Dr. Stacy Sims: Female-Specific Exercise & Nutrition for Health, Performance & Longevity
22 Jul 2024 (2 months ago)
Dr. Stacy Sims
- This episode of the Huberman Lab podcast features Dr. Stacy Sims, an exercise physiologist and nutrition scientist specializing in women's health and fitness. Dr. Sims has conducted extensive research on the differences in training and nutrition needs between men and women, leading to the development of new protocols for both professional athletes and the general public.
- The episode focuses on how hormones and the menstrual cycle impact nutrition and fitness needs in women at different stages of life, including the menstrual cycle, perimenopause, and menopause. It also explores female-specific nutrition and training strategies that are independent of hormones, such as the evidence suggesting that women may not benefit from fasted training.
- Dr. Sims emphasizes the importance of tailoring training programs to individual needs, considering not only gender but also specific life stages and goals. She highlights the universal principles of nutrition and training that apply to both men and women while also emphasizing the unique needs of women, providing listeners with actionable insights to optimize their health and fitness.
Sponsors: Maui Nui, Eight Sleep & Waking Up
- This chapter of the podcast acknowledges the sponsors who support the show. The first sponsor is Maui Nei Venison, which provides high-quality, nutrient-dense venison products. The speaker emphasizes the importance of consuming adequate protein, especially for muscle repair and overall health, and highlights Maui Nei Venison's high protein-to-calorie ratio. They also recommend their products, including steaks, ground venison, bone broth, and jerky.
- The second sponsor is Eight Sleep, a company that makes smart mattress covers with temperature control and sleep tracking features. The speaker emphasizes the importance of regulating body temperature for optimal sleep and highlights how Eight Sleep's mattress covers can help achieve this. They also mention the benefits of the Pod 4 Ultra model, which includes improved cooling and heating, sleep tracking, and snoring detection.
- The final sponsor is Waking Up, a meditation app that offers guided meditations, mindfulness trainings, yoga, and other resources. The speaker shares their personal experience with meditation and its benefits, including improved focus, stress management, and mood regulation. They highlight the app's diverse offerings and its ability to help users maintain a consistent meditation practice.
Intermittent Fasting, Exercise & Women
- Intermittent fasting (IF) and time-restricted feeding (TRF) can have different impacts on men and women. While IF, with long fasting periods, can be beneficial for men, it can be detrimental for active women due to their higher oxidative fiber content.
- Women are already metabolically more flexible than men due to their higher oxidative fiber content. This means they can utilize free fatty acids more efficiently for energy, making IF less necessary for improving metabolic flexibility.
- IF can increase stress in women, leading to elevated cortisol levels and a disruption of hormonal balance. This can negatively impact thyroid function, luteinizing hormone production, and overall endocrine health. TRF, aligned with circadian rhythms, is generally a better approach for women, promoting better cognitive function, thyroid health, and overall well-being.
Cortisol & Circadian Rhythm, Caffeine & Training
- Cortisol and Circadian Rhythm: Cortisol levels peak about half an hour after waking up. For women, this peak in cortisol, combined with a fasted state, can lead to a heightened sympathetic drive, making it difficult to access parasympathetic responses throughout the day. This can contribute to feelings of being tired but wired and may have negative implications for weight management.
- Intermittent Fasting and Women: Intermittent fasting or time-restricted feeding may not be advantageous for women unless it is carefully aligned with their circadian rhythm. This is because the fasted state can exacerbate the stress response, particularly when combined with exercise.
- Fasted Training and Caffeine: Training in a fasted state, especially with caffeine, further increases the sympathetic drive in women. This can lead to a more intense stress response, potentially hindering performance and recovery. Additionally, fasted training can limit the ability to achieve high-intensity workouts, as women may not have the necessary fuel to reach their target intensity levels.
Reps in Reserve, Rate of Perceived Exertion (RPE); Age & Women
- Reps in Reserve (RIR) and Rate of Perceived Exertion (RPE) are valuable tools for quantifying exercise intensity. RIR refers to the number of repetitions you could complete beyond your current set, while RPE is a subjective scale of how hard you perceive the exercise to be.
- RIR and RPE are particularly useful for heavy compound lifts like squats and deadlifts. They provide a more nuanced measure of intensity than simply using percentages of one repetition maximum (1RM), which can be dangerous for untrained individuals.
- For women, training with RIR is crucial, especially as they age. During perimenopause and menopause, estrogen levels decline, impacting strength and power. Training with 2-3 reps in reserve helps women maintain strength and power by stimulating the central nervous system, which is essential for muscle growth and adaptation. This approach is more effective than lifting to fatigue, which primarily targets muscle hypertrophy.
Pre-Training Meal & Brain, Kisspeptin
- Pre-workout nutrition is crucial for women's health and performance. Dr. Sims emphasizes that fasting and intense training can negatively impact women's bodies, particularly their lean mass. She recommends a pre-workout meal consisting of 15 grams of protein for strength training and 30 grams of carbohydrates for cardio sessions. This small amount of fuel helps to stimulate the hypothalamus, protect kisspeptin neurons, and prevent the body from entering a catabolic state.
- The focus should be on brain health and hormonal balance, not just calorie counting. Dr. Sims highlights the importance of understanding how pre-workout nutrition impacts the brain and its ability to generate intensity, blunt cortisol, and optimize training adaptations. She emphasizes that the brain's perception of energy levels is crucial for maintaining lean mass and avoiding a catabolic state.
- Calorie counting can be detrimental to mental health and lead to disordered eating. Dr. Sims cautions against the dangers of excessive calorie counting, which can lead to obsessive behaviors and potentially contribute to eating disorders. She advocates for a more holistic approach to nutrition that prioritizes brain health and overall well-being.
Post-Training Meal & Recovery Window
- Post-training nutrition is crucial for women, especially within a specific window. Women in their reproductive years need around 35 grams of high-quality protein within 45 minutes after a resistance training session, while post-menopausal women require 40-60 grams. This is because women's metabolisms return to baseline faster than men's, meaning they have a shorter window to prevent muscle breakdown and initiate repair.
- Carbohydrate intake is also important for women, but the timing is less critical. Women should aim for approximately 3 grams of carbohydrates per kilogram of body weight within 2 hours of finishing their workout. This helps replenish glycogen stores, which are depleted during exercise.
- Real food is preferred over supplements. While protein supplements can be helpful, consuming a balanced meal after training provides not only protein but also essential nutrients like magnesium, potassium, and sodium, which are crucial for recovery and overall health.
Sponsor: AG1
- Dr. Stacy Sims has been taking AG1 for over 10 years and believes in its benefits, which is why she partnered with them to sponsor her podcast.
- She emphasizes the importance of consuming unprocessed or minimally processed foods for optimal nutrition, but acknowledges that AG1 provides a nutritional insurance policy to ensure she gets all the necessary vitamins, minerals, probiotics, and adaptogens.
- AG1 is designed to support overall well-being, including mental and physical health, and Dr. Sims, along with many others, has experienced positive effects on energy levels, digestion, and sleep.
Hormones, Calories & Women
- The impact of training fasted on fat loss is debated, but experts agree that it doesn't significantly impact overall fat loss for either men or women. While some individuals prefer to train fasted, women may benefit from consuming a small amount of high-quality protein, potentially in a shake form, before training.
- Women require a higher baseline calorie intake than men due to their hormonal needs. This difference is reflected in the "tipping point" for endocrine dysfunction, which occurs at 15 calories per kilogram of fat-free mass for men and 30 for women. This higher calorie requirement is linked to the complex hormonal functions women experience, including the regulation of kisspeptin, a hormone involved in puberty and fertility.
- This difference in calorie needs is rooted in evolutionary biology and continues to be relevant in modern society. Historically, men were responsible for hunting and gathering calories, while women stayed home and were less likely to be pregnant under low-calorie conditions. This evolutionary pressure has shaped the hormonal differences between men and women, leading to the higher calorie needs for women. This difference is also reflected in the way women regulate hormones across the circadian rhythm, requiring more calories than men.
Women, Strength Improvements & Resistance Training
- Resistance training is crucial for both men and women. Dr. Sims recommends two to three resistance training sessions and two to three cardiovascular training sessions per week for optimal health and performance. She observes a positive shift in gym culture with more women engaging in weightlifting.
- Women experience rapid strength gains due to central nervous system adaptations. This is because women often haven't been exposed to the same level of neurological stress from strength training as men, leading to a quicker increase in nerve and muscle fiber activation.
- The "pump" experienced during resistance training provides a temporary visual representation of potential muscle growth. This can be reassuring for women concerned about gaining too much muscle mass, as the pump is a transient effect and doesn't necessarily reflect long-term hypertrophy.
Tool: Women & Training Goals by Age Range
- Women in their 20s and 30s: Focus on learning proper movement patterns and complex exercises. Aim for 3-4 resistance training sessions per week, incorporating compound movements and working to failure. Include 1-2 high-intensity sessions, such as sprint intervals or HIIT, either at the end of a resistance training session or on separate days.
- Women in their 30s and 40s: Shift focus to heavier compound movements and periodization, building strength and muscle mass. Continue with 3-4 resistance training sessions per week, incorporating 1-2 high-intensity sessions.
- Women 40 and older: Prioritize strength training with compound movements, aiming for at least 3 sessions per week. Include 1-2 high-intensity sessions and 1 HIIT session. Focus on proper form and technique due to increased risk of injury.
- All age groups: Consider splitting training into upper and lower body sessions or performing full-body workouts depending on time constraints. Working to failure is recommended for younger women to maximize muscle growth, while older women should focus on heavier weights to build strength and improve cognitive function.
Women, Perimenopause, Training & Longevity
- Training for longevity should be tailored to age and sex. Younger women should focus on strength training to failure to build muscle and strength. As women age, they should prioritize strength training with heavier weights and fewer repetitions, leaving some repetitions in reserve. This is because the nervous system weakens with age, and heavier lifting helps maintain neuromuscular connections.
- Perimenopause is a significant turning point for women's health and fitness. This period, typically occurring in the late 40s and early 50s, is marked by hormonal changes that affect every system in the body. These changes can lead to increased body fat, sleep disturbances, and a higher risk of soft tissue injuries like frozen shoulder and plantar fasciitis.
- Women should prioritize heavy lifting and polarizing training during perimenopause. This approach helps prepare the body for the hormonal changes and stresses associated with this period. By focusing on strength training and polarizing training, women can build resilience and mitigate the negative effects of perimenopause. Men, on the other hand, experience similar changes in their late 50s and early 60s, giving them a wider window to implement these strategies.
Women & Training for Longevity, Cardio, Zone 2
- Women not on hormone replacement therapy should be cautious about excessive cardiovascular exercise, especially moderate-intensity workouts. This is because moderate intensity can lead to a spike in cortisol without triggering the desired post-exercise hormonal responses (growth hormone and testosterone) that help with body composition and longevity.
- High-intensity interval training (HIIT) is more beneficial for women in this age group than moderate-intensity workouts. True HIIT involves short bursts of intense effort (80% or more of maximum effort for 1-4 minutes or full gas for 30 seconds or less) with adequate recovery time. This type of training helps to lower cortisol, improve body composition, and enhance metabolic control, insulin sensitivity, and brain health.
- While long-duration, low-intensity exercise (Zone 2) can be beneficial for mental health and enjoyment, it is not optimal for maximizing longevity and body composition. Resistance training should be the foundation of a training program for women in this age group, with HIIT added for optimal results.
Tools: How to Start Resistance Training, Machines; Polarized Training
- Overcoming Resistance Training Barriers: Many women, even those who are physically active, struggle with resistance training. This is often due to a lack of confidence in performing complex compound movements like squats and deadlifts. The intimidating gym environment and unfamiliar equipment can also be deterrents.
- Accessible Entry Points: To overcome these barriers, Dr. Sims recommends starting with bodyweight exercises or adding resistance with a weighted backpack. She also suggests utilizing online resources like Kelly Starett's mobility programs or programs specifically designed for women or those over 40. Machines, particularly plate-loaded machines, offer a controlled and safe way to begin resistance training.
- Polarized Training: Dr. Sims advocates for polarized training, which involves alternating between high-intensity resistance training sessions (3-4 days per week, 45-75 minutes) and low-intensity recovery activities like walking or jogging. This approach maximizes both muscle strength and cardiovascular benefits.
- High-Intensity Cardiovascular Work: For cardiovascular training, Dr. Sims recommends true sprint interval training, such as 30-second bursts on an assault bike followed by recovery periods. This intense approach is more effective than prolonged moderate-intensity exercise for improving cardiovascular health and longevity.
Perform with Dr. Andy Galpin Podcast
- The Huberman Lab team has launched a new podcast called "Perform with Dr. Andy Galpin," hosted by exercise science and human performance expert Dr. Andy Galpin.
- This podcast focuses on topics such as muscle and strength building, cardiovascular health improvement, and optimizing recovery and sleep for performance.
- Dr. Galpin is a highly knowledgeable and engaging educator, making the podcast a valuable resource for anyone interested in human performance.
Menstrual Cycle & Training, Tool: Tracking & Individual Variability
- The menstrual cycle significantly impacts training, both psychologically and physiologically. While some research suggests no effect, these studies often have limited sample sizes and focus on women with "normal" cycles, neglecting the individual variability of women's experiences.
- Tracking one's own cycle is crucial for understanding individual patterns and optimizing training. The low hormone phase (before ovulation) is generally optimal for high-intensity training and pushing limits due to increased stress tolerance and immune function. The high hormone phase (after ovulation) can be more challenging, with potential for increased inflammation, carbohydrate intolerance, and sympathetic drive.
- Nutrition plays a vital role in managing the hormonal fluctuations of the menstrual cycle. The luteal phase, in particular, requires increased carbohydrate and protein intake to support tissue building and offset potential stress responses. However, individual variability in ovulation and hormone levels makes it essential to track personal patterns and adjust nutrition accordingly.
Tool: 10-Minute Rule; High-Intensity Training & Menstrual Cycle
- The 10-Minute Rule: Dr. Sims recommends a "10-minute rule" for determining workout intensity during different phases of the menstrual cycle. If you wake up feeling awful, give yourself 10 minutes to see if you can hit your desired intensity. If not, adjust your workout to something less taxing. This is because our bodies have a limited capacity for stress, and pushing too hard when feeling low can lead to increased sympathetic drive and negatively impact recovery.
- High-Intensity Training and the Menstrual Cycle: There is no evidence to support the myth that high-intensity resistance training is detrimental to female hormone cycles. This myth likely stems from a combination of cultural influences and a lack of understanding about proper nutrition for athletes. Historically, women in sports were often discouraged from discussing their menstrual cycles, and there was a pressure to suppress them to be seen as more "masculine" and capable of competing with men. This led to inadequate fueling and energy availability, which could disrupt hormone cycles.
- The Importance of Proper Fueling: The key to avoiding menstrual cycle disruptions during high-intensity training is proper fueling. Women need to ensure they are consuming enough calories and nutrients to support their training demands. This will help maintain healthy hormone levels and prevent the negative consequences of energy deficiency.
“Train Hard & Eat Well”; Appetite, Nutrition & Menstrual Cycle
- Calorie balance is crucial for women's menstrual health: Maintaining a caloric balance or a slight surplus is essential for women to avoid menstrual irregularities, even with intense training. A small calorie deficit (150-200 calories) away from training can support fat loss without impacting lean mass or recovery.
- Fueling around exercise stress is critical: Women should prioritize fueling adequately around exercise to support recovery and adaptation. This is especially important for women who have been conditioned to restrict their food intake. The mantra "train hard, eat well" emphasizes the importance of fueling appropriately for optimal results.
- Hormonal fluctuations impact appetite and fuel needs: Estrogen levels fluctuate throughout the menstrual cycle, influencing appetite. High estrogen levels before ovulation suppress appetite, while a dip in estrogen after ovulation increases hunger. Progesterone also plays a role in cravings, as the body requires more calories during this phase. This highlights the importance of understanding and adjusting fuel intake based on the menstrual cycle phase.
Oral Contraception, Hormones, Athletic Performance; IUD
- Oral contraceptive pills (OCPs) have a significant impact on the body, not just reproductive health. OCPs are designed to downregulate ovarian function, leading to a different hormone profile than someone who naturally cycles. This can affect athletic performance, inflammatory responses, and even brain function.
- The effects of OCPs vary depending on the type and dosage. Monophasic OCPs are the most common, with a consistent dose of estrogen and progesterone. Higher estrogen doses can increase muscle mass but not strength, which can be detrimental for power athletes. Different generations of progestin have varying effects on mood and athletic performance.
- There is limited research on the long-term effects of OCPs, especially in young girls. A recent study found that OCPs can increase fear and anxiety in women, and the effects on developing brains are unknown. There is a need for more research to understand the full impact of OCPs on women's health and performance.
- Other forms of contraception, like IUDs, may be less problematic for athletes. Copper IUDs and progestin-laced IUDs do not have a systemic effect on adaptation, inflammation, or mood. They are a good option for athletes who want a long-term, low-maintenance form of contraception.
Evaluating Menstrual Blood, PCOS; Hormones & Female Athletes
- Menstrual blood is a valuable indicator of endocrine and endometrial health. It can be used to detect conditions like HPV and PCOS, and new at-home tests are emerging to provide women with more information about their health.
- PCOS is a complex condition with a high prevalence, but its true incidence is debated. Some cases may be "rebound PCOS" after discontinuing oral contraceptives, while others may be related to increased carbohydrate intake and follicular stimulation. PCOS can impact fertility and is common in Olympic athletes due to its association with higher androgen levels.
- The relationship between exercise and hormone levels in women is complex and requires further research. While studies have shown that stress can increase cortisol and testosterone in women, more research is needed to understand the specific effects of high-intensity training and competitive scenarios on hormone levels and psychology in women.
- Hormonal changes in female athletes during intense training blocks are normal and typically not severe enough to cause menstrual cycle dysfunction. Monitoring estrogen, progesterone, and luteinizing hormone levels can help athletes manage potential hormonal fluctuations and minimize the risk of amenorrhea.
Iron, Fatigue; Blood Testing & Menstrual Cycle
- Iron supplementation during menstruation: Dr. Sims recommends taking an iron supplement every other day, starting on the first day of bleeding for 10 days. This timing allows for optimal iron absorption, as the body is more receptive during menstruation. However, she emphasizes that not all women need iron supplements, as fatigue can have various causes.
- Iron levels and fatigue: While low ferritin levels (a protein that stores iron) can contribute to fatigue, it's not the only factor. Dr. Sims suggests that a ferritin level of 50 is ideal for active women, and supplementation can help those with lower levels reach this target.
- Optimal timing for blood tests: Dr. Sims recommends taking blood tests 5 to 7 days before the start of a woman's period (mid-luteal phase) for a comprehensive assessment of hormones and other factors. This timing provides a good indication of estrogen, progesterone, and testosterone levels, as well as inflammation markers. A second blood test on day 2 of the menstrual cycle can provide a baseline estrogen level. These two tests can capture a significant amount of relevant data about a woman's hormonal cycle.
Caffeine & Perimenopause; Nicotine, Schisandra
- Caffeine is safe for most people, but women going through perimenopause may experience increased sensitivity to its effects on blood sugar. This can lead to hypoglycemia, especially if caffeine is consumed without food.
- Nicotine, while potentially beneficial for cognitive function in older adults, is not recommended for general use due to its vasoconstrictive properties. This can negatively impact skin health, even when ingested through methods other than smoking.
- Schisandra is an adaptogen that can help regulate dopamine, serotonin, and cortisol, leading to improved focus and reduced brain fog. Dr. Sims recommends it as a natural alternative to caffeine for those seeking a cognitive boost.
Deliberate Cold Exposure & Women, Endometriosis; Tool: Sauna & Hot Flashes
- Deliberate cold exposure: While Dr. Sims enjoys the alertness and euphoric feeling associated with cold showers, ice baths, and cold plunges, she believes the benefits are similar for both men and women. However, she recommends a water temperature of around 16°C (55-56°F) for women, as colder temperatures can cause severe vasoconstriction and shutdown. This temperature is still cold enough to trigger the desired physiological changes.
- Sauna for women: Dr. Sims strongly advocates for sauna use for women, as it provides numerous benefits, including improved insulin and glucose control, enhanced heat shock protein expression, and better cardiovascular responses. Additionally, sauna use can help alleviate hot flashes and night sweats by stimulating the hypothalamus and increasing serotonin production in the gut.
- Cold exposure and endometriosis: A pilot study conducted by Dr. Sims' team suggests that deliberate cold exposure around ovulation, sustained for 10 days over three menstrual cycles, can attenuate endometriosis symptoms. This is because cold exposure can dampen inflammation, which is a key factor in endometriosis.
- Cautionary note on Wim Hof method: Dr. Sims strongly advises against combining cyclic hyperventilation with breath holds and water exposure, even in shallow water. This practice has been linked to drownings and should only be attempted on dry land, if at all. She emphasizes the importance of slow, deep breaths and proper supervision when engaging in deliberate cold exposure.
Tools: “Sims’ Protocol”: Post-Training Sauna & Performance; “Track Stack”
- Post-Training Sauna Exposure: Dr. Sims recommends a post-training sauna session for up to 30 minutes after resistance training. This practice, known as the "Sims' Protocol," promotes passive dehydration, which stimulates the production of red blood cells and increases blood volume. This, in turn, enhances cardiovascular performance and improves athletic performance.
- The "Track Stack": Dr. Sims describes a supplement stack called the "Track Stack" designed for high-intensity training. It includes caffeine, low-dose aspirin, and beta-alanine. This combination aims to increase performance by enhancing blood flow, reducing inflammation, and improving muscle contraction.
- Recovery Considerations: Dr. Sims emphasizes the importance of proper recovery after using the "Track Stack" due to its significant stress on the body. She advises against consecutive days of high-intensity training with the stack and recommends prioritizing recovery to ensure optimal adaptation.
Women, Hormones & Sleep, Perimenopause & Sleep Hygiene
- Sleep is crucial for both mental and physical health, and women's sleep needs vary across the menstrual cycle and with age. Women experience changes in sleep architecture, particularly around the mid-luteal to premenstrual phase, with less slow-wave sleep, increased latency, and more light sleep. This can contribute to mood issues due to estrogen's influence on serotonin.
- Sleep hygiene is particularly important for women during the premenstrual phase. Strategies like optimizing room temperature, limiting screen time, and considering supplements like L-theanine and GABA can be helpful.
- Menopause can significantly impact sleep quality in women. Hot flashes, night sweats, and increased sympathetic nervous system activity can disrupt sleep. Working with a sleep specialist, using adaptogens like Rhodiola and theanine, and incorporating non-sleep deep rest techniques like Yoga Nidra can be beneficial.
Supplements: Creatine, Water Weight, Hair Loss; Vitamin D3
- Supplements are not replacements for a healthy diet, but they can be beneficial additions. Dr. Sims emphasizes that supplements should be viewed as "supplements" and not "replacements" for a balanced diet. She categorizes supplements into three types: food-based supplements (like protein powder), supplements designed to achieve a specific goal (like a specific vitamin), and supplements that provide general support (like an "insurance policy").
- Creatine is a beneficial supplement for women of all ages. Dr. Sims recommends 3-5 grams of creatine monohydrate per day, preferably CreaPure, which is produced using a water-based wash and has fewer side effects than other forms. Creatine can improve brain function, mood, and gut health. While it can cause a slight increase in water weight due to water retention in the muscles, this is not necessarily a negative effect and is not experienced by all women. There is no evidence to support the claim that creatine causes hair loss.
- Vitamin D3 is crucial for overall health, especially for women. Dr. Sims highlights the importance of vitamin D3 for cardiovascular health, muscle function, brain health, and iron absorption. She recommends a daily intake of 1,000-5,000 IU, depending on factors like geographic location and sun exposure. It's important to note that sunscreen can block vitamin D production, so it's essential to balance sun exposure with sun protection.
Protein Powder; Adaptogens & Timing
- Protein powder is a good supplement for women, as it can be difficult to get enough protein through diet alone. However, it should not be used as the primary source of protein.
- Adaptogens, such as ashwagandha, holy basil (Tulsi), and medicinal mushrooms like Lion's mane and Reishi, can be beneficial for women. These adaptogens can help to reduce cortisol levels, which can be helpful for managing stress and improving sleep.
- The timing of adaptogen intake is important. Ashwagandha, Tulsi, and Reishi are best taken in the late afternoon or evening when cortisol levels naturally decline. Shishandra, which is more stimulating, can be taken in the morning for a boost in focus. It is important to consider the specific effects of each adaptogen and to cycle their use to avoid potential side effects.
Pregnancy & Training; Cold & Hot Exposure
- Pregnancy and Training: During pregnancy, a woman's body naturally reduces anaerobic capacity and increases blood volume. This means that high-intensity training should be avoided, but moderate exercise is encouraged. The focus should be on maintaining fitness levels rather than making gains. The best approach is to listen to your body and avoid activities that cause pain or discomfort.
- Cold Exposure During Pregnancy: There is no definitive answer on whether cold exposure is safe during pregnancy. Due to the potential risks of miscarriage, especially during the first trimester, it is recommended to avoid cold exposure until consulting with a healthcare professional.
- Heat Exposure During Pregnancy: Moderate heat exposure, such as hot yoga, is generally considered safe during pregnancy. This is because the slight hypoxia caused by heat can actually increase vascularization in the placenta, improving nutrient delivery to the fetus. However, extreme heat should be avoided, and pregnant women should listen to their bodies and leave hot environments if they feel uncomfortable.
- Heat and Male Fertility: Heat exposure is detrimental to sperm viability and can negatively impact male fertility. Cooling the testicles can actually increase testosterone levels, likely due to vasoconstriction followed by vasodilation.
- Temperature and the Body: It is important to consider both the surface of the body and the brain's response when considering the effects of heat and cold. The body's response to deliberate heat or cold exposure is a process, not a single event.
Tool: Women in 50s & Older, Training & Nutrition for Longevity
- For women over 50, the most efficient way to train for maximum healthspan and lifespan benefits is through a combination of jump training, heavy resistance training, and sprint interval training. This type of training helps to improve bone mineral density, which is crucial as women lose about one-third of their bone mass at the onset of menopause.
- Jump training, in particular, has been shown to be effective in increasing bone density. Studies have shown that women who engage in jump training for four months can see a significant improvement in their bone density, even moving from osteopenic to normal bone density.
- In addition to exercise, protein intake is essential for women over 50. Dr. Sims recommends a protein intake of 1 to 1.1 grams per pound of body weight, or 2 to 2.3 grams per kilogram of body weight. This may seem like a lot of protein, but it is necessary to build and maintain muscle mass, which is crucial for longevity.
Tool: Women in 20s-40s & Training, Lactate
- For women in their 20s to 40s, the most efficient way to train for health, vigor, and longevity is to prioritize resistance training. This doesn't have to be heavy lifting, but it should be varied to keep things interesting and promote strength and muscle growth.
- Lactate production is crucial for brain health and cognitive function in women. Since women tend to be more oxidative, they may not naturally produce as much lactate. Engaging in high-intensity exercise, like sprints, helps stimulate lactate production, which can protect against cognitive decline and Alzheimer's disease.
- Starting high-intensity training early in life is beneficial for women. This helps to develop and maintain glycolytic fibers, which are essential for lactate production. This early exposure to lactate can have long-term benefits for brain health.
Tool: What is High-Intensity Training?, Cardiovascular Sets & Recovery
- High-intensity training (HIIT) is not just a hard workout. It involves short bursts of intense effort followed by periods of recovery. Examples include track intervals (400m sprints with recovery) and gym circuits with short, intense exercises and rest periods.
- HIIT is different from resistance training. HIIT focuses on cardiovascular exertion and improving your body's ability to recover quickly, while resistance training aims to build muscle and strength.
- Sprint interval training (SIT) is a more intense form of HIIT. It involves all-out effort for 30 seconds or less, followed by longer recovery periods (2-3 minutes). This type of training pushes your body to its limits and promotes rapid recovery.
Training for Longevity, Cellular & Metabolic Changes
- The focus should be on creating strong external stress to trigger adaptations, not just aesthetics or body composition. This means moving beyond the typical "get swole" or "lose body fat" mentality and focusing on creating changes at the cellular and metabolic level.
- High-intensity exercise can lead to epigenetic changes in muscle cells, increasing the number of GLUT4 transporters. This allows for greater glucose uptake without insulin, improving metabolic efficiency.
- High-intensity exercise also triggers an acute inflammatory response that the body learns to overcome. This is particularly important for women as they age and experience a decline in estrogen, which has anti-inflammatory properties. This helps to prevent the accumulation of visceral fat, which can occur as a result of increased free fatty acids and reduced inflammatory response.
Nutrition, 80/20 Rule
- Dr. Sims recommends a balanced diet for women, emphasizing quality protein (1.1-1.2 grams per pound of body weight), diverse fruits and vegetables, and complex carbohydrates. She prefers rice, oatmeal, sourdough bread, and whole grains over ultra-processed options. She acknowledges that occasional indulgences are acceptable, especially after intense training when glycogen stores are depleted.
- Dr. Sims highlights the importance of a diverse gut microbiome for women, which is influenced by dietary choices. She encourages consuming a variety of fiber-rich foods, colorful fruits, and vegetables to support gut health.
- Dr. Sims advocates for a balanced approach to fat intake, emphasizing whole food plant-based sources while acknowledging the benefits of some animal fats. She encourages consuming avocados, nuts, seeds, olive oil, and dairy products like butter and full-fat yogurt. She emphasizes that a balanced diet should be enjoyable and not restrictive.
Listening to Self
- Dr. Sims believes that the most impactful change for women's health would be for them to understand their intrinsic selves. She emphasizes the importance of listening to their bodies and cycles, as they have been bombarded with external noise and societal expectations that often overshadow their own internal signals.
- Dr. Sims emphasizes the importance of understanding the menstrual cycle and menopause as natural processes. She believes that women should be empowered to understand their bodies and cycles, allowing them to make informed decisions about their health and fitness.
- Dr. Sims believes that understanding one's body is the key to implementing external stressors, such as exercise and nutrition, in a way that is beneficial. By listening to their bodies, women can tailor their training and nutrition to their individual needs and optimize their health and performance.
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