Ben Greenfield: The #1 Biohack Is Free (And It's Not Diet or Exercise)

Greenfield defines moderate intensity as the range between ventilatory threshold 1 (where conversation becomes difficult) and VT2 (where lactic acid accumulates faster than it can be cleared). Vigorous intensity is above VT2, which feels like a hard burn. He stresses that most people never come close to the harmful thresholds, but the fitness junkie crowd easily exceeds them. He believes biohacking tools like hyperbaric oxygen and PMF might allow some to go beyond safely, but he personally stays well within the Goldilocks zone and now only walks, plays sports, and does super-slow lifting.

Greenfield refers to Doug McGuff's book 'Body by Science' for the concept. He uses a Tonal machine set to 'burnout' and 'eccentric' modes, so the machine resists on both the concentric and eccentric portions, making the muscle work maximally for the entire 2 minutes. When traveling, he approximates this with Nautilus machines, free weights, or blood flow restriction bands to simulate heavy load with lighter weights. He also mentions ARX, a two-horsepower motorized machine that pushes and pulls you through the range of motion. The sucky part is the extreme discomfort, but the total time commitment is very low.

Greenfield always travels with these three items weighing about two pounds total. He uses them in hotel rooms or parks to replicate his at-home super slow training effect. He previously used heavy gym equipment but now relies on this system to stay consistent.

Greenfield compares the shaking effect to how prey animals shake after a chase to discharge stress. At home, he wired the Roxiva lamp's audio output into the Shift Wave chair so the light show drives the vibration pattern, creating a fully synchronized experience. For travel, the Apollo wristband and NeuroVizor headset provide a lighter version. He books this relaxation block as non-negotiable, even though he only sleeps about 6 hours per night, because it allows him to be 'super present' with his family for the evening dinner party.

This is the second bookend of Greenfield's day. He says he deliberately ends work by 7 p.m. to join the family for this 'amazing party.' The routine includes a song, a book chapter discussion, then dinner and games. This structure allowed him to stop being a workaholic and be fully present. He ties this back to the research on belonging and the five regrets of the dying, one of which is 'I wish I'd stayed in touch with my friends.' He views this family time as a critical longevity practice.

Greenfield views the body as an electrical system and notes we live in a 'man-made electrical soup' that can disrupt cellular charge. He has grounded floors throughout his house and wears grounding shoes outdoors. PEMF is a concentrated version of earthing. When injured, he often googles 'PMF + city name' to find a mat to use. He describes wrapping a coil around his knee or laying on a mat for back cramps and feeling immediate relief.

Greenfield's new house is meticulously designed with every floor layer containing a copper conductive grid that routes to a ground rod. He says being on the third floor feels the same as being barefoot on the earth. He also wears grounding shoes to maintain conductivity when outside. This is part of his broader environmental approach: no Wi-Fi, only shielded Ethernet, flicker-free full-spectrum lighting, incandescent+OLED for circadian, and low-EMF design.

Greenfield explains that hypoxia creates a hormetic stress that triggers autophagy of dysfunctional mitochondria, and then flooding with oxygen afterward stimulates new mitochondrial production. He also does this in a hyperbaric chamber, which adds pressure to drive oxygen deeper. He notes that just breathing 93% oxygen at the start of a workout can make you feel 'unstoppable.' This is part of his daily oxygen toolkit along with hyperbaric sessions for stem cell activation and telomere lengthening.

Greenfield points to the US Surgeon General's 2023 statement equating loneliness to 15 cigarettes a day. He describes 'social genomics' where conflict with others upregulates inflammatory genes and love/connection upregulates repair genes. The paradox of loneliness is that the loneliness-driven hypervigilance, anxiety, and irritability make someone even less approachable, creating a vicious cycle. In-person touch (handshakes, hugs) stimulates Pacinian corpuscles to activate the vagus nerve, releasing oxytocin and serotonin, whereas digital interaction misses this layer entirely because it lacks the physiological sensory input. To combat this, he and his family built a family mission statement, logo, crest, and they gather every morning at 7 a.m. for prayer and sharing, and every evening at 7 p.m. for a song, book chapter, and board games. He says this book-ending protects him from workaholism and gives his sons a deep sense of belonging.