I've looked around but there seems to be a lot of variety out there. Is there a widely accepted "best" set of instructions or video for doing squats correctly?
First, you need to decide what type of squat you want to do:
- Front squat (quad focussed, upright torso)
- Low bar back squat (balance between quads and hamstrings, torso tilted forward more)
- High bar back squat (somewhere in-between the two)
The low bar back squat with a depth that brings the upper surface of your thighs slightly below parallel is well described by Mark Rippetoe in his book, Starting Strength. Some material is available online, also:
- http://startingstrength.com/articles/squat_rippetoe.pdf: This goes over the differences between front, high bar and low bar back squats, and gives some good reasons for choosing the low bar back squat over the other alternatives.
- http://vimeo.com/30763907: This explains proper positioning of the bar for a low bar back squat.
Starting Strength by Mark Rippetoe is widely accepted as the best instructional book for learning how to do squats.
There are always going to be differences in form between different coaches. Therefore, unless one subscribes to the reasoning behind a particular approach, one cannot say that one form of squat is the best. However, we can point out the best instances of teaching what are generally regarded as safe and effective squat methods.
If looking at sources on the web and in print generally, here are some pitfalls to avoid: - If someone says to be careful of squats because they damage the knees, set off an alarm bell in your mind. - If someone says not to squat too deep--for instance, only above parallel, or to a 90 degree angle between the femur and tibia--jam your ears and back away slowly.
Some coaches who have particularly effective squat advice include:
- Mark Rippetoe, whose Starting Strength (second or third editions) is a staple for novices looking to learn the squat (and other lifts) for general strength purposes. He teaches a low-bar squat, which many consider to be a little powerlifting-specific.
- Greg Everett, whose Olympic Weightlifting book includes excellent discussion and instruction on the squat, as well as the more technical clean, jerk, and snatch. He teaches a high-bar squat that is excellent for general strength purposes.
- Matt Wenning, who teaches a powerlifting-specific approach to the squat in the So You Think You Can Squat series.
Personally, I would recommend picking up either Everett or Rippetoe's book, getting started, and dealing with any issues that arise. Both give solid instruction, though they disagree on some points. (You can always switch from low-bar (Rip's method) to high-bar (Everett's method) after trying it for a while.) If you feel like switching to a more powerlifting-centric approach, Wenning would be appropriate.
(If you're particularly unathletic, Dan John's goblet squat is a dirt-simple alternative to the back squat. If you feel intimidated by the bar, find it too heavy to start, or want to be super-safe, and you aren't concerned with how fast you gain strength, stick with the hard-to-mess-up goblet squat.)