Ah, the delights of the holiday season: the crisp weather, the cozy fires, the family festivities and the sumptuous feasts. But, with all the merriment come special challenges -- to our waistlines. "The holiday season is an extremely busy time, and exercise often is reduced or dismissed completely," says Jennifer Schumm, a certified personal trainer and lifestyle and weight-management consultant from Denver. "Yet, with all the extra calories being consumed, this is not the time to minimize exercise. If anything, exercise should be maximized and prioritized." But how can you be expected to squeeze in workouts on top of everything else? Rest assured, it can be done. Here's how to maintain your shape over the holidays -- no matter what the situation -- so you can hit the ground running (rather than waddling) come Jan. 1.

Problem: Bad weather

Solutions: Layer up. Winter weather can deter even the most devoted exerciser. But dressing smarter makes workouts safer and more comfortable. "By dressing correctly, you can create a micro-environment of comfort and protection around your body," says David Musnick, M.D., editor and co-author of Conditioning for Outdoor Fitness (The Mountaineers, 1999). The secret is to wear several layers to regulate heat and moisture, peeling them off as you get warm. The layer closest to your body should be thin and made from a "wicking" material, such as CoolMax, that draws moisture away from your skin so it can evaporate at the surface. The outer layer should shield you from the wind, rain or snow.

: Adjust duration and location. Running on a hushed winter morning can be cathartic, but working out in low temperatures for too long can cause a variety of problems, especially if you have poor circulation or exercise-triggered asthma, notes Musnick. Follow this rule: When it's cold or wet outside, keep workouts to under 40 minutes; when it's cold and wet, move your workouts indoors.

Problem: A packed schedule

Solutions: Be proactive. To win the battle of the bulge during the holidays, you must have a strategy. Here's a simple one: For the entire month of December, enter four workouts a week into your personal organizer -- each 30-45 minutes in duration -- and tag them as "high priority" appointments. Schedule these as early in the day as possible; most people are less likely to forgo morning exercise.

- Keep it simple. The more barriers that exist between you and your workout, the less likely you are to do it, particularly at this time of year. Initiate adjustments now that will make exercise easier to do later, such as shifting gym workouts to your home, investing in a new exercise video or opting for lower-maintenance activities such as running, walking or hiking.

- Do more in less time. "Interval training is extremely time-efficient, because it burns a lot of calories in a shorter amount of time," says Miami-based Minna Lessig, "Health Watch" fitness contributor for CBS' The Early Show. By alternating bursts of high- and low-intensity cardio, a 145-pound woman can burn 200-250 calories in just 20 minutes. Just be judicious with interval training: Perform these kinds of workouts no more than three times per week, and be sure to monitor your heart rate (see below) so that you don't overtrain and tire yourself out.

Problem: Travel

Solutions: Get packing. If you're heading out of town for the holidays, a little pre-trip planning can go a long way toward avoiding extra pounds. "Pack workout attire and equipment such as resistance bands and even an exercise video," suggests Schumm. If you've gone to the effort to haul them, chances are better you'll use them.

- Set the bar a little lower. Trying to follow an extremely ambitious exercise regimen while traveling may not be realistic. So, simply strive to do as much as you can. "You don't have to do your full workout while on the road," says Princeton, N.J.-based Ed Hewitt, features editor and columnist for the online travel guide "The Independent Traveler" ( Even a gentle 20-minute session will help you maintain your fitness level, and you can get back on a more rigorous schedule when you return home, Hewitt adds.

Problem: Exhaustion

Solutions: Make a move. Chances are you'll be feeling fatigued more frequently this month -- but sometimes our bodies aren't tired; our minds simply convince us they are, says Kim Mulvihill, M.D., medical reporter for KRON 4 News in San Francisco. So, try this: When you're feeling too weary to work out, just begin moving, and let your body determine the duration and the intensity. You might find you're capable of more than you thought.

- Monitor your heart rate. Exercise should perk you up rather than wear you out -- but working at too high an intensity can backfire and rob you of the energy you were aiming for. To that end, a little technology can help guide the way. "Using a heart-rate monitor to exercise in appropriate 'intensity zones' will ensure that you don't overdo it," says Mulvihill. The American College of Sports Medicine recommends that, to maximize fat loss and minimize fatigue, exercise intensity should remain within a range of 60-90 percent of your maximum heart rate (MHR). To estimate your MHR, simply subtract your age from 220. Following these guidelines will make it easier to burn excess fat without burning out, which is a sine qua non for maintaining your shape -- and your sanity -- over the holidays.