Mark Hyman (physician, functional medicine) 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%.
Hyman puts more of the week into intervals: about 30% against 5%.
Hyman puts more of the week into mobility and stability: about 15% against 5%.
In plans in their style, both use 1-minute intervals for hard sessions.
We rate the evidence behind Israetel's protocol higher: solid, against mixed for Hyman.
Supplements that go into a plan: Hyman, protein shake with creatine after training, omega-3 fish oil; Israetel, none (food first). Prescription items and personal stacks stay out of every plan.
Only Hyman 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
Mark Hyman
Strength training 3–4 times a week, about 30 minutes, mainly resistance bands and moderate weightsStrong evidence
Aerobic or interval training 4–6 days a week, about 30 minutes (cycling, tennis, hiking, swimming)Strong evidence
Yoga a couple of times a week plus a little stretching most daysSome evidence
Avoids very heavy lifting as he ages to limit injury riskPersonal habit
Hypoxia (low-oxygen) training with a machine or maskPersonal habit
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
Mark Hyman
Pegan diet: about 75% of the plate from plants, mostly non-starchy vegetablesStrong evidence
Cut sugar, refined flour and ultra-processed foodsStrong evidence
1–2 cups of cruciferous vegetables (broccoli, cabbage etc.) a daySome evidence
Healthy fats from olive oil, avocado, nuts, seeds and small oily fishStrong evidence
Avoid gluten and most dairy, even without intolerancePersonal habit
Daily overnight fast of 12–16 hoursSome evidence
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
Supplements
Mark Hyman
Protein shake after training: 30–50 g whey (goat) plus 5 g creatineStrong evidence
Vitamin D, fish oil, a multivitamin and magnesium at nightSome evidence
NMN (about 900 mg a day), urolithin A, quercetin, curcumin and similar 'longevity' compoundsPersonal habit
His own branded gut supplement (prebiotics, probiotics, polyphenols)Personal habit
Mike Israetel
No specific guidance in what we reviewed.
Sleep & recovery
Mark Hyman
7–8 hours of sleep with a regular bedtime around 10 pmStrong evidence
Dark, quiet bedroom with eye mask and earplugsSome evidence
Blue-light-blocking glasses in the eveningPersonal habit
Steam or sauna and cold plunge most daysPersonal habit
Red light therapy at homePersonal habit
Mike Israetel
No specific guidance in what we reviewed.
Stress & mind
Mark Hyman
Meditation once or twice a day plus breathworkSome evidence
As much time in nature as possibleSome evidence
Regular time with friends and familySome evidence
Regular massagePersonal habit
Mike Israetel
No specific guidance in what we reviewed.
Weak spots to know
Mark Hyman
Functional medicine as a field lacks randomised trial evidence; surgeon and blogger David Gorski (Science-Based Medicine, 2014; Respectful Insolence, 2019) argues its useful parts (diet, exercise, sleep) are not unique and its unique parts (broad testing, supplements, 'detox') are not proven.
A 2021 Red Pen Reviews analysis of Eat Fat, Get Thin scored its scientific accuracy 1.2 out of 4, finding the claim that saturated fat does not cause heart disease conflicts with most controlled studies.
Commercial ties are large: he co-founded and is chief medical officer of Function Health (direct-to-consumer lab testing) and sells supplements through his own online shop; nutrition scientist Adrian Chavez (Katie Couric Media, 2026) noted one of his supplement stacks supplies 7,000 IU of vitamin D a day, above the usual 4,000 IU upper limit.
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 Hyman, 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 Mark Hyman and Mike Israetel?
Their training split differs most in strength: Hyman about 30%, Israetel about 65% (our estimate from their published routines). Hyman's signature habit is Pegan diet; Israetel's is 2 × 30 min, close to failure.
How much protein do Hyman and Israetel recommend?
Hyman: 30–50 g shake after training. Israetel: No fixed target.
Whose advice has stronger evidence?
We rate the evidence behind Israetel's protocol higher: solid, against mixed for Hyman.
Do Hyman 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 Hyman 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.