Want to know the difference between an amateur and an expert? An expert has mastered the basics.

Over the next few months, I'll help you master the basics one by one, so you can get the highest return on your investment of time and effort in the gym. We started with the movement that I consider the most fundamental exercise of all time: the deadlift.

While I believe the deadlift is the most productive strength exercise ever, a very, very close second goes to the squat. It takes the hips and knees through a greater range of motion than the deadlift, and is directly transferable to running and jumping.

In other words, it is absolutely indispensable for athletes.

But even non-athletes should devote time to learning to squat properly. Very few exercises stimulate and preserve as much muscle tissue as squats, making them particularly valuable for older folks. To paraphrase a colleague: "the more you can squat, the longer it will be before you can't get up off the toilet by yourself."

Now that's a valuable proposition.

Unfortunately, misinformation abounds regarding squats. Some people (even trainers!) say they're bad for your knees and/or spine. The real issue is that ANY lift or exercise done carelessly can be dangerous. When you undertake learning to squat (or re-learning if it's been awhile), take your time working through the progressions demonstrated in the video below. Investing a few weeks in ingraining good form will set you up for years of productive training!

The video below details five squat variations, suitable for everyone from beginners to more experienced lifters. No matter which variation you use, there are a few important cues to keep in mind:

  1. Initiate the squat by pushing your butt backwards, NOT by pushing your knees forward. Keep your heels planted at all times.
  2. Maintaining as upright a posture as possible (chest lifted, spine neutral), descend until the hips are lower than the top of the knee joint. It might take time to develop the strength, flexibility, and control to go this low. That's OK! Don't rush it. Take your time building strength in whatever range of motion you can control. It will increase over time.
  3. Ascend by driving your heels down into the floor, ensuring everything comes up together: your hips, chest, and shoulders.
  4. Lock out each rep fully: legs straight, butt clenched.

Marshall Roy is the owner of RISE gym, a private strength training facility in King of Prussia, which offers 1-on-1 training and small strength classes. He is the 2014 "Best of Philly" personal trainer, and you can access 20 of his innovative kettlebell workouts and 48 video demonstrations for free at KBformula.com.