Rangan Chatterjee (doctor, former nhs gp) and Mike Israetel (sport physiologist (phd)) side by side: how they train, eat, supplement and sleep, how strong the evidence is, and how to build a plan from either or both.
Training splits are our estimates from each expert’s published routine. Following checked October 2026.
The key differences
Israetel puts more of the week into strength: about 65% against 30%.
Chatterjee puts more of the week into aerobic base (zone 2): about 50% against 25%.
Chatterjee puts more of the week into intervals: about 15% against 5%.
In plans in their style, both use 1-minute intervals for hard sessions.
We rate the overall evidence behind both protocols as solid.
Supplements that go into a plan: Chatterjee, none (food first); Israetel, none (food first). Prescription items and personal stacks stay out of every plan.
Only Chatterjee has a mobility or movement routine of their own.
Protocols side by side
Each line is rated for the evidence behind it. “Doctor only” items never go into a plan.
Training
Rangan Chatterjee
Walk at least 10,000 steps a daySome evidence
Strength training twice a weekStrong evidence
Short daily glute exercises (e.g. hip extensions), a couple of minutesPersonal habit
Five-minute home workout: five moves back to back, 20 s on / 40 s off for beginners or 40 s on / 20 s off for advanced, five roundsSome evidence
Swap any move that is too hard, painful or unsafeNote
Mike Israetel
For the average person, about 30 minutes of training twice a week gives the best return on time.Some evidence
After 40: most sets in the 10–20 rep range, some at 20–30, and 5–10 reps only rarely, because heavy low-rep sets raise the risk of injury.Some evidence
Train each muscle twice a week, starting with 1–2 hard sets per muscle per session, and add a set the next week if you recovered well.Some evidence
Lower the weight slowly and pause for 1–2 seconds at the bottom.Some evidence
Warm up more: three warm-up sets (light, medium, heavier) before the first working set, and 1–2 before each later exercise.Personal habit
Add weight in small steps: rarely more than about 2.5 kg or one rep per set at a time.Personal habit
Choose joint-friendly exercises with a high stimulus, for example a hack squat instead of a heavy back squat.Some evidence
Take a planned easy week every 4–6 weeks, and a lower-volume month about every 5 months.Personal habit
Eating
Rangan Chatterjee
Eat within a 12-hour window (for example 8am to 8pm), leaving about 12 hours a day without foodSome evidence
Five portions of different vegetables every dayStrong evidence
Around eight glasses of water a dayPersonal habit
Eat at least one meal a day at a table, with no phone or device nearbyPersonal habit
No fixed protein target in the sources we checkedNote
Mike Israetel
If you want to gain muscle, only gain weight when you are lean: about 0.25 kg a week for 4–8 weeks, then a fat-loss phase.Personal habit
Stay under about 20% body fat while gaining, come back to about 15% afterwards, and get blood tests after gaining phases.Personal habit
Sleep & recovery
Rangan Chatterjee
A tech-free wind-down before bed, ideally about 90 minutesSome evidence
Set a cut-off for work email in the evening (e.g. 8–8:30pm)Personal habit
Avoid emotionally charged topics, such as money worries, late in the eveningPersonal habit
Get daylight or time in nature in the morning, even five minutes, to help set the body clockSome evidence
Mike Israetel
No specific guidance in what we reviewed.
Stress & mind
Rangan Chatterjee
A daily stillness practice, starting with two minutes of meditationSome evidence
3-4-5 breathing: in for 3, hold for 4, out for 5, for about five minutesSome evidence
One full screen-free day a weekPersonal habit
Before bed, write down three things that went well and whySome evidence
Five minutes a day enjoying natureSome evidence
Mike Israetel
No specific guidance in what we reviewed.
Weak spots to know
Rangan Chatterjee
The 4 pillar approach is broad, sensible lifestyle advice, but the evidence behind specific claims is mixed; for example, a large trial found a daily eating window added no significant weight loss on top of cutting calories.
Some targets are round rules of thumb rather than research-based numbers: the 10,000-step goal is higher than where the benefit levels off for people over 60 (about 6,000–8,000), and eight glasses of water a day is a convention, not a tested target.
He has commercial ties alongside his health advice: books, an app and a paid community, and since 2023 an advisory role with Levels, a glucose-monitoring company.
Mike Israetel
Most of his content is aimed at bodybuilders and younger lifters; advice for people over 40 is a smaller part of it.
Many specific numbers, such as when to take easy weeks or how fast to add sets, are coaching rules of thumb rather than findings from trials.
He sells training programmes and diet products through RP, the company he co-founded.
Build a plan from Chatterjee, Israetel or both
Your free plan shows a week of gym sessions, cardio, a day of eating, supplements and mobility, fitted to your age, time and health.
What is the main difference between Rangan Chatterjee and Mike Israetel?
Their training split differs most in strength: Chatterjee about 30%, Israetel about 65% (our estimate from their published routines). Chatterjee's signature habit is Relax · eat · move · sleep; Israetel's is 2 × 30 min, close to failure.
How much protein do Chatterjee and Israetel recommend?
Chatterjee: No fixed target. Israetel: No fixed target.
Whose advice has stronger evidence?
We rate the overall evidence behind both protocols as solid.
Do Chatterjee and Israetel disagree?
Not directly in what we reviewed. Their differences are in emphasis: israetel puts more of the week into strength: about 65% against 30%.
Can I combine Chatterjee and Israetel?
Yes. In Build my mix you choose one expert per area, for example one for strength and another for eating. Your free plan shows the result straight away.