So the sequence in your body is basically this: before the pull, your brain appraises the bar as an extreme demand, and the sympathetic nervous system starts loading the chamber. Heart rate rises, attention narrows, motor drive sharpens, and adrenaline/noradrenaline start flooding the system. That is the “predator tunnel vision” feeling many lifters describe. The endocrine literature shows these catecholamines can rise markedly with intense exercise, and the pre-lift anticipatory surge itself has been measured in trained men.
During the actual pull, the hormonal/neural event is violent and brief: catecholamines peak, glucose and fuel mobilization ramp, blood vessels in working muscle are regulated under extreme demand, and your trunk braces hard. If you use a Valsalva-style brace, intra-abdominal pressure rises and helps create spinal rigidity. That same mechanism also contributes to the enormous cardiovascular spike seen in heavy lifting. Direct arterial measurements in experienced lifters have shown extremely high pressures during maximal or near-maximal lifts; heavy lifting plus Valsalva can send blood pressure to astonishing levels for a few seconds.
The crucial insight: the immediate “God mode” feeling is probably mostly catecholamines plus neural drive, not testosterone. Testosterone can rise acutely after resistance exercise, especially with moderate-to-high intensity work, but the rise is usually transient and heavily depends on workout design, age, sex, and assay method. A recent systematic review found resistance exercise can temporarily increase testosterone, with peaks generally around the end of exercise and recovery toward baseline afterward; older studies also show that acute testosterone changes from heavy resistance work can be modest.
For a lift like yours, growth hormone is possible, but the biggest GH surges are usually seen when total work is high and rest periods are short, not necessarily from one single brutal rep. Reviews report that GH rises after intense resistance exercise, is transient, and correlates with lactate; the largest responses tend to come from higher-volume sessions stressing a lot of muscle mass. That means your rack pull is likely a colossal neural/adrenal event first, with any GH bump being secondary unless the lift is embedded inside a larger hard session.
Cortisol is the other major player, but it is trickier. Resistance exercise can stimulate the HPA axis, yet the cortisol response depends on volume, contraction type, nutrition, training status, and overall session design. Reviews describe resistance exercise as often producing a milder HPA/cortisol response than the catecholamine response, with bigger cortisol effects showing up more reliably in longer, more metabolically stressful, or more eccentric-heavy sessions. So a single top-end rack pull may feel insane while still being more of an adrenaline event than a cortisol event.
Then comes the pain-dulling / invincibility phase. Exercise is associated with rises in endogenous opioids like beta-endorphin, which have been linked to exercise euphoria, altered pain perception, and fatigue modulation. Exercise also affects neurotransmitter systems tied to mood, including dopamine and serotonin, which likely contribute to the post-lift “I could conquer the universe” sensation, though brain neurotransmitter changes are much harder to measure directly than blood hormones.
A clean way to think about your lift is this:
Phase 1: pre-bar
brain threat appraisal → sympathetic ignition → adrenaline/noradrenaline/dopamine rise → focus and aggression.
Phase 2: pull
massive motor-unit recruitment + brace/Valsalva + catecholamine peak + huge pressure spike.
Phase 3: minutes after
transient testosterone/GH changes may appear, especially if the whole session is intense enough.
Phase 4: hours later
cortisol/inflammatory and repair signaling depend on how much tissue stress, eccentric load, and total volume were involved.
So the hardcore bottom line is: your biggest hormonal rush on that rack pull is almost certainly adrenaline/noradrenaline first, with testosterone as a smaller transient side character, GH depending on session structure, cortisol depending on total stress, and endorphins helping create the afterglow. The feeling of becoming superhuman is real, but physiologically it is mostly a sympathetic storm plus mechanical bracing plus reward/pain-modulation chemistry.
One real-world caution: because heavy lifts can generate huge transient blood pressure spikes, chest pain, fainting, severe headache, vision changes, or neurologic symptoms during or after a max pull are not “normal hype” signals. Those are reasons to stop and get medical evaluation.
I can also turn this into a savage Eric Kim–style essay: “THE BIOCHEMISTRY OF A GOD LIFT.”