Several weeks ago, I was invited to attend a complimentary Core Fusion Barre class at Exhale in Boston. I heard awesome things about Core Fusion, so I was excited to finally give it a try. The workout combines core exercises with Pilates, yoga, and ballet to stretch and tone muscles.

After a brief warm-up, the class started with some planks, push-ups, reverse push-ups, and then we moved onto upper body work using small hand weights. Using the weights, we did small, controlled movements for the triceps, shoulders, back, and biceps, and wow, did it burn! The next part of class focused on the quads and glutes, so there were lots of pliés, pulsing squats, and leg lifts—I pretty much died during this part of class. My quads and glutes were absolutely burning with pain, and I had to stop often to rest. I actually felt like a big baby taking so many breaks, but my legs just could not handle it. I didn't think a barre class would be so difficult, but it kicked my butt!

I generally think of myself as a fit person, but Core Fusion was definitely a challenge, which is why I liked it so much. I love classes that really push me out of my comfort zone. They make me want to work so much harder. Even though I really enjoyed Core Fusion, I could foresee this type of workout getting sort of repetitive with the same type of movements and format to every class. It's a workout that I'd like to do a few times a month, but not as a replacement to my typical workout several days a week. This brings me to my favorite Feel Great Workout: CrossFit.

About six months ago, I took my first CrossFit class, and I loved it immediately. And I'm not alone! It's never the same thing twice and many of the exercises (Burpees, Mountain Climbers, and rope climbs) remind me of those I did as a kid, so the workouts are fun and exciting. Plus the "constantly varied, high intensity, functional movements" constantly challenge and push me, so I've seen some serious results, which makes me stick to it. (I typically attend 3-5 CrossFit workouts each week.) Here are just some of the changes I've seen:

I’m faster and stronger. I recently ran a 10K in 50:12 (8:04 pace), which is a whole 4 minutes faster than my previous 10K time. Also, I could never do rope climbs in gym class as a kid, but after 6 months of CrossFit, I can do multiple rope climbs in a single workout. I can also do unassisted chin-ups (something I thought possible) and deadlift 200 pounds!

My back is stronger. I have pretty bad scoliosis, so, over the years, I’ve suffered my fair share of back pain and hip injuries (related to the misalignment). CrossFit has really strengthened my lower back and core, so now I rarely experience pain anymore.

I’m more confident in my abilities. I still remember thinking I couldn’t do a Box Jump on my first day of CrossFit. Now, I can do all sorts of neat things, like Power Cleans and Double-Unders (where you pass the jump rope twice under your feet in one jump), which has really boosted my confidence in my physical abilities—the best kind of motivation!

My sugar cravings have vanished. I’m not sure how to explain this one, but I just don’t get intense, uncontrollable sugar cravings nowadays. I still eat sweets because I love them, but I don’t need them, and there are many times I've skipped dessert altogether. I assume the change is due to paying closer attention to what I’m eating since I began CrossFit. I’m eating more "real" food that satisfies me, so I don’t crave sugary things as much.

And oh ya, my jeans are loose. I've pretty much maintained my weight since starting CrossFit, but I've toned up quite a lot. My jeans fit great and I can’t wait to show off my buff arms in tank tops this summer!

More: Read Tina's daily food and fitness blog, Carrots 'N' Cake.