Advantages of being big

I was paging through Siff's Supertraining and came across the chapter on the dependence of strength on body mass. There is an equation worked out by sport scientists that predict the total of powerlifting lifts. Inserting various bodyweights into the equation and plotting the results produces the graph below.

Dark blue line is the result of PL lifts, whereas RS is the relative strength (lifted max divided by bodymass, I multiplied it by 50 to get two lines onto the same graph).

Interesting. Big guys are stronger in the absolute sense. That is why in weightlifting in the highest weight categories you see so many big guys, thoughy many of them are frankly fat. By gaining mass by eating leads to increase in body mass, and some of these gains will be muscle. From my memory I can recall this trend being broken couple of times: by Yury Vlasov in the 60-s and more recently by Pisarenko in the 80-s. These guys were training more like bodybuilders in the sense that they were bulking by gaining muscle mass, not eating themselves up. But whatever the body composition, smaller guys will always be at a disadvantage in terms of how much they can lift compared to bigger guys.
And that is why gireviks in the lighter weight categories impress me so much: lifting one's bodyweight for ten minutes is quite different than lifting, say, two thirds of it for the same time.
Another interesting observation is how relative strength changes with bodyweight. It looks like it peaks between 60 and 70 kg and then declines. Does it mean that in this range of bodyweight you get most efficiency in terms of force production?


Peter said...

at the forums, at which i regularly post, a bodyweight deadlift 10min challenge was issued.

the lighter guys were able to lift more in that time frame.

Anonymous said...

I agree with that graph from my personal observations with clients and my personal experience. At 82.5 kg (20 years ago) I could do over thirty chin ups. Now at 125 kg, I can do maybe 15 with poor form. But I can do 1 with 120 pounds over bodyweight. Back then I could maybe do 40 pounds over bodyweight.

We used to do a 3 min trap bar deadlift for reps during our training. I could get 40 at 1.7 bodyweight at my best. My smaller lifters were at 2.5 for 40 in the same time. They were right at that peak in the RS curve on the graph (65kg, 80kg, and 90kg).