Notes on Dr. Stacy Sims' Book: Next Level

My wife recommended this book, and a few clients had brought it up as well. Some of what I found inside was different than I expected, so I decided to dig in.

After studying Next Level carefully, it became clear how strongly the physiology of menopause aligns with the type of training we emphasize — but there are also very specific considerations about hormonal changes that deserve real attention.

One of the biggest takeaways is that much of the exercise science we rely on has historically been based on research in men. Women — especially peri- and post-menopausal women — have distinct needs that change how they should train, eat, and recover. These notes summarize the key points for anyone who might find them useful.

Note: Dr. Stacy Sims has faced scrutiny from researchers regarding her claims on training fed vs. fasted, meal timing, and lifting heavy vs. moderately heavy. Long-term randomized control trials don't appear to exist in these categories. In my perspective, Stacy is pushing the conversation and driving debate — it's a genuinely new area of research that I think is greatly needed.

Hormones & Definitions

Anabolic: building tissue (muscle, bone, organs)
Catabolic: breaking down tissue
Sympathetic nervous system: fight or flight, high stress
Parasympathetic nervous system: rest and digest, recovery

Estrogens

E1 – Estrone

Weaker estrogen; becomes the dominant form after menopause because it is produced in fat tissue.

E2 – Estradiol

The strongest and most biologically active estrogen. It:

Is anabolic (supports muscle & bone)
Increases insulin sensitivity
Helps regulate appetite
Directly supports muscle contractile proteins (myosin)
Supports mitochondrial function (aerobic metabolism)
Enhances serotonin (mood)
Helps regulate body temperature & vasodilation
Supports bone formation
Increases joint laxity (looser connective tissues)

E3 – Estriol

Mainly present during pregnancy.

Progesterone

More catabolic
Counterbalances estrogen
Raises core body temperature
Can reduce neuromuscular coordination and increase fatigue
Has anti-anxiety effects and increases BDNF
Increases pain tolerance
Suppresses immune response (to protect a potential embryo)

Cycle context (premenopause): Estradiol (E2) peaks around week 2. Progesterone peaks around weeks 3–4.

The Menopausal Cascade

When E2 and progesterone decline:

Effects of Low Estradiol (E2)

Less anabolic → less muscle & bone, slower recovery
Lower insulin sensitivity → easier fat gain
Increased appetite
Lower mood (less serotonin)
More fatigue
Higher blood pressure
Higher cardiometabolic disease risk
Less stable thermoregulation (hot flashes, night sweats)
More joint discomfort due to changes in collagen structure

Effects of Relative Estrone (E1) Dominance

Since total estrogen drops, E1 becomes the primary form. It is produced in fat tissue, often driving:

Increased abdominal fat
Higher cortisol
More fat storage and worse sleep

Combined Low E2 + Low Progesterone

Increased systemic inflammation
Gut disruption
Higher hepcidin → greater risk of anemia
~25% lower pain tolerance
Lower HRV and impaired recovery
Temperature instability

Progesterone loss specifically causes: mood swings, memory issues and brain fog, lower pain tolerance, bone loss, and worsened sleep due to loss of temperature regulation.

Gut Health

Why gut health matters: mental health, body composition, bone density, nutrient absorption, sleep, antioxidant production, mitochondrial function, inflammation control, ATP production, lactate clearance.

Firmicutes vs. Bacteroidetes

Firmicutes: more efficient calorie extraction; often higher in obesity
Bacteroidetes: often higher in lean people

A higher Firmicutes:Bacteroidetes ratio is associated with obesity, but not deterministic — it affects calorie extraction efficiency and inflammation without overriding energy balance entirely.

How to improve the ratio

Eat fiber-rich fruits & vegetables; target 25 g fiber/day
Legumes, nuts, seeds
Coffee
Fermented foods (probiotics)
Prebiotics: garlic, onions, leeks, asparagus

A healthier microbiome helps metabolize estrogen more effectively, easing symptoms. Bottom line: healthy food → healthier gut → better menopause outcomes.

Training Guidelines

Note on fasted training: Dr. Sims advises against training fasted. However, longitudinal studies don't clearly support this, and the claim is hotly contested. It is better to exercise than not to — I would not let meal timing get in the way.

The reasoning is that women in peri/menopause respond poorly to fasted training due to higher cortisol, lower blood glucose stability, more muscle breakdown, and worse adaptations. The recommendation is to eat protein + carbs before and after training.

The Core Idea: Replace What Estradiol Used to Do

Lift heavy. Muscle is metabolic currency. Menopause accelerates the loss of both muscle and bone — bone density can decline by up to 20% during the transition.

Light weights for high reps do not produce a strong anabolic signal. Long, steady cardio combined with low calories increases cortisol and often leads to muscle loss, fat gain, and worsening symptoms.

Note: The key is training close to failure. Lighter weights are inefficient.

Strength training appears to be far more effective than endurance training for improving body composition and health outcomes in menopausal women — there is good long-term study data here. It also improves immune function → fewer sick days.

Energy Intake: Why You Must Eat Enough

Under-eating in menopause causes higher cortisol, thyroid downregulation, lower metabolic rate, muscle and bone breakdown, and increased fat storage as the body goes into "protective mode."

To lose fat:

Maintain adequate fueling around workouts
Maintain sufficient total calories
Use brief, intense training to create a metabolic shift
Avoid chronic, large deficits

Note: Stacy says women need to refuel within ~30 minutes post-exercise; men have a longer window (~90 minutes). This has generated significant debate and long-term studies are hard to find.

The key goal: maximize lean mass to drive metabolic rate, energy, strength, and symptom control.

Macronutrient Example (Active 130 lb / ~59 kg Woman)

Macro	Per kg	Total	Calories
Carbs	3 g/kg	177 g	708 kcal
Protein	2.2 g/kg	130 g	520 kcal
Fat	1.2 g/kg	71 g	639 kcal
Total			~1,867 kcal

This feels high only because many women are taught to eat ~1,200 kcal — which is drastically under-fueling and metabolically harmful.

What EverStrongSF Already Does

Lift heavy → strong anabolic signal, lowers cortisol, builds muscle, improves mood & sleep
Low volume + high intensity → reduces catabolic load
Eat protein + carbs pre- and post-training (significant debate exists here)
Build core strength → helps with pelvic floor issues

Why Brief High-Intensity Strength & Sprint Interval Training Work Best

With low estrogen, you burn less fat at rest, store more abdominal fat, and have blunted anabolic signaling. Strength training combined with sprint interval training (CAROL bike, etc.) acts as medicine:

Burns circulating glucose (E2 normally helps do this)
Provides a strong anabolic stimulus
Improves insulin sensitivity
Reduces visceral fat
Increases VO₂ max
Improves cardiac stroke volume and lowers resting heart rate
Improves thermoregulation (vasodilation)
Improves blood pressure control
Reduces cortisol over time
Supports bone density and connective tissue remodeling

Long, steady endurance cardio absolutely improves cardiovascular health. However, when menopausal women rely mostly on long cardio — especially while under-eating — it can drive up stress hormones, contribute to muscle loss, and be less effective for body composition than a combination of heavy strength training, sprint intervals, and proper fueling.

Supplements

These are what the book discusses. Always consult your physician before starting any supplement.

Beta-alanine — Helps with high-intensity efforts (buffering). May help women tolerate hard intervals better. Not a direct "hot flash cure," but can reduce exercise discomfort.

Ashwagandha — 250 mg can reduce stress/cortisol. Avoid with thyroid issues or hormone-sensitive prostate cancer.

Holy Basil — 500 mg twice daily for stress reduction.

Rhodiola — 150 mg. Helps with cognition & fatigue. Avoid with MAOIs, low blood pressure, or late in the day. Avoid if you have estrogen-driven cancers.

Schisandra — Stimulant/adaptogen. Avoid late in the day. Check your dose carefully — the dosage cited in the book appears to contain a misprint.

Maca — Performance/mood stimulant at 2.5–3 g. Not known to be WADA banned (a common misconception), but all supplements carry contamination risk. Avoid with thyroid issues.

Interesting Research Note

Women with high muscle mass and high fat mass had a ~42% lower risk of heart-disease–related death compared to women with low muscle and low fat.

In other words: muscle matters more than leanness.