High-intensity interval training
Short all-out efforts with full recovery in between, a few times a week
Repeated bursts of maximal effort, from twenty seconds to a few minutes, separated by enough rest for heart rate to come most of the way back down. Sprints, bike intervals and circuit machines all work. The appeal is time: a session can be under twenty minutes, and studies show gains in mitochondrial function and aerobic capacity comparable to far longer steady cardio. It is hard by design and easy to overdo, so most people cap it at two to four sessions a week and keep the other days easy.
People on record
Sorted by strength of stance
Does it: documented as part of their own routine. Recommends: explicitly advises other people to do it. Discusses: covered it substantively without clear personal adoption; this can include criticism or disagreement.
- Cristiano RonaldoDoes it
Footballer · Portugal captain and five-time Ballon d'Or winner
Says his team does a lot of sprinting drills in training and suggests adding them to every workout, in the gym or outdoors. Goal frames the on-pitch work as high-intensity drills that mirror match situations, with the gym split between weights and cardio.
Source: Goal: What are Cristiano Ronaldo's diet, workout and fitness secrets? - Dave AspreyDoes it
Biohacker · Bulletproof Coffee
About 20 minutes a week, split into three or four all-out sessions with full recovery between efforts, using AI-driven machines and blood-flow-restriction bands at his Upgrade Labs gyms. He traces the approach back to 18 months of 90-minute workouts six days a week in his twenties that still left him with a 46-inch waist.
Source: Dave Asprey blog: How I Workout Only 20 Minutes A Week“I break my workouts into three or four short sessions each week. Each one focuses on all-out effort followed by full recovery.”
Dave Asprey blog: How I Workout Only 20 Minutes A Week (opens in a new tab) · 11 Jun 2025 - LeBron JamesDoes it
Basketball player · NBA all-time leading scorer
Summer conditioning means 100-yard sprints end zone to end zone on a football field, partly because it puts him outdoors and takes him back to high school football. There is no set count; they run until the heart rate is where they want it and Mancias calls a stop.
Source: The Tim Ferriss Show #349 transcript: LeBron James and Mike Mancias - Mark HymanDoes it
Physician · The Dr. Hyman Show · author of Young Forever
Four to six days a week of aerobic work, about half an hour of intervals, on a road or mountain bike and indoors in winter. Tennis, hiking and swimming fill in the rest.
Source: The Doctor's Farmacy: My Personal Longevity Routine - Stacy SimsDoes it
Exercise physiologist · Women Are Not Small Men
Short intervals are what she reaches for when her body clock is wrecked after a long-haul flight. She admits it is the last thing anyone jet lagged wants to do, then calls it one of the better resets available, and says she keeps her own session brief and outdoors.
Source: Dr Stacy Sims: Why Jet Lag Hits Women Harder - Pavel TsatsoulineDiscusses
Strength coach · StrongFirst
Conditioning by burn gets pushed back on: hard-living types wreck themselves in the glycolytic pathway, he writes, and there are other ways. His alternative is a kettlebell circuit of clean, press and squat, one side then the other, at a pace holdable for twenty or thirty minutes, credited to a StrongFirst team leader.
Source: StrongFirst: Strength Aerobics, A Powerful Alternative to HIIT
Aimed at the same thing
Other entries filed under fitness, energy or longevity.
- Protocol$$$Cheap: Roughly under $50, or under $15/month.
Resistance training
Lifting weights 2-4 times a week to build and hold muscle
On record from 43 of 62 tracked people: 37 do it, 4 recommend it, 2 have discussed it - ProtocolFREE, no cost
Zone 2 cardio
Easy aerobic work you can hold a conversation through, 3+ hours a week
On record from 12 of 62 tracked people: 5 do it, 5 recommend it, 2 have discussed it - Protocol$$$Cheap: Roughly under $50, or under $15/month.
Cycling
Steady riding, outdoors or on a stationary bike, as daily low-intensity cardio
On record from 9 of 62 tracked people: 9 do it - ProtocolFREE, no cost
Daily cardio
Around half an hour of aerobic work most days, at any pace you can sustain
On record from 4 of 62 tracked people: 4 do it - ProtocolFREE, no cost
Polarized training
Most sessions easy, a few genuinely hard, almost nothing in the middle
On record from 1 of 62 tracked people: 1 recommends it - Protocol$$$Cheap: Roughly under $50, or under $15/month.
Protein-forward eating
Roughly 1g of protein per pound of target bodyweight, spread across meals
On record from 21 of 62 tracked people: 15 do it, 5 recommend it, 1 has discussed it
Protocol entry · notes paraphrased from cited sources, quoted excerpts copied from the transcript they link to. Not medical advice. Not affiliated with, endorsed by, or reviewed by anyone listed. How this works.