85: THIS Is What Birth Control Is Doing To Your Body…
THIS Is What Birth Control Is Doing To Your Body (And Your Gains)
Naturopathic doctor Lara Briden reveals how hormonal birth control affects muscle growth, metabolism, and insulin sensitivity, plus what you need to know about cycle syncing and training optimization.
Let's be real, how often do you actually think about how hormonal birth control is affecting your body? Most women take it without fully understanding the ripple effects it has on everything from muscle growth to metabolism to gut health.
If you're lifting weights, trying to build muscle, or working on body composition goals, this conversation is essential. In this episode, Tara sits down with Lara Briden, naturopathic doctor and author of Period Repair Manual and Hormone Repair Manual, to dig into the technical side of hormonal birth control and what it's really doing to your body.
This isn't about judgment or telling you what to do with your reproductive choices. It's about giving you the information you need to make informed decisions about your health and understand why your fitness progress might be stalling.
How Birth Control Affects Muscle Growth (The Study Everyone's Talking About)
Let's start with the elephant in the room: a recent study showed that women on hormonal birth control experienced significantly less muscle growth compared to women with natural cycles, even when following the same training program.
Why? Because synthetic hormones interfere with your body's natural hormone production. When you're on the pill or other hormonal contraceptives, you're not producing the same levels of testosterone and growth hormone that support muscle protein synthesis. Essentially, you're training with one hand tied behind your back.
This doesn't mean you can't build muscle on birth control, plenty of women do. But it does mean you're working against some significant metabolic disadvantages. And if you've been wondering why your strength gains have plateaued or why building muscle feels harder than it should, this might be part of the answer.
Lara explains that synthetic hormones don't just suppress ovulation, they suppress your entire hormonal system. And your hormones play a crucial role in everything from how you build muscle to how you metabolize food to how you recover from workouts.
The Metabolic Side Effects No One Talks About
Beyond muscle growth, hormonal birth control has some serious implications for your metabolic health that rarely get discussed in doctor's offices.
Insulin resistance. Synthetic hormones can interfere with insulin sensitivity, making it harder for your body to regulate blood sugar effectively. This means you're more likely to store fat, experience energy crashes, and struggle with cravings, even if you're eating well and training consistently.
Gut health disruption. Hormonal contraceptives can alter your gut microbiome and increase intestinal permeability (aka leaky gut). Since your gut health is intimately connected to your immune system, inflammation levels, and even your mood, this is a bigger deal than most people realize.
Nutrient depletion. Birth control pills are notorious for depleting key nutrients like B vitamins, magnesium, zinc, and selenium. These nutrients are essential for energy production, muscle recovery, thyroid function, and hormonal balance. So even if you're eating a perfect diet, you might be running on empty.
Inflammation. Synthetic hormones can increase systemic inflammation in the body, which not only makes it harder to recover from workouts but also increases your risk for chronic health conditions down the line.
The bottom line? Hormonal birth control isn't just preventing pregnancy, it's fundamentally changing how your body functions. And for women who are serious about their fitness and health, these changes matter.
Non-Hormonal Alternatives: What Are Your Options?
So what if you want effective birth control without the metabolic side effects? Lara breaks down the non-hormonal options that are worth considering.
Copper IUD. This is the most effective non-hormonal contraceptive option available. It works by creating an environment that's hostile to sperm (copper is toxic to sperm), and it lasts for up to 10 years. The downside? Some women experience heavier periods or cramping, especially in the first few months. But for many women, this is a worthwhile trade-off to maintain their natural hormone cycles.
Barrier methods. Condoms, diaphragms, and cervical caps are all non-hormonal options that give you control over contraception without systemic effects on your body. They require more planning and aren't quite as effective as IUDs, but they're worth considering.
Fertility awareness methods. When done correctly (and Lara emphasizes the "correctly" part), tracking your cycle and understanding your fertile window can be an effective form of contraception. This requires education, consistency, and a willingness to abstain or use backup methods during your fertile window.
The conversation also touches on the hormonal IUD, which many women think of as "low dose" or "better" than the pill. While it does deliver hormones locally rather than systemically, Lara explains that it still suppresses ovarian function and can have similar effects on your natural cycle.
Understanding Your Cycle and Training Around It
One of the most fascinating parts of this conversation is the discussion about body literacy, actually understanding what's happening in your body throughout your menstrual cycle and using that information to optimize your training.
When you have a natural cycle (meaning you're not on hormonal birth control), your hormones fluctuate predictably throughout the month. And these fluctuations affect everything from your energy levels to your strength to your recovery capacity.
The follicular phase (roughly days 1-14): Your estrogen is rising, and this is when many women feel strongest, most energetic, and most capable of handling heavy training. This is a great time to push intensity, add volume, and go after PRs.
Ovulation (around day 14): This is when testosterone peaks alongside estrogen. Many women report feeling their absolute strongest during this narrow window. Take advantage of it.
The luteal phase (roughly days 15-28): Progesterone rises and energy often dips. This is a good time to focus on technique work, deload phases, or slightly lower intensity training. Your body is working harder just to maintain baseline function during this phase, honor that.
Menstruation (days 1-5): The beginning of your cycle. Some women feel great training during their period, others need to dial it back. Listen to your body and adjust accordingly.
Lara and Tara discuss the concept of cycle syncing, adjusting your training, nutrition, and lifestyle based on where you are in your cycle. While you don't need to completely overhaul your program every week, being aware of these patterns can help you train smarter and avoid pushing too hard when your body needs rest.
The Reality Check on Cycle Syncing and Metabolism
Now, before you get carried away with cycle syncing protocols, here's the reality check: the metabolic differences between phases of your cycle are relatively small. We're talking about a 5-10% variation in metabolic rate at most.
The conversation emphasizes that you don't need to dramatically change your calorie intake or completely restructure your training based on your cycle. But being aware of the patterns can help you be more strategic and compassionate with yourself.
For example, if you know you typically feel lower energy in the week before your period, you can plan for that. Maybe that's not the week to start a new program or add extra cardio. Maybe that's the week to prioritize sleep, manage stress, and maintain rather than push.
The goal isn't perfection, it's awareness. And when you're on hormonal birth control, you lose access to these natural rhythms. Your hormone levels stay flat throughout the month, which means you miss out on the natural performance peaks and also the built-in recovery signals your body provides.
Transitioning Off Birth Control: What to Expect
If you're considering coming off hormonal birth control, Lara shares what to expect and how to support your body through the transition.
First, understand that it can take several months for your natural cycle to return and stabilize. For some women, their period comes back immediately. For others, it takes 6-12 months or longer. This is called post-birth control syndrome, and it's a real phenomenon.
Support your body during the transition:
Focus on nutrient-dense foods to replenish depleted vitamins and minerals
Prioritize protein and healthy fats to support hormone production
Manage stress, as high cortisol can interfere with cycle restoration
Be patient with your body as it recalibrates
What you might experience:
Irregular periods for the first few months
Changes in skin (acne is common as your hormones rebalance)
Mood fluctuations as your natural hormone cycles return
Changes in energy levels and libido
The good news? Many women report feeling significantly better once they're off hormonal birth control. Clearer thinking, better mood stability, improved libido, easier muscle building, and better body composition changes are all commonly reported benefits.
Metabolic Flexibility and Long-Term Health
The episode closes with a discussion about metabolic flexibility, your body's ability to efficiently switch between burning carbs and burning fat for fuel. This is a crucial component of metabolic health that often gets overlooked in fitness conversations.
When your hormones are balanced and your body is functioning optimally, you should be able to fast for a few hours without getting hangry, exercise without needing to immediately refuel, and maintain stable energy throughout the day. If you can't do these things, it's a sign that your metabolic flexibility needs work.
Hormonal birth control can interfere with metabolic flexibility by affecting insulin sensitivity and how your body partitions nutrients. This is yet another reason why optimizing your hormonal health matters for your fitness goals.
The Bottom Line
This isn't about demonizing birth control or telling you what choices to make with your body. It's about giving you the full picture so you can make informed decisions that align with your health and fitness goals.
If you're on hormonal birth control and happy with it, that's completely valid. But if you're struggling with muscle growth, dealing with metabolic issues, or just feeling "off" in ways you can't quite explain, your birth control might be a bigger factor than you realize.
What's your experience with birth control and fitness? Share your story with us on Instagram @broads.podcast, we know this is a topic that affects so many women, and your experience matters.
