How Weight Loss/Gain Affects Leverages and Biomechanics
Many times people confuse weight loss and gain’s affect on strength to be solely from muscle differences, but that fact is many of the short term changes you will see stem from changes in leverages and biomechanics. Here (click to see video) we have a side by side video of Nick hitting 450lbs. just two weeks apart, with the video on the right actually being the 2nd rep of his 450×2 set. Nik has just recently dropped from 227lbs. bodyweight to now being 205lbs. as of yesterday morning. The difference in speed you are seeing between those squats is the adjustments to leverages that had to be made due to his weight loss. If you scroll to the second video, you will see the difference in Nik’s squat from his highest bodyweight on the right versus now on the left. Notate that with the same mental cues and form, the end range of hip flexion occurs much sooner when he was at 227lbs. So what correlated with his weight loss was increased degrees of hip flexion range of motion, which eventually resulted in increased depth that actually was detrimental to his strength.
The results of weight loss or gain greatly affects a persons leverages and biomechanics on all 3 lifts. Bench press many times is the most affected, and that stems from a now increased or decreased range of motion due to the thickness of your chest and back. If you lost 20lbs. and went down 3 inches on your chest measurement, there will now be an increased range of motion that bar must travel through. On squats as shown above, the main factor that is affected is the range of motion for hip flexion, possibly now changing the mechanics of your lift from having more or less hip flexion. And the same goes for deadlift in how hip flexion range of motion is affected, but weight gain can at times end up being a detriment in this aspect versus a benefactor. Greg Nuckols did a great overview of this (Click Here For Article), but the heavier weight classes (275+) at times have worse deadlifts, or at least comparatively, than the 220-242 range (such as Yuri Belkin and Cailer Woolam). This seems to be due to the inability to achieve proper positioning due to limited hip flexion range of motion. So what are some simple tricks?
1.) For bench press, there is a reason you tend to seeing lighter weight class lifters arching more with a wider grip while heavyweights are arching less with close grips. It is the biomechnical way to improve leverages if you have a lower bodyweight. Versus heavier lifters can work more on brute strength as their range of motion naturally is less. So based on your weight gain or loss, you may find new grip positions and/or back positions start to become more advantageous/disadvantageous due to your new leverages.
2.) For squat, you will notice lighter weight classes tend to have narrower stances while heavier weight classes have wider stance widths. This is occurs fairly naturally to allow for those lifters to achieve adequate hip flexion, but not an excessive amount. Try it yourself. Try squatting with a closer stance and see how deep you can get before your torso hits your thighs (once hip flexion ends, you must either then find range of motion from the knees or the back, aka butt wink), and then widen out and try the same thing. Hip anatomy can definitely play into this, but most likely you will notice a slightly better ability to achieve higher degrees of hip flexion with a slightly wider stance. But this doesn’t mean you have to change your stance. Notate with Nik that we did not adjust his stance at all with his weight loss, we simply cued for him to cut his squat higher. He no longer needed to go to his end range of hip flexion, but rather could instead stop a bit short.
3.) For deadlift, most people will not need to adjust much with weight gain or loss, but if you do get to the point where hip flexion range of motion is a detriment to your ability to achieve proper position off the floor, a slightly wider stance could be beneficial. Notate the heavyweights who have big deadlifts such as Ray Williams, Brian Shaw, and Eddie Hall. You will notice they take a fairly wide stance, which allows them to achieve that improved positioning.