Fight Gravity Vertically
When Sir Isaac Newton discovered the theory of gravity over 300 years ago, I'm guessing he gave little thought to its impact on lifting. But if Newton were to walk up to a loaded barbell, and lift said barbell, he would immediately realize its significance. (I'm guessing he'd know how to handle business, though.)
Gravity is a force we can always count on being around, and that force always acts vertically. Never will it slide to the right a little, or drift to the left some. It ALWAYS acts straight up and down. As a result, when lifting a barbell, we want to move it on the path of least resistance. What is that path you might ask? You guessed it, vertically! We want to move the bar straight up, and then straight back down. Any horizontal motion when lifting the barbell will result in wasted movement, as well as inefficient energy expenditure; this happens because the weight veers from our center of mass, or the optimal balance point by which we execute the barbell lift.
To illustrate this, take a look at the picture we pulled from Starting Strength Basic Barbell Training, third Edition, by Mark Rippetoe. From the picture, you can see that even a slight deviation can significantly impact a weight. (Granted, the picture doesn't show a weight being lifted, but hopefully you get the point. As a weight moves off balance horizontally, it become much more difficult to manage.)
So the next time you attempt to pull a heavy deadlift or squat a new PR, just remember what Sir Isaac would do. He would fight the vertical force of gravity by gritting his teeth and moving that bar straight up!
(What's the best way to biomechanically do this? Stay tuned to future posts...)