Compare experts › Peter Attia vs Stacy Sims

Peter Attia vs Stacy Sims

Q: How much protein do Attia and Sims recommend?

Attia: 1.6–2.2 g/kg. Sims: ~1 g per lb (≈2.2 g/kg).

Peter Attia (physician) and Stacy Sims (exercise physiologist) 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.

Build a plan from both See the protocols

Words explained (15)

Zone 2: Steady cardio at a pace where you can still talk in full sentences, but not sing.
VO2 max: The most oxygen your body can use in hard exercise. A good measure of fitness; higher is better.
Intervals: Short hard efforts with easy recovery in between, such as 30 seconds fast, 90 seconds slow.
4 × 4: Four rounds of 4 minutes hard with 3 minutes easy in between. Also called Norwegian intervals.
Hinge: A movement that bends at the hips with a straight back, like a deadlift or picking a box up from the floor.
Mobility: Moving your joints freely through their full range.
Creatine: A well-studied supplement that supports strength and muscle.
Omega-3 (EPA, DHA): Healthy fats found mostly in oily fish such as salmon, herring and sardines.
Time-restricted eating: Eating all your meals within a set window of the day, for example 8am to 6pm.
ApoB: A blood test that counts the particles carrying cholesterol. Linked to heart disease risk.
Perimenopause: The years of changing hormones before periods stop for good.
Hormone therapy (HRT, MHT): Medicine that replaces hormones that fall at menopause. Only a doctor can prescribe it.
Rapamycin, metformin: Prescription drugs that some experts take hoping to slow ageing. Not proven for that, and never part of your plan.
Medicine 3.0: Peter Attia's name for preventing disease early instead of treating it late.
Centenarian: Someone aged 100 or older.

At a glance

Measure	Peter Attia	Stacy Sims
Background	Physician	Exercise physiologist
Training split	40% strength · 40% aerobic · 10% intervals · 10% mobility	60% strength · 10% aerobic · 25% intervals · 5% mobility
Signature habit	Zone 2 + VO2 max	Heavy lifts + sprints
Protein	1.6–2.2 g/kg	~2.2 g/kg
Training style	Balanced	Women 40+
Overall evidence	Strong	Strong
Following	Instagram 1.6M · YouTube 1M	Instagram 1.4M · YouTube 372K

Training splits are our estimates from each expert’s published routine. Following checked October 2026.

The key differences

Sims puts more of the week into strength: about 60% against 40%.
Attia puts more of the week into aerobic base (zone 2): about 40% against 10%.
Sims puts more of the week into intervals: about 25% against 10%.
In plans in their style, Attia's hard sessions are 4-minute intervals (Norwegian 4 × 4); Sims' are short sprints.
We rate the overall evidence behind both protocols as strong.
Supplements that go into a plan: Attia, omega-3; Sims, creatine monohydrate. Prescription items and personal stacks stay out of every plan.
Only Attia 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

Peter Attia

Zone 2 cardio (a steady pace where you can still talk) about 3 hours a week, for example 4 × 45 min. Start with about 2 hours if new to itStrong evidence
VO2 max intervals: 4 min hard, 4 min easy, repeated 4–6 times, once or twice a weekSome evidence
Heavy strength training 3–5 times a week, focusing on grip, slow lowering, pulling and hip-hinge movementsStrong evidence
Stability and balance work woven into most daysSome evidence
Benchmarks such as carrying half your body weight in each hand for 1 minute (men; about 75% of that for women) and long dead hangsPersonal habit
Choose the physical tasks you want to manage at 100 and train toward them nowNote

Stacy Sims

Strength training 3–4 times a week, 45–60 minutes, built on compound liftsStrong evidence
From perimenopause, lift heavy: about 3–5 sets of 6 reps or fewer, leaving 2–3 reps in reserve, with 2+ minutes restSome evidence
Sprint intervals of 30 seconds or less, all-out, with full recovery; 1–2 sessions a weekSome evidence
Jump and impact work (e.g. squat jumps, box jumps) for bone; one studied protocol is 10–20 jumps twice a daySome evidence
Keep easy cardio (walking, easy rides) as recovery; she plays down long moderate-intensity sessions and zone 2 for midlife body-composition goalsPersonal habit
'Ten-minute rule': if you still feel flat after a 10-minute warm-up, scale the session downPersonal habit

Eating

Peter Attia

Protein at least 1.6 g per kg of body weight a day. About 2.2 g/kg is the better target for active people with healthy kidneysSome evidence
Spread protein across about four meals of roughly 40–50 gPersonal habit
Follows no named diet. Focuses on energy balance and avoiding junk foodNote
Doubts time-restricted eating as a general tool and saves longer fasts for specific patientsNote
Says alcohol has no biochemical benefit. Personally keeps it to 0–8 drinks a week, at most 2 a dayPersonal habit

Stacy Sims

Do not train fasted: about 15 g protein before lifting, plus about 30 g carbohydrate before cardio of up to an hourSome evidence
After training: 40–60 g protein (perimenopause on) within about 45 minutes, and carbohydrate within 2 hoursSome evidence
Daily protein around 2.2 g/kg body weight, the top of the 1.4–2.2 g/kg range in her ISSN position standSome evidence
Protein at meals 30–40 g, snacks 15–20 gSome evidence
Avoid long fasts, keto and big calorie cuts if active; a small deficit (about 150–200 kcal) in the evening, away from training, if aiming to lose fatPersonal habit

Supplements

Peter Attia

Fish oil reported at about 2 g EPA + 1.5 g DHA a day, aiming for a blood omega-3 level of about 8–12%Some evidence
Vitamin D, reported at about 5,000 IU a dayPersonal habit
Magnesium from several forms, about 1 g elemental a day in total (reported)Personal habit
Methylfolate and vitamin B12 to keep homocysteine below about 9 µmol/L, based on blood testsDoctor only
Prescription drugs such as statins or PCSK9 inhibitors to lower apoB when neededDoctor only
Treats rapamycin and metformin as unproven, experimental options, not general adviceNote

Stacy Sims

Creatine monohydrate 3–5 g a day (start with 1–2 g if unsure), paired with strength trainingStrong evidence
Choose third-party tested products (NSF or Informed Sport)Note
Vitamin D3, omega-3, collagen and turmeric mentioned as options; no doses givenPersonal habit
Iron only if a blood test shows low ferritinDoctor only

Sleep & recovery

Peter Attia

Allow 8–9 hours in bed with a fixed wake-up timeStrong evidence
Cool, dark bedroom, about 18 °CSome evidence
No food in the last three hours and no alcohol close to bedtimeSome evidence
Screens off well before bed. He keeps a second phone with no social appsPersonal habit
Sleep aids he has reported using: glycine, ashwagandha and magnesium L-threonate. Melatonin only for jet lagPersonal habit

Stacy Sims

Traditional (Finnish-style) sauna at about 60–80 °C after training; she prefers heat to cold for womenSome evidence
If using cold water, choose cool (about 16 °C) rather than ice-coldPersonal habit
Treat easy days as true recovery between hard sessionsPersonal habit
Sees hormone therapy as a valid option for hot flushes and bone risk, but not required for every womanDoctor only

Stress & mind

Peter Attia

Treats emotional health as a pillar as important as physical healthNote
Journaling as a regular practicePersonal habit
Keeps social media off his evening phone to protect wind-down timePersonal habit

Stacy Sims

Keep hard intervals short; she says longer efforts and very long sessions raise cortisol, already a concern in menopauseSome evidence
In perimenopause, have caffeine with food before training if it makes you shaky or light-headedPersonal habit
Listen to your own body and track responses rather than following a fixed planPersonal habit

Brain health

Peter Attia

Regular dry sauna (Outlive cites about 4 × 20 min a week at 80 °C or more, linked in Finnish studies to lower dementia risk)Some evidence
Sees ketogenic eating as a possible alternative brain fuel in early cognitive decline, based on small trialsSome evidence
Says the benefit of vitamin D for dementia risk is unclearNote

Stacy Sims

Creatine for brain fog and mood; she cites a trial where 5 g a day added to an antidepressant helped women with depressionSome evidence
Favours truly hard intervals over moderate or zone 2 cardio for midlife cognitive and metabolic benefitsSome evidence

Weak spots to know

Peter Attia

Many of his exercise targets lean on observational studies that link fitness or strength to longer life. These show association, not proof that hitting a given number will add years.
A 2026 review in the Australian Journal of General Practice called the book's research base superficial. It said his intensive, personalised approach suits only a few affluent people, and that routine full-body MRI scans use a lot of resources and bring risks from incidental findings that the book does not discuss.
Some critics argue that the medications and screening tests he recommends for healthy people lack strong trial evidence, and that the risks could outweigh the benefits.

Stacy Sims

Some researchers say her sex-specific advice goes beyond the evidence. A 2023 umbrella review co-authored by Stuart Phillips found no clear effect of menstrual-cycle phase on strength or training gains, and Sims publicly debated Lauren Colenso-Semple in 2025 on fasted training and protein timing, framed as mechanisms versus outcomes.
Her case against fasted training leans heavily on short-term hormone and appetite responses; critics note that longer studies measuring actual fat loss and muscle gain show little difference when daily calories are adequate.
Many of her menopause-specific prescriptions (exact sprint lengths, playing down zone 2, tight post-exercise protein windows) come from extrapolation and her own coaching experience rather than trials in midlife women.

Build a plan from Attia, Sims 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.

Plan in Attia's style Plan in Sims' style Mix both

Questions

What is the main difference between Peter Attia and Stacy Sims?

Their training split differs most in aerobic base (zone 2): Attia about 40%, Sims about 10% (our estimate from their published routines). Attia's signature habit is Zone 2 + VO2 max; Sims' is Heavy lifts + sprints.

How much protein do Attia and Sims recommend?

Attia: 1.6–2.2 g/kg. Sims: ~2.2 g/kg.

Whose advice has stronger evidence?

We rate the overall evidence behind both protocols as strong.

Do Attia and Sims disagree?

Not directly in what we reviewed. Their differences are in emphasis: sims puts more of the week into strength: about 60% against 40%.

Can I combine Attia and Sims?

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.

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Full sources are on each profile: Peter Attia · Stacy Sims. Reviewed October 2026.