Osteopenia and Strength Training for Women: What Happens Before Menopause

Written by Evelyn Calado, MKin, CSCS, RKin

There is a persistent misconception that bone loss is something that “just happens” after menopause. By the time many women start thinking seriously about bone density, the process of loss is already well underway.

Osteopenia and strength training are directly linked, yet most women are not told how early bone loss actually begins.

Bone health is not a passive outcome of aging. It is an active, dynamic process shaped by hormones, mechanical loading, and energy availability across the entire female lifespan.

Understanding osteopenia requires understanding one central principle: bone is living tissue, constantly undergoing remodeling through the opposing actions of osteoblasts and osteoclasts.

Bone Remodeling: The Balance Between Formation and Breakdown

At any given moment, your skeleton is not static. It is metabolically active.

• Osteoblasts are responsible for bone formation

• Osteoclasts are responsible for bone resorption

In a healthy system, these processes are tightly coupled. Bone that is broken down is replaced with new, strong bone. The integrity of your skeleton depends on the balance between these two forces.

Estrogen plays a critical regulatory role in maintaining this equilibrium.

Estrogen as a Regulator of Bone Turnover

Estrogen is not just a reproductive hormone. It is deeply involved in musculoskeletal health.

It functions, in part, by:

• Inhibiting excessive osteoclast activity

• Supporting osteoblast survival and activity

When estrogen levels are stable, bone turnover remains balanced. But when estrogen becomes low or erratic, this regulatory system begins to fail.

Estrogen does not “leach calcium from bone.” Its decline removes inhibitory control over osteoclasts, allowing bone resorption to outpace formation.

The result is a gradual reduction in bone mineral density, what we clinically recognize as osteopenia, and eventually osteoporosis if left unchecked.

Perimenopause: The Underappreciated Inflection Point

Much of the conversation around bone health focuses on postmenopause. However, perimenopause is a critical and often overlooked phase.

This is not simply a state of low estrogen. It is a state of hormonal volatility.

During perimenopause:

• Estrogen levels fluctuate unpredictably

• Progesterone exposure becomes inconsistent

• The coordination of tissue remodeling processes becomes impaired

These fluctuations influence:

• Bone turnover

• Muscle protein synthesis

• Recovery capacity

The net effect is a physiological environment that becomes increasingly catabolic, meaning tissue breakdown can begin to exceed tissue formation.

This is why bone density decline can begin before menopause is complete.

The Muscle–Bone Unit: Why Strength Matters

Bone does not exist in isolation. It is functionally linked to muscle through what is often referred to as the muscle–bone unit.

When muscle contracts, it exerts mechanical force on bone. This mechanical strain is the primary stimulus for bone adaptation.

Without sufficient loading, the body interprets bone as metabolically expensive and unnecessary, and osteoclastic activity increases accordingly.

Strength training directly targets this system.

Through high-load resistance exercise:

• Muscle force increases

• Mechanical strain on bone increases

• Osteoblast activity is stimulated

• Bone mineral density is preserved or improved

This is not a marginal effect. It is one of the most powerful non-pharmacological interventions available for maintaining skeletal integrity.

If you are unsure where to start, this is exactly where an individualized approach matters. [Start with an Initial Assessment]

Why Endurance Alone Is Not Enough

Many active women assume that being “fit” is sufficient to protect bone health. However, endurance training does not provide the same osteogenic stimulus as resistance training.

In fact, without adequate nutrition and strength work, high volumes of endurance exercise can:

• Increase cortisol and systemic stress

• Contribute to low energy availability

• Impair bone formation

Bone health requires specific, targeted mechanical loading, not just general activity.

Why Strength Training Is Essential for Women’s Bone Health

Dr. Stacy Sims is explicit. Strength training is not optional for women. It is a lifelong requirement.

General recommendations include:

• At least 2 to 3 strength sessions per week

• Emphasis on heavy resistance, not just light weights

• Inclusion of compound lifts and power-based movements

This becomes even more critical during perimenopause and beyond, when:

• Muscle mass becomes harder to maintain

• Hormonal support for tissue repair declines

• The risk of accelerated bone loss increases

Strength training is not simply about preserving aesthetics or performance. It is about maintaining structural integrity.

For most people, this requires structure, progression, and accountability. [Explore Personal Training Options]

The Compounding Effect of Muscle Loss

Muscle loss and bone loss are interconnected.

As muscle mass declines:

• Mechanical loading on bone decreases

• Bone formation signals weaken

• Risk of fragility increases

Hormonal environments during this phase can also increase muscle protein breakdown, making it harder to maintain lean mass without intentional intervention.

This creates a feedback loop:

Less muscle leads to less bone stimulus, which leads to weaker bone and higher injury risk.

Strength training interrupts this cycle.

Bone Health Is Built, Not Preserved

One of the most important reframes is this:

You are not trying to hold on to bone. You are trying to continually build and reinforce it.

Bone is responsive tissue. It adapts to the signals it receives.

• If the signal is inactivity, bone loss occurs

• If the signal is chronic stress without adequate fuel, bone loss occurs

• If the signal is heavy loading with adequate nutrition, bone strength improves

Perimenopause does not mark the end of this adaptability. It simply raises the stakes.

Final Thoughts

Osteopenia is not an inevitable consequence of aging. It is, in large part, the result of mismatched physiology, where hormonal changes are not met with appropriate mechanical and nutritional support.

Estrogen may set the stage, but behavior determines the outcome.

Strength training, done consistently and with sufficient intensity, provides the necessary stimulus to:

• Maintain bone mineral density

• Preserve lean muscle mass

• Counteract the catabolic shifts of hormonal fluctuation

For women entering perimenopause, this is not optional. It is essential.

And the earlier this foundation is built, the more resilient the system becomes over time.

This is why most of the women we work with are already incorporating structured resistance training before these changes begin. [Learn More About Hybrid Coaching]

Source

Dr. Stacy Sims, ROAR

ACL Injury Risk in Female and Youth Athletes: What Actually Matters (Part 2)

Written by Michael Crawley, BSc, BPT, CSCS

Anterior cruciate ligament injuries are a significant issue in sport, particularly among female and youth athletes. Female athletes have a significantly greater incidence of ACL injury compared to males, with research suggesting the risk may be between 2 and 8 times higher depending on the population studied (Herzberg et al. 2017).

A number of factors have been proposed to influence this increased risk. These include both extrinsic factors such as playing surface, and intrinsic factors such as biological, structural, and physical characteristics. This article focuses on the intrinsic side of the equation.

If you have not read Part 1, where we break down how ACL injuries occur and what influences risk more broadly, you can start here: ACL Injuries: How They Occur, Who Is at Risk, and Why Training Quality Matters

The key intrinsic factors that may influence ACL injury risk in the female athlete include:

• hormonal influences

• biomechanics and structural considerations

• strength and neuromuscular control

It is also important to recognize that surgery is not the only solution following an ACL injury. The appropriate approach depends on the athlete’s age, injury severity, and the presence of additional damage such as meniscal or cartilage involvement. Graft selection is also influenced by these factors and plays an important role in long-term outcomes.

Menstruation and Hormones

The menstrual cycle consists of three phases, each characterized by fluctuations in key hormones including estrogen, progesterone, and luteinizing hormone (Wojtys et al. 2002).

• Follicular phase: approximately 9 days

• Ovulatory phase: approximately 5 days, marked by peaks in estrogen and luteinizing hormone

• Luteal phase: approximately 14 to 15 days, with elevated progesterone

Research in this area remains mixed. However, several studies have reported a higher incidence of ACL injuries during the ovulatory phase compared to other phases (Wojtys et al. 2002; Herzberg et al. 2017).

Wojtys et al. (2002) demonstrated a higher number of ACL injuries, marked as X on the figure above, in a group of young female athletes during the ovulatory phase. The mechanisms behind this relationship are varied and often disputed. At the neurological level, Kumar et al. (2013) demonstrated reduced reaction time to visual and auditory stimulus between the follicular and luteal phases.

From a structural perspective, the ACL contains estrogen receptors, and cell culture research has demonstrated that estrogen can influence the ligament’s collagen composition. It is proposed that this may increase knee joint laxity. Maruyama et al. (2021) examined knee laxity across the menstrual cycle and found increased anterior knee laxity during the ovulatory phase.

However, this difference was only observed when participants were grouped into those with genu recurvatum and those without it, meaning athletes whose knees hyperextend 10 degrees or more versus those who do not. This adds another layer of complexity, as it suggests that biomechanical factors such as hyperextension may interact with hormonal factors such as higher estrogen levels rather than acting independently.

Relaxin is another important peptide hormone that has been specifically linked to injury risk in female athletes. It appears to work synergistically with estrogen, contributing to changes in ligament laxity (Berger et al. 2023; Parker et al. 2024).

Relaxin exerts its effects in two key ways:

• increases type 1 collagen degradation

• suppresses collagen synthesis

Given that ligaments are composed of approximately 40 to 50 percent type 1 collagen, this provides a plausible mechanism by which relaxin may influence ACL integrity. Alterations in the collagen structure of the ligament are one proposed explanation for increased laxity and injury risk.

Parker et al. (2024) also highlight a practical consideration. Relaxin levels tend to peak around days 21 to 24 of the menstrual cycle. In a coaching setting, this may present as an athlete reporting unexplained musculoskeletal discomfort around the knee without a clear training-related cause. This is not something to overreact to, but it can serve as a useful opportunity for education, monitoring, or short-term modification of training.

Across the cycle, these hormonal fluctuations may contribute to changes in reaction time, ligament laxity, and available joint range of motion. While some research has explored the use of oral contraceptives to regulate these hormonal variations and potentially reduce ACL injury risk (Herzberg et al. 2017), the quality of evidence remains low and is often confounded by multiple variables.

More importantly, as Parker et al. (2024) point out, oral contraceptives are not without trade-offs. While they may influence hormones such as relaxin and estrogen, there are more accessible and lower-risk interventions available. For most young female athletes, this is not where the focus should be.

Which leads into the next major factor: strength and neuromuscular training.

Strength and Neuromuscular Training

As female participation in sport has increased over the past few decades, there has been a corresponding increase in injury rates. At the same time, training age and exposure to structured strength and conditioning within a gym setting has generally lagged behind that of male athletes.

Well-rounded strength and conditioning is not only a tool to support and improve performance in sport. It can have a profound effect on robustness and coordinative qualities, helping to mitigate injury risk.

For a deeper look at how strength training should be structured for younger athletes, see: Building a Strong Foundation: The Crucial Role of Youth Strength and Conditioning

In young female athletes, several characteristics have been associated with increased ACL injury risk (Collings et al. 2022):

• lower strength ratios between hip adductors and abductors

• reduced trunk control

• higher countermovement peak force values

This highlights the importance of a complete strength and conditioning plan. As young athletes improve jumping ability and increase power output, the risk of ACL injury and other issues such as patellofemoral pain may also increase (Myer et al. 2015; Collings et al. 2022).

Training for these athletes must address several components:

• maximal strength and power

• jumping and landing mechanics and technique

• strength capacity

• energy system development

Sugimoto et al. (2016) demonstrated that neuromuscular programs that include a combination of strength training, jumping, trunk control, and coordination significantly reduce ACL injury risk in young female athletes.

Practical Exercise Examples

Below are five exercises that cover several key qualities related to performance and injury mitigation:

• Side lunge deceleration control

• Front squat

• Side plank hip abduction iso

• 1-2-1 broad jump

• Split stance press + hip hike

Adjusting variables such as volume, intensity, range of motion, and frequency can make exercises like these highly effective across a range of sports and athlete levels.

Adherence, Enjoyment, and the Training Environment

Several factors can impact adherence in young female athletes:

• time

• enjoyment

• coaching expertise

• equipment access

Research suggests that even two 30-minute sessions per week in-season can meaningfully reduce ACL injury risk, provided a more comprehensive program is completed in the off-season (Sugimoto et al. 2016).

Enjoyment and coaching quality are closely linked. Engagement in the gym setting can be a challenge, particularly for younger athletes. Incorporating competition, variability, and game-based elements can improve buy-in and training consistency.

Reaction, Coordination, and Game-Based Training

The following examples can be used to improve reaction time, coordination, and strength:

• Tennis ball reaction game

• Walking lunge with figure 8 pass

These drills can be implemented in pairs, relay formats, or with sport-specific variations. They also expose athletes to a broader range of movement patterns.

This ties closely into long-term athlete development principles, which are outlined further here:
Build the Athlete First: Why Youth Athletes Need Physical Literacy Before Sport Specialization

An additional benefit of implementing games with different constraints and equipment is the development of energy systems and exposure to a wider range of motor patterns. The importance of this is two-fold.

1. Fatigue has been shown to impact landing control and hip-to-ankle force dissipation in female athletes (Mancino et al. 2024). Improving overall capacity can enhance an athlete’s ability to maintain reaction time and landing mechanics over longer periods.

2. Game and exercise constraints can also help offset the repetitive, high-volume actions seen in many sports. This becomes even more relevant in athletes who specialize early in a single sport.

Luo et al. (2025) found that early sport specialization increases injury risk, reduces long-term performance, and negatively impacts psychological outcomes. With a creative and experienced coach, the gym setting can serve as a valuable environment to address these gaps.

That said, even with a well-informed and diligent athlete who engages in strength training and participates in multiple sports, ACL injuries can still occur.

Surgical Route and Graft Selection

When a discussion has been made and surgery is deemed the best option, the next decision is graft selection. The importance of this choice lies in the fact that it is one of the few modifiable factors (Duchman et al. 2017). For the young female athlete, variables such as sex, age, and sporting demands cannot be changed.

The main graft options include:

• Autograft: tissue harvested from the athlete’s own body. Common options include hamstring tendon (HT), bone-patellar tendon-bone (BPTB), and quadriceps tendon (QT)

• Allograft: donor tissue. Options can include tibialis anterior, Achilles tendon, hamstring, or patellar grafts (Duchman et al. 2017)

Pinheiro et al. (2022) conducted a large analysis in female athletes and found that bone-patellar tendon-bone grafts had a lower incidence of graft failure compared to hamstring grafts. This becomes more nuanced when age is considered.

Mancino et al. (2024) reported that BPTB grafts had lower re-rupture rates in females aged 15 to 20 compared to hamstring autografts. However, in athletes aged 21 and older, outcomes between BPTB and hamstring grafts were similar.

Graft revision risk is also an important consideration. Pinheiro et al. (2022) found that revision rates were 1.8 times higher in hamstring grafts compared to BPTB, increasing to 2.8 times in females under 18. This is particularly relevant, as revision surgeries tend to produce poorer outcomes compared to primary ACL reconstruction (Meena et al. 2024).

More recent evidence suggests that quadriceps tendon grafts produce comparable outcomes in terms of knee stability, functional performance, and re-tear risk (Meena et al. 2024).

Previous injury history should also influence graft selection. Lazarides et al. (2018) reported that a history of moderate to severe patellar tendinopathy was associated with increased graft failure when using BPTB grafts.

Similarly, hamstring autografts may contribute to post-surgical return-to-sport challenges (Bouzekraoui Alaoui et al. 2025), including:

• persistent strength deficits compared to the uninvolved side

• reduced maximum effective angle, a proxy for hamstring function and potential injury risk

In athletes with a history of recurrent hamstring strains or existing strength deficits, harvesting a hamstring graft from the involved side should be carefully considered. This may further complicate the already challenging process of restoring hamstring strength and function during rehabilitation.

Additional Surgical Consideration: LET

Another surgical consideration is the lateral extra-articular tenodesis (LET), which may provide additional protection against re-injury. Recent research has identified specific factors where LET can help reduce risk and may be used as an added layer of structural support (Meena et al. 2024).

These factors include:

• increased general knee ligament laxity

• high tibial slope and increased knee hyperextension

• return to high-demand sport

• younger age

These considerations are particularly relevant for the young female athlete. As discussed throughout this article, hormonal influences on ligament laxity, along with structural characteristics such as knee hyperextension, are commonly observed in this population.

Using appropriate graft selection alongside LET where indicated provides an additional layer of structural support and may improve long-term outcomes in higher-risk athletes.

Summary

There is a complex interplay between hormonal, structural, and neuromuscular factors that may increase ACL injury risk in young female athletes. While many aspects of the research still require further clarity, it is clear that both modifiable and non-modifiable factors are at play.

There are several practical approaches that can help mitigate risk while also improving performance. As participation in female sport continues to grow, appropriate exposure to education, training, and support systems is no longer optional. It is essential.

Actionable Takeaways

• Pre-season screening and strength testing, alongside ongoing in-season monitoring, can help identify and manage risk

• Strength and neuromuscular training should be prioritized, including development of landing mechanics and force absorption

• Coaches can use warm-ups and training creatively to expose athletes to a wider range of movement patterns, which can improve engagement and reduce repetitive strain

• Avoiding early sport specialization where possible can support long-term performance and reduce injury risk

• Graft selection should consider individual factors such as age and injury history, with input from both the physio and orthopaedic surgeon

• Discussing additional surgical options, such as LET where appropriate, may improve outcomes in higher-risk athletes

• Education for both athletes and parents is key. Increasing awareness and training age can have a meaningful impact on long-term development and injury mitigation

For athletes or parents looking for more structured support, this is where individualized assessment and programming can make a meaningful difference: Book an Initial Assessment

Why Women Should Think Twice About Cold Plunges

Written by Evelyn Calado, MKin, CSCS, RKin

Cold plunges are everywhere right now. Scroll through social media, walk into any boutique gym, or listen to the latest biohacking podcast, and you're bound to hear someone praising the "recovery magic" of ice baths. But there's a problem: this recovery trend is not built for female physiology. And no one seems to be talking about it.

As a woman, especially one training hard and aiming to get stronger, faster, or more resilient, you need to know this: cold plunges can actually hinder your progress.

The Hype vs. The Science

The fitness industry often pushes one-size-fits-all solutions that are, in reality, designed around male physiology. Cold water immersion is no exception. The main argument for it is that it reduces inflammation and muscle soreness. But what’s rarely discussed is that blunting inflammation also blunts adaptation—the very thing you're working hard for in your training.

A key study published in The Journal of Physiology (2015) found that post-exercise cold water immersion significantly reduced long-term gains in muscle mass and strength by suppressing key anabolic signaling pathways. In simpler terms, jumping into a cold plunge after lifting can shut down the processes your body needs to get stronger.

The Female Factor: Why It’s Worse for Women

Dr. Stacy T. Sims, PhD, exercise physiologist and author of ROAR, explains that women already have a more robust anti-inflammatory response, largely due to estrogen. This is great for recovery in general—but it also means that adding more inflammation-suppressing strategies (like cold plunges) can tip the balance too far.

Here’s what that means:

• Estrogen helps buffer inflammation, so you don’t need the added suppression from cold water.

• Cold plunges inhibit mTOR signaling, a critical pathway for muscle protein synthesis. Since women already face challenges building and maintaining lean muscle due to fluctuating hormone levels—particularly during the high-progesterone phase of the menstrual cycle—this further suppresses adaptation.

• Women have a shorter post-exercise anabolic window. That means the timing and environment for recovery matter more. Cold exposure immediately post-training can close this window prematurely.

Heat, Not Cold, Supports Female Recovery

Dr. Sims recommends heat-based recovery tools for women, such as sauna use or hot baths. Heat increases blood flow, supports mitochondrial adaptations, and promotes muscle repair without blunting the natural signals for strength and hypertrophy.

Where cold shuts down your body’s growth processes, heat helps amplify them—especially beneficial for women looking to increase muscle mass, endurance, and overall athletic performance.

Let’s Talk About the Real Issue

This isn’t just a science debate. It’s a visibility problem. Right now, women are being told to do what’s trending without being informed of how it might hurt them. The fitness industry is ignoring female physiology. And it’s not okay.

If you're a woman who trains, lifts, runs, or just wants to be strong and healthy, you deserve better than a one-size-fits-all recovery strategy. You deserve recovery tools that actually work with your body, not against it.

So the next time someone tells you to jump into a cold plunge for recovery, remember that your physiology is different. And according to Dr. Stacy Sims and peer-reviewed research, cold plunges may be doing more harm than good for women.

Let’s change the conversation.

Why Leucine Matters Most for Muscle Growth and Recovery

Written by Evelyn Calado, MKin, CSCS, RKin

Why Leucine Matters Most for Muscle Growth and Recovery

Let’s talk about protein. More specifically, let’s talk about leucine.

Whether you're working to build strength, improve endurance, or maintain lean muscle as you age, your ability to recover and grow depends on one key trigger: muscle protein synthesis. And one amino acid plays the leading role in that process.

What Is Leucine and Why Does It Matter?

Leucine is one of the essential branched-chain amino acids (BCAAs). It acts as the “on switch” for muscle repair by activating a molecular pathway called mTOR, which tells your body to start rebuilding muscle tissue after training.

Without enough leucine, even a high-protein meal may not fully trigger muscle protein synthesis. This is why protein quality and amino acid composition matter just as much as hitting your total protein intake.

Why It’s Especially Important for Women

Women tend to have lower baseline rates of muscle protein synthesis compared to men, partly due to hormonal differences. For example, muscle breakdown increases during the luteal phase of the menstrual cycle, just before your period.

This is one area where Dr. Stacy Sims' work is helpful. In her book ROAR, she highlights the importance of choosing leucine-rich protein sources, especially after strength training or during high-hormone phases when recovery can be compromised.

The research supports this. For both performance and recovery, women benefit from being more deliberate with post-training protein intake.

What to aim for: At least 2.5 grams of leucine in your post-training meal or shake. This is typically the minimum needed to fully activate muscle repair pathways.

How Much Protein Do You Actually Need?

For active individuals, the research-supported recommendation is about 1.8 to 2.2 grams of protein per kilogram of body weight per day.

That protein should be spaced throughout the day across three to five meals, with roughly 20 to 40 grams of protein per meal depending on your size, goals, and training demands.

For both men and women, leucine still matters. If you don’t hit the leucine threshold in a meal, your body may not initiate the repair process efficiently, even if you meet your total daily intake.

What Plant-Based Athletes Need to Know

If you follow a plant-based or vegan diet, this is something to pay attention to. Many common plant-based protein sources like pea, rice, and hemp contain less leucine per serving than whey or other animal-based proteins.

Some vegan protein powders contain only 1 to 1.5 grams of leucine per serving. That is not enough to reach the 2.5-gram mark that research suggests is needed to trigger muscle protein synthesis effectively.

If your protein label doesn’t list leucine content, check the brand’s website or reach out to the company directly. You may need to supplement with isolated leucine powder or choose a blend that brings you closer to that threshold.

Simple Strategies That Work

• If you are not vegan, choose a high-quality whey isolate after training. Most servings contain around 2.7 grams of leucine.

• If you are vegan, look for blends that list leucine content and get close to 2.5 grams, or add free-form leucine to your post-workout shake.

• Do not rely on BCAAs alone. Always aim for a complete protein source after lifting or intense training.

• For women, be especially strategic about recovery nutrition during the luteal phase, when muscle breakdown is elevated.

The Bottom Line

Leucine is not just another buzzword. It is one of the most important amino acids for recovery and muscle growth.

Whether you eat animal protein, plant-based protein, or a combination of both, what matters most is that you are getting enough leucine to support the work you are putting in at the gym or on the field.

If you want to build muscle, maintain strength as you age, or support your training with purpose, start by paying attention to your post-workout protein. Total intake matters, but leucine matters even more.

Train. Play. Repeat.

Why Women Need a Different Approach to Post-Training Nutrition and Fasting

Written by Evelyn Calado, MKin, CSCS, RKin

When it comes to post-training nutrition and fasting, men and women are not the same. While much of the mainstream advice on nutrition and recovery is based on research conducted on men, emerging studies—led by experts like Dr. Stacy Sims—highlight the critical differences in how women should approach fueling and recovery. From the shorter post-training refueling window to the negative effects of fasted training, women need a tailored approach to optimize performance and long-term health.

Post-Training Nutrition: Why Women Need to Refuel Sooner

After training, the body enters a recovery phase where it repairs muscle tissue, replenishes glycogen stores, and shifts from a catabolic (breakdown) state to an anabolic (building) state. The timing of this recovery process differs significantly between men and women.

• Men have a longer window to refuel. Research suggests that men can maintain an elevated metabolic rate and glycogen resynthesis for up to three hours post-training. This gives them more flexibility in delaying post-workout meals.

• Women need to refuel within 30 to 90 minutes. Women’s metabolisms return to baseline much faster—typically within 60 to 90 minutes—meaning that delaying nutrition can hinder muscle repair and recovery.

Dr. Sims recommends that women prioritize at least 35 grams of high-quality protein within 45 minutes of finishing a training session. Pairing protein with carbohydrates helps replenish glycogen stores and prevent excessive muscle breakdown.

The Problem with Fasted Training for Women

Fasted training—exercising on an empty stomach—is often promoted as a tool for fat loss and metabolic efficiency. While this approach may work for some men, the physiological response in women is quite different, often leading to more harm than good.

1. Hormonal Disruptions

Women’s bodies are highly sensitive to energy availability. Training in a fasted state can disrupt key hormones like estrogen, progesterone, and cortisol, leading to negative effects such as irregular menstrual cycles, decreased thyroid function, and metabolic slowdowns.

2. Increased Stress Response

Morning cortisol levels are naturally high, and exercising without food further elevates stress hormones. This can lead to:

• Increased muscle breakdown

• Higher levels of fatigue

• Poor recovery over time

3. Impaired Performance and Recovery

Without adequate fuel, women often struggle to reach high training intensities. This means workouts may be less effective, leading to slower progress in strength and endurance. Additionally, prolonged fasted training can contribute to low energy availability (LEA), which has been linked to increased injury risk, poor immune function, and chronic fatigue.

What Women Should Do Instead

Instead of training fasted, Dr. Sims suggests women eat a small pre-training snack containing protein and carbohydrates, such as:

• A banana with a small amount of nut butter

• Greek yogurt with berries

• A protein shake with half a scoop of whey and some oats

Then, follow up with a proper post-training meal that includes a balance of protein, carbohydrates, and healthy fats to optimize recovery.

Final Thoughts

The takeaway? Women need to refuel sooner post-training and avoid fasted exercise to support optimal hormone function, performance, and long-term health. While men may have a more extended recovery window and can tolerate fasting with fewer consequences, women benefit from a more consistent intake of nutrients throughout the day.

By adjusting nutrition strategies to align with female physiology, women can maximize their training results, recover more efficiently, and sustain long-term health and performance.

For more insights, check out Dr. Stacy Sims' work, including her books and podcasts on women’s health and performance.