Yes, mindlessly running on a treadmill while watching the news on your gym's TV can be a total snooze fest. But dancing in a Zumba class, rock climbing, and paddle boarding are the exact opposite of dull -- and they still count as exercise.

The trick is to continually search for workouts that are fun so you actually enjoy exercising. Aside from trying new classes at the gym, Williamson says, "I browse YouTube a lot to see what new stuff folks are trying out; it's interesting to see what some people do with little to no equipment."

But even if you do stick with your regular routine, Barry Jay, co-founder of Barry's Bootcamp, says you can create a fun environment to motivate yourself to get through even the most mundane routine. "Lighting, amazing music of all genres, and humor can help you push through a workout," he says.

Another way to keep exercise from getting old is to add in the element of competition, says Dr. Amir Vokshoor, MD, a neurosurgeon who studies the brain in relation to athletes at the DISC Sports and Spine Center in Marina del Rey, Calif. He explains that after awhile, anything we do repeatedly (like lifting weights or 30 minutes on the elliptical) becomes easier, and that's when our brain starts to resent the exercise. "When an exercise isn't fun anymore, the brain needs surprises, risk, and danger," says Vokshoor. "Competitive sports can give you that risk and danger."

If the thought of joining your company's softball team sounds like less fun than an all-day root canal, that's OK. Marie-Josee Shaar, a personal trainer and author of "Smarts and Stamina," says your workout should play to your strengths.

"Research shows that we are much more motivated, resourceful, and resilient in an area of strength than in an area of weakness," Shaar says. Like taking charge? Lead a morning group run in your neighborhood. Does kindness drive you? Train for a cause, or buddy up with someone else who also needs motivation, Shaar says.

How do you know when you've found the right workout? "The right exercise should be relaxing, get you in a hyper-aware state from endorphins, get your mind wandering, make you feel good, vital, and youthful, and leave you sore, but a good sore," says Vokshoor.

Personal trainer Steve Cabral says the best way to combat this frustrating feeling is to set yourself up for a "quick win." By starting off strong -- with a super-healthy diet and perhaps some boot camp-like fitness classes -- you could lose three to five pounds in your first week, which should certainly get you excited to continue.

And when you hit those inevitable plateaus, there are a few ways to keep yourself going. Suzie Cooney, CPT, a certified personal trainer and owner of Suzie Trains Maui, says to try visualization while you're working out. "I want [my clients] to 'see' a healthy and strong body," she says. "I want them to 'see' themselves crossing the finish line as we're spinning on the bike. Visualization training is incredibly helpful." Focusing on your goal is a much better way to push yourself during a workout than focusing on how fatigued you feel or the fact that the scale hasn't moved in a week.

Get excited, because it turns out cheating on your diet can actually help your workout. Cabral says he recommends his clients have a weekly cheat meal (where you can eat whatever you want). Not only does this give you something to look forward to each week, but he says a cheat meal releases the hormone leptin, which tells the body you're not starving. The result? It can actually boost your metabolism and make you lose more weight over the next week. Just don't hop on the scale after that pizza: "You may initially go up in pounds from water weight and salt retention, but by the end of the week you'll be lower," says Cabral.

If you're feeling too sore to move the day after a workout and can't even begin to attempt another minute of exercise, it's time to rethink your strategy. Shaar says sometimes it's beneficial to end a workout a little prematurely. "It enables me to end on a high note while I still feel very energetic, it enhances my post-workout glow, and it truly makes me look forward to my next session," she says.

Spangler says this method is an especially great idea when you're just starting out. "People start giving 100 percent and then they burn out quickly," Spangler says. "You're better off starting slowly with something like strength training or a yoga class [if you're not used to exercising]. Then build up your stamina and try more challenging workouts."