore your options and do what you're crazy about. But they're also a time to get into the habit of, well, practicing healthy fitness habits—because doing so will ensure that you're healthier later on, according to a new German study published in the journal Psychology of Sport and Exercise. (See also: 30 Health Choices You Should Make Before You Turn 30.)

For the study, researchers tracked over 500 adults for over 18 years, and found that people who were healthiest in their young adult years were also healthiest over time. So we reached out to some fitness experts to find out their best tips for what 20-somethings should pay attention to. Your mission? Start doing all of these things—right now. Your future self will thank you!

The experts we spoke with: Greg Justice, an exercise physiologist and author of Mind Your Own Fitness; Ellen Breeding, an exercise physiologist at AYC Fitness in Kansas City; Irene Lewis-McCormick, certified strength and conditioning specialist and author of A Woman's Guide to Fitness & Strength