The ONE Thing To Do When You Can't Go To The Gym

If you look at any gym's timetable, pretty much every spin class and bootcamp workshop is a full hour long. Then there are those classes featured on your yoga studio's website that hold people hostage for 90 minutes. Even I, a devoted yogi and Crossfitter, wonder how people out there have the time to attend these extended sessions, because sometimes even my day gets so jam-packed that I can't sneak in a workout as an instructor. I always cringed when I heard fellow fitness instructors say that if a person wants to work out, they'll make the time to do it. Well, anybody whose career isn't centered on exercise knows that this is not always the case. We just get really freakin' busy from time to time, and there's nothing wrong with that. So what can you do if you want to get many of the benefits of exercise, but have less than five minutes for a workout?

If you know your calendar is overflowing and you won't have time to hit the gym, try this on for size: do a HIIT exercise. High-intensity interval training (HIIT) is a type of workout that has recently become extremely popular, trendy even, because of its time-saving and fat-burning qualities. It goes like this: You alternate a few high-intensity moves with short periods of rest. You can choose how long you want the session to be, and sometimes they're as short as four minutes. Yep, four minutes.

The American College of Sports Medicine Annual Meeting, in a 2011 study, found that this cardiovascular routine can improve your aerobic capacity just as much as 6-8 weeks of class endurance training, like long-distance running or cycling, can. When you're moving your body this quickly, your muscles can't get as much oxygen as they would like, which is a good thing, because the result is excess post-exercise oxygen consumption (EPOC). EPOC is an increased rate of oxygen intake once the workout has ended, and it helps you burn calories and reap the other benefits of exercise long after you've wiped off the sweat.

Getting high-speed blood pumping through your veins doesn't take long — and it definitely doesn't take a whole hour. Pick one or a few of the movements below; do just a few rounds, 30 seconds on and 10 seconds rest. Remember, it's about speed! Try to do as many as you can in the small window you've got, with good form of course. You'll feel the burn in no time — and give yourself a much-needed burst of energy.

1. Mountain Climbers

You can do these anywhere, on any surface, and if you commit to picking up some speed, you'll be surprised at how quickly you get out of breath. Don't forget to contract your abs throughout, which will tone your core and help you bring your knees a little closer to the chest.

2. Split Leg Squats

You don't even need shoes to do this one (just be careful that you don't stub your toes if you're on hardwood floor). It takes a little practice at first, because you might initially feel like you're going to lose your balance. But your thighs will thank you for your hard work later.

3. Squat Jumps

If you really want to add a little extra spice to this one, as you're coming out of the squat, jump high enough so your knees pull into your chest. Phew.

4. Burpees

These things never fail to make me sweat — and curse. They're a lot harder than they look, and they truly are a full body workout. Be sure you keep your elbows in during every push-up to protect your shoulders.

5. Jumping Jacks

They seem too easy, right? Trust me, you won't find them so simple after a couple rounds. Because it's not a movement that runs the risk of injury, you can afford to really pick up the speed. The faster you go, the higher you'll feel afterwards.

Yes, I know this is all still exercise, but remember, even if you do this for just four minutes, it can count for a whole lot.

Images: jolopes/Fotolia. Videos: ehowfitness, XHITdaily, Howcast (3)/YouTube