The sheer impact sustained by the knees, hips, and spine from burpees, box jumps, and the like is downright outrageous.

Sure, box jumps can be a great way to activate some fast-twitch muscle fibers before heavy squats or pulls, but don't get confused – this type of intelligent, goal-oriented programming isn't the problem.

The problem is flailing up and down a 24-inch box for 15 consecutive minutes while sustaining contusions to your shins and thinking you've done something productive.

Movements involving a huge amount of external force production need to be programmed with caution, which is rarely, if ever, considered. Any time you depend on your muscular system to generate high amounts of force and tension to complete a physical task, you'd better respect the damn process.

This isn't the type of movement you just grind through. Due to the impossibility of repeatedly performing a plyometric movement without a mechanical breakdown of form and technique, the likelihood of suffering an injury becomes significant.

There's no argument that burpees can leave you with your head in the garbage can. In our ignorant fitness society, where the value of an exercise is determined by how crappy you feel afterward, burpees have been elevated to the single best form of conditioning ever conceived!

Congratulations CrossFit, your wicked hard programming methods have crept into commercial gyms, and physical therapists thank you.

Do This Instead – Speed Squat

The speed squat eliminates ground reaction forces that can put a pounding on your joints, while recruiting muscle fibers more efficiently than its jumping counterpart.

Reducing joint stresses while increasing multiple forms of muscular stress leads to something called "gains."

Rocky Balboa is responsible for half of our nation's total knee replacement costs over the past three decades. Because of the Italian Stallion, men and women across the world gravitated toward the stairs for exercise.

I mean, what's more badass than sprinting up stairs and looking down to admire your conquest? How about joint health and the ability to walk? It's a good thing Rocky is fictional, or he would've been limping into the orthopede's office pleading for the knife at the age of 46.

For most people, adding incline and stairs to an already painful gait is an expensive recipe for disaster. If you plan on using stairs conservatively in your training (less than once per week), you may be able to make it through this joint minefield. If not, you may be in for a long, painful ride that doesn't involve a final round knockout of a biochemically engineered Russian.

Your effort to relive your high school football days by running stadium stairs will result in repeated trauma to the knees and lower back. After a while, your articular cartilage will resemble ground beef rather than a functional shock absorber. Time to limit that punishing damage!

Do This Instead – Strict Single-Leg Step Up

If you're capable of doing these without cheating, they can be one of the most metabolically torturous leg builders in the gym.

Do these in a non-alternating fashion and make them extra challenging. When you feel your quads start to spasm, when the sound of your heart pounding at maximal rate is muffling the sound of your breath, go up 5 pounds in each hand.

Hitting all fours and putting your grill in the grass has become the latest conditioning craze. Crawling is the most primitive and foundational movement patterns people master to eventually walk on two legs. Crawling links up our body segments to enhance both mobility and stability to create our first form of locomotion.

This all sounds great in theory. Get back to the basics with an ass-kicking workout, right? Not so fast. It only sounds amazing until people actually attempt to drop down on their hands and knees and start plodding away!

With our everyday postural demands at an all-time high and our general level of body composition and movement abilities at an all-time low, the once natural crawling pattern may as well be a 150-kilogram snatch. You're not going to be able to do it at first, and even if you are, it'll crush your body in the process.

While the bear crawl involves ample hip and pelvic mobility to maintain a neutral spine, not many people meet these prerequisites to make the crawl a safe and effective conditioning method. Decreased mobility translates to destructive stresses through the adjacent joints: the five segments of your lumbar spine.

This is why your back hurts after bear crawling your butt around the gym. It's just weak movement execution!

The bear crawl is no better for your shoulders than it is for the lower back. When programmed for maximal speed or time, as most "coaches" teach, heavy compressive loads and positional malalignment becomes an orthopedic nightmare.

Do This Instead – Controlled Developmental Crawl

The focus of crawls should be to own your mechanics while relearning an elementary movement pattern.

If you're worried about not getting your heart rate up while crawling the proper way, it's obvious you've never tried this exercise. Slow and controlled movements will smoke you just the same as your uncontrollable ass-up hand waddle, minus the post-crawl pain!

Proper training should do a few distinct things for you:

1. Training should simply yield some positive results.
2. Your chosen form of exercise should be a tolerable form of physical activity that can be maintained for the long run.
3. Most importantly, it shouldn't seriously damage your body.

I'm not talking about your quads burning after a set of squats. More like burning nerve pain shooting down your legs and causing numbness after your horrific kettlebell session. Lesson one: Do no harm. You only get one body. Better treat it right.