Book summary “Roar”: summary

Introduction

Female physiology is fundamentally distinct from male biology, requiring targeted nutrition, recovery, and training strategies synchronized with hormonal phases rather than scaled-down male programs.

You likely follow fitness and nutrition advice built on studies of young male subjects. This generic guidance ignores your complex hormonal fluctuations across life stages. Stacy T. Sims demonstrates that you are not a small man. Your body possesses unique biological systems that respond poorly to standard caloric restriction and intermittent fasting.

The book maps out practical protocols across four core areas. You will learn how to adapt your training to distinct physiological traits and hormonal phases. You will discover how to navigate the transition through menopause and fuel your body correctly during pregnancy.

• How do your hormonal phases alter your daily nutritional needs?
• What specific training adjustments do you need during perimenopause?
• Why do standard sports nutrition products fail female physiology?

1. Battle of the Sexes

Female physiology possesses unique biological characteristics across muscle composition, cardiovascular output, thermoregulation, and biomechanics that demand specific athletic protocols.

Sports nutrition manufacturers often use a shrink it and pink it approach by offering smaller calorie counts and pretty packaging.

Female physiology requires specific treatment in training, fueling, and recovery because sex differences dictate how your body handles stress, energy, and environmental conditions. Stacy T. Sims suffered from severe hyponatremia and ended up in the medical tent at Ironman Kona while following standard male-centric nutrition protocols during the high-hormone phase of her menstrual cycle.

Physiological Differences

The menstrual cycle creates two distinct hormonal phases each month—high and low—that drastically alter metabolism, thermoregulation, and physical performance. During the low-hormone phase, you mirror men in carbohydrate metabolism and recovery. High estrogen causes your body to spare glycogen and burn more fat, while high progesterone delays your sweat response, raises core temperature, increases sodium loss, and accelerates muscle breakdown while hindering protein synthesis. Paula Radcliffe broke the marathon world record at the 2002 Chicago Marathon while experiencing menstrual cramps, and later criticized sports medics for giving runners synthetic progesterone to delay periods, which worsened performance.

Core needle samples show that men and women have similar muscle makeups, but you have a higher concentration of type I endurance fibers. Relative to lean body mass, trained women reach 70 percent of men's upper body strength and 80 percent of their lower body strength. Unadjusted measurements show women are 52 percent as strong as men in their upper bodies and 66 percent as strong as men in their lower bodies.

You have smaller organs and lower diastolic pressure, pumping out about 30 percent less cardiac output. This requires your respiratory muscles to work harder, diverting blood flow from your legs and lowering max VO2 by 15 to 25 percent on average. Men have 25 to 30 percent more lung capacity, 6 percent more red blood cells on average, and 10 to 15 percent more hemoglobin.

Women naturally carry higher essential and storage body fat, which provides a distinct metabolic advantage in long-distance endurance and open-water swimming. Essential body fat is about 4 percent in men and 12 percent in women due to reproductive design. Your healthy body fat range spans 12 to 30 percent, compared to 5 to 25 percent in men. Because fat is more buoyant and provides sustainable energy, female swimmers often outperform men in ultra-long-distance open-water swims. Diana Nyad became the first person to swim the 110.86 miles between Cuba and Florida in 52 hours and 54 minutes. Female swimmers also hold the average time records and overall channel records for the Catalina Channel swim, featuring a 7 minutes faster average time for women.

Biomechanics and Injury

Estrogen and progesterone elevate your core temperature and alter thermoregulation. Unacclimated women struggle more initially in hot environments, but given up to two weeks of heat acclimation, your heat-tolerance increases surpass men's. At high altitudes, such as the 14,109 feet elevation at Pikes Peak in Colorado, you burn even more fat compared to sea level. Your average core temperature sits at 97.8 degrees compared to 97.4 in men, while your average hand temperature rests at 87.2 degrees compared to 90 in men.

Wider hips required for childbirth increase the Q-angle in women, predisposing you to biomechanical alignment issues and higher rates of knee injuries. The wider female pelvis increases the Q-angle between your quadriceps and patellar tendon, leading to knock-knees, pronated feet, and hypermobile tissues. This structural difference makes you significantly more vulnerable to chronic knee pain and acute ligament tears. Your average Q-angle measures 15.8 degrees compared to 11.2 degrees for men, leaving young female athletes up to seven times more likely to tear the anterior cruciate ligament than boys.

2. Demystifying and Mastering Your Menstrual Cycle

The follicular phase runs from days 1 to 14, when estrogen and progesterone remain low and your physiology closely mirrors a man's. Progesterone then surges past estrogen during the luteal phase from days 15 to 28, peaking five days before menstruation.

The menstrual cycle divides into low- and high-hormone phases that dictate metabolic needs, fluid regulation, and recovery demands.

High levels of female hormones during the luteal phase make building and maintaining muscle mass significantly harder. Estrogen reduces the anabolic capacity of muscles. Progesterone increases the catabolic breakdown of tissue. This limits your amino acid access during hard efforts. You must consume specific amino acids before and immediately after exercise to trigger muscle repair.

• Take in protein high in leucine or branched-chain amino acids before exercise
• Replace protein within 30 minutes after exercise
• Consume 20 to 25 grams of protein within 30 minutes of finishing a session
• Aim for 0.9 to 1 gram of protein per pound per day overall

Estrogen alters carbohydrate and fat burning capabilities. It reduces your body's ability to burn carbs. It increases fat burning to save glycogen stores. This process drives starchy and sweet food cravings before your period. Metabolism naturally experiences a 5 to 10 percent uptick in the days before bleeding. You burn 100 to 200 additional calories during the premenstrual period.

• Aim for a combination of 10 to 15 grams of protein and 40 grams of carbohydrates before any workout longer than 90 minutes
• Consume 40 to 50 grams of carbohydrates combined with protein and fat per hour during long workouts
• Consume about 0.45 gram of carbohydrate per pound of body weight per hour in the high-hormone phase
• Consume about 0.35 gram of carbohydrate per pound of body weight per hour in the low-hormone phase

High premenstrual hormones alter fluid-regulating chemicals in the body. Estrogen increases vasopressin to retain water and constrict blood vessels. Progesterone competes with aldosterone to reduce total-body sodium retention. This hormonal interplay reduces plasma volume by up to 8 percent. The resulting thicker blood makes exercise feel much harder.

Amanda Tortorici, a 33-year-old Brazilian jujitsu competitor, utilized preplanning protocols with magnesium, zinc, aspirin, and omega-3s to eliminate preperiod bloat. She successfully dropped weight for a last-minute tournament.

Heat Stress

Progesterone elevates core body temperature and lowers blood volume. These changes increase the risk of heat stress and hyponatremia during endurance events. Lower blood volume and progesterone-induced sodium shedding impair your ability to sweat and cool yourself. You require specific pre-hydration and sodium-loading strategies when exercising in the heat.

• Preload on sodium the night before with a high-sodium broth such as chicken soup
• Mix 7.7 grams of sodium citrate and 4.5 grams of sodium chloride per liter for a homemade hydration drink
• Drink a large bottle of a low-carbohydrate hydration drink containing no more than 9 grams of carbohydrate per 8 ounces every hour while exercising in the heat

Menstrual cramps, headaches, and digestive distress stem from chemical releases and rapid hormone shifts. Uterine contractions are driven by prostaglandins. These chemicals can spill over into the bowels and cause gastrointestinal distress. Headaches occur when estrogen drops right from its peak. In a 2014 ESPN The Magazine survey, 50 percent of polled athletes reported menstrual cramps affected their game.

• Take magnesium, omega-3 fatty acids, and low-dose 80-milligram aspirin in the 5 to 7 days before your period starts to reduce cramp-causing prostaglandins
• Eat nitric oxide-rich foods such as beets, pomegranate, watermelon, and spinach in the days leading up to your period to prevent headaches

Contraceptives and RED-S

Hormonal contraceptives can hinder athletic performance. They reduce muscle mass gains and introduce severe health risks like blood clots. Oral contraceptives maintain artificially high systemic hormone levels that mimic the luteal phase. This state suppresses natural muscle recovery and aerobic capacity. Women not taking oral contraceptives see a 40 to 60 percent greater gain in muscle mass compared to those on the Pill. These medications also increase the risk of deep vein thrombosis and pulmonary embolisms, especially during travel.

Australian professional road cyclist Chloe McConville suffered life-threatening pulmonary embolisms and dangerously low testosterone. A progesterone-only implant had suppressed her ovaries after she stopped taking the Pill. A case study documented 10 hours of continuous travel that triggered severe blood clots in a similar setting.

Inadequate nutrition and low-carbohydrate diets in active women trigger relative energy deficiency in sport. Unlike men who thrive on low-carb diets by increasing testosterone, you respond to a hypocaloric state by dropping estradiol and elevating cortisol. This survival mechanism signals your body that a famine is occurring. It shuts down reproductive hormones regardless of body fat percentage, and women can still experience menstrual dysfunction within a 25 to 30 percent body fat range.

In a survey of over 300 ultra-marathoners, 92.5 percent had never heard of the female triad or RED-S. One-third had eating disorders, and half restricted calories.

3. Moving Through Menopause

Falling estrogen and progesterone levels during perimenopause and menopause alter metabolism, protein synthesis, and thermoregulation, requiring specialized nutritional and recovery adjustments.

The transition lasts five to ten years. You reach menopause between the ages of 48 and 55. During this time, declining hormones alter your body composition and metabolic response.

When researchers had 41 women pedal stationary bikes for 45 minutes, postmenopausal participants burned 33 percent less fat than younger women. When adjusted for total lean body mass, they still burned 23 percent less fat. You rely more heavily on limited carbohydrate stores and face increased insulin resistance.

Postmenopausal women metabolize fructose much less effectively than premenopausal women. British researchers first connected postmenopausal women and fatty acids after fructose beverages in the 1960s. Instead of storing excess energy from fructose as subcutaneous fat in hips and thighs, you create circulating fatty acids that cause high triglycerides.

Claire Lange, a 67-year-old Ironman athlete, suffered from fatigue, GI distress, and poor recovery while fueling with fructose-heavy sports drinks and gels. Her tailored plan targeted 1,835 to 2,020 baseline calories per day and 120 to 130 grams of protein.

You can prevent these issues with specific dietary actions:

• Avoid fructose-based drinks, gels, and bars.
• Switch carbohydrate sources to nutrient-dense, complex carbs, fruits, and veggies outside of training.
• Separate fueling from hydration during exercise to minimize GI issues.

Metabolic and Structural Shifts

Postmenopausal women experience age-related catabolism where muscle breakdown outpaces synthesis. Declining estrogen makes you less reactive to the muscle-making stimulus of resistance training and protein consumption. Left unchecked, your bone density can decline by up to 20 percent in the 5 to 7 years following menopause. This leaves approximately one in two women over age 50 vulnerable to breaking a bone because of osteoporosis.

Tracy Paxton, a 50-year-old vegan triathlete, suffered from diminishing muscle mass and strength despite a clean, plant-based diet, intense weight lifting, and HIIT. Because plant proteins like soy lack sufficient leucine, vegan athletes struggle with muscle recovery. It takes 50 grams of soy protein to match the biological effect of 25 grams of whey protein. Tracy restructured her plan to include branched-chain amino acids before and after training, leading to improved body composition, pacing, and strength.

You must adapt your protein and nutrient intake:

• Consume 15 grams of whey isolate or 9 grams of BCAAs 30 minutes before training.
• Consume 25 grams of mixed whey isolate and casein within 30 minutes postexercise.
• Consume another 20 to 25 grams of whey isolate and casein 2 hours after training.
• Have 10 to 15 grams of protein before bed.
• Top off the diet with BCAAs before and after each exercise session.
• Focus on food quality to increase the leucine content of muscles.
• Get a baseline bone-density scan done.

Without estrogen to govern the autonomic nervous system, your biological safeguards against overheating become sluggish. Postmenopausal women sweat less, feel less thirst, and reach higher core temperatures than younger women.

You can manage thermoregulation and daily movement with these practices:

• Use precooling by drinking an icy, low-sugar electrolyte drink.
• Add 1/16 teaspoon of salt to 20 ounces of water, or use a low-carbohydrate electrolyte drink.
• Rely on watery fruits, vegetables, protein drinks, tea, and mineral waters for daily hydration.
• Accumulate an average of an hour a day of physical activity to minimize weight gain.
• Set a computer alarm to prompt movement for 2 minutes every hour on the hour.

Sleep and Brain Health

Plummeting levels of progesterone and estrogen disrupt sleep architecture and core temperature regulation. Sixty percent of postmenopausal women complain of problems with insomnia. Progesterone provides sedative effects, while estrogen increases REM sleep, assists serotonin metabolism, and helps regulate core temperature. Withdrawal from these hormones causes nighttime cortisol spikes, hot flashes, and reduced melatonin effectiveness.

Hormonal drops also trigger widespread forgetfulness, anxiety, and depressive symptoms. The Study of Women’s Health Across the Nation tracked 12,400 women. While 31 percent of premenopausal participants experienced forgetfulness, 44 percent of early or late perimenopausal women and 42 percent of menopausal women experienced it. Estrogen increases serotonin and dopamine while inhibiting cortisol.

You can protect your sleep and cognitive function using targeted remedies:

• Establish a regular bedtime.
• Eliminate light and screens from the bedroom and keep the room temperature cool.
• Avoid alcohol and caffeine to mitigate hot flashes and anxiety.
• Drink an ice-cold glass of Montmorency tart cherry juice concentrate 30 minutes before bed.
• Take 400 milligrams of valerian extract before bed.
• Use 0.3 to 1.0 milligram of melatonin 30 minutes before bed if temperature-related sleep issues persist.
• Use strategically placed BCAAs before and after training to cross the blood-brain barrier and support the central nervous system.
• Try tart cherry juice and valerian to improve sleep.

4. Pregnancy, Fueling, and Body Composition

Pregnancy and everyday fueling require abandoning calorie restriction and intermittent fasting in favor of nutrient timing and protein distribution tailored to female hormonal profiles.

Pregnancy and Training

Exercising during pregnancy is safe, healthy, and beneficial for both the mother and the developing baby, contrary to outdated restrictive guidelines. Physical activity during pregnancy prevents excessive weight gain, reduces the risk of gestational diabetes, boosts mood, improves posture, and preps the body for labor. For the baby, it supports healthy blood vessels, endocrine system development, and placenta growth without increasing miscarriage risks.

Stacy Sims discovered she was pregnant right before the XTerra Maui race, raced anyway, and finished in the top 10.

Certain medical conditions require pregnant women to completely avoid exercise to protect their health and the baby's safety. The author outlines specific high-risk conditions and complications where physical activity is strictly prohibited, ranging from ruptured membranes and preeclampsia to multiple high-risk factors like placenta previa.

• Engage in 30 to 45 minutes of moderate physical activity most days a week.
• Include cardio exercises like running, cycling, elliptical training, walking, and swimming.
• Add resistance training two times a week focusing on upper and lower body strength with lower weights and higher reps.
• Avoid exercise if you have ruptured membranes, preeclampsia, a stitch in the cervix, or a twin pregnancy.
• Avoid exercise if at higher risk for premature labor, placenta previa, bleeding in the second or third trimester, significant heart or lung disease, previous miscarriage or premature birth, or poorly controlled systemic disease.

Pregnant women do not need to literally eat for two in terms of massive caloric increases, but they do require specific key nutrients and extra hydration. The intestines adapt during pregnancy to absorb more nutrients from the same amount of food. Therefore, caloric intake only needs a modest increase, while essential micronutrients and hydration must be carefully managed to support blood volume expansion and fetal development.

• Consume about 100 extra calories a day in the first trimester and 300 extra calories a day in the second and third trimesters.
• Get at least 400 micrograms of folate daily before pregnancy and during the first 12 weeks, increasing to 600 micrograms daily during pregnancy.
• Aim for 75 to 100 grams of protein per day.
• Consume 1000 mg of daily calcium, 27 mg of iron, 770 micrograms of vitamin A, 85 mg of vitamin C, 600 IU of vitamin D, 1.9 mg of vitamin B6, and 2.6 micrograms of vitamin B12.

Nutrition and Somatotypes

Women should identify their natural somatotype and frame size to work with their physiology rather than chasing an arbitrary scale weight. Body weight varies widely among athletes, and genetic somatotypes dictate how easily someone builds muscle or stores fat. Tracking body composition and understanding natural frame size provides a healthier and more accurate measure of fitness than standard weight charts.

Professional cyclo-cross racer Katie Compton weighed up to 172 pounds, struggled to get down to the low 130s which caused thyroid problems, and ultimately found success by accepting her body type and focusing on cyclo-cross.

Calorie counting and intermittent fasting are counterproductive for women, as they spike cortisol, increase hunger, and damage metabolic health. The traditional formula equating 3,500 calories to a pound is false, and calorie restriction triggers stress hormones that promote fat storage and muscle breakdown. Instead, women should focus on food quality, eating low on the food chain, and proper nutrient timing.

Cammie Urban and her daughter were cutting calories down to 1,300 a day, losing muscle and power; after increasing intake to about 2,300 calories with proper nutrient distribution, Cammie became leaner and won a 2015 masters world championship title.

Front-loading carbohydrates in the morning and emphasizing protein in the afternoon and evening optimizes glycogen storage, repair, and body composition. Female bodies handle carbohydrates better during the early parts of the day when systems are primed for glucose, while protein is essential in the afternoon and evening to support muscular repair and cellular processes during sleep.

• Identify your somatotype as ectomorph, mesomorph, or endomorph.
• Measure the distance between the two little bones on either side of your elbow at a 90-degree angle to determine frame size.
• Step off the scale for at least a month and rely on how clothes fit and how you feel, or test body composition via DXA.
• Stop counting calories and avoid intermittent fasting.
• Eat food recognized as coming from the earth, choosing local and organic when possible.
• Take a small protein and carb snack before morning exercise to counter high morning cortisol.
• Consume 30 grams of protein or 5 to 7 grams of BCAAs within 30 minutes of finishing a training session.
• Front-load calories and complex carbohydrates toward the beginning or middle of the day.
• Emphasize quality protein midafternoon through the evening to aid nighttime muscular repair.
• Choose foods moderate to low on the glycemic index and combine carbohydrates with protein to moderate blood sugar fluctuations.

Conclusion

Women are not small men. Training, fueling, and recovery protocols must respect the unique architecture of female physiology across all life stages. You achieve optimal health and peak athletic performance by synchronizing your lifestyle with your hormonal fluctuations rather than fighting them.

1. Reject scaled-down male training plans and consume adequate calories and protein to support your distinct metabolic needs.
2. Align your high-intensity workouts and recovery strategies with your specific menstrual cycle phases or hormonal shifts during menopause.
3. Prioritize heavy resistance training and explosive plyometrics to protect your bone density and lean muscle mass as you age.
4. Fuel your workouts with targeted real-food nutrition and precise hydration strategies instead of relying on synthetic supplements and restrictive diets.
5. Listen to your body and honor your recovery demands to build lasting resilience, strength, and vitality throughout your lifespan.

10 Key Ideas

1. Female physiology possesses unique biological characteristics across muscle composition, cardiovascular output, thermoregulation, and biomechanics that demand specific athletic protocols.
2. The menstrual cycle divides into low- and high-hormone phases that dictate metabolic needs, fluid regulation, and recovery demands.
3. Hormonal contraceptives can hinder athletic performance by reducing muscle mass gains and introducing severe health risks like blood clots.
4. Falling estrogen and progesterone levels during perimenopause and menopause alter metabolism, protein synthesis, and thermoregulation, requiring specialized nutritional and recovery adjustments.
5. Plummeting levels of progesterone and estrogen disrupt sleep architecture, core temperature regulation, and cognitive function.
6. Exercising during pregnancy is safe, healthy, and beneficial for both the mother and the developing baby, contrary to outdated restrictive guidelines.
7. Women should identify their natural somatotype and frame size to work with their physiology rather than chasing an arbitrary scale weight.
8. Calorie counting and intermittent fasting are counterproductive for women, as they spike cortisol, increase hunger, and damage metabolic health.
9. Front-loading carbohydrates in the morning and emphasizing protein in the afternoon and evening optimizes glycogen storage, repair, and body composition.
10. Training, fueling, and recovery protocols must respect the unique architecture of female physiology across all life stages.