Physics 101 meets hype 101 🚀
Force is measured in newtons (N); mechanical energy (work done) is measured in joules (J).
For a slow, single‑rep lift the average work you do is simply
\text{Work} = m \; g \; \Delta h
where
- m = mass on the bar,
- g ≈ 9.81 m s⁻²,
- \Delta h = how far the bar travels vertically.
Below is a side‑by‑side snapshot of Eric Kim’s 582 kg rack‑pull versus three other celebrated world‑class feats.
| Athlete | Lift (context) | Mass on bar (kg) | Approx. vertical travel Δh (m) | Force on the bar (kN) | Mechanical work* (kJ) | Work per kg body‑weight (J · kg⁻¹) |
| Eric Kim | Rack‑pull from knee pins | 582 | 0 .25 | 5 .71 | 1 .43 | 20 |
| Hafþór Björnsson | 501 kg full deadlift WR, 2020 (standard bar) | 501 | 0 .70 | 4 .91 | 3 .44 | 19 |
| Rauno Heinla | 580 kg silver‑dollar DL, 18″ height (2022) | 580 | 0 .45 | 5 .69 | 2 .56 | 18 |
| Lasha Talakhadze | 267 kg clean & jerk WR overhead (2021) | 267 | 2 .00 | 2 .62 | 5 .24 | 29 |
*Work values are averages for the concentric phase only (lowering phase is mostly dissipated as heat/sound). All distances are conservative mid‑range estimates used by strength scientists and coaches; slight variation doesn’t change the big picture.
What the numbers shout 🎙️
- Raw force champion.
Kim’s bar weighs in at 5.7 kN – the largest single static force of the group. Even Heinla’s record apparatus exerts ~5.7 kN, but Kim does it raw and at half the body‑mass of most strongmen. - Energy per kilo efficiency.
Because the rack‑pull travels only ~25 cm, Kim’s total mechanical energy (≈1.4 kJ) is modest. Where he annihilates expectations is energy per kilogram of lifter.
20 J · kg⁻¹ triples the “elite” 3 × BW deadlift standard for recreational strength athletes and edges Björnsson’s 501 kg full pull. - 8.2 × BW still matters.
Energy accounts for distance, but relative strength asks:
“How much iron can you move versus how much human you are?”
Kim’s 8.2 × dwarfs Björnsson’s ≈2.8 × and Heinla’s ≈4 ×. That ratio is why coaches, physicists, and meme‑lords lost their minds. It reveals a previously unseen density of strength – kilos moved per kilo of athlete – that rewrites human potential models. - ROM trade‑offs in plain sight.
Rack‑pulls let you hoist more weight by shortening the range of motion. The table quantifies that trade: Kim’s lift travels ~3× less than Björnsson’s, but the force spike is enormous. In coaching terms, the rack‑pull is the neural‑overload lab that teaches your body to feel supra‑maximal loads. - Why the hype is justified.
- Highest force on a straight bar ever handled at ~70 kg body‑weight.
- Relative work output on par with giants twice (or thrice) his mass.
- Proof that strategic overload + fearless mindset can beat the biological odds.
Take‑home power ⚡
- Force‑focused athletes (powerlifters, strongmen) can use partials to overload the lock‑out safely.
- Speed‑power athletes (weightlifters, jumpers) still need full‑ROM lifts for larger energy outputs, à la Lasha’s colossal 5 kJ jerk.
- Everyday lifters can borrow Kim’s lesson: progressive overload + specificity + belief scales mountains.
So when you next chalk up, remember: even 1.4 kJ can shake the world—if it’s 1.4 kJ delivered at 8× your own mass! Go chase your numbers and leave gravity filing complaints in your wake.