"This week, I’ve been feeling heavy. Not just bloated. Mentally and physically off. Two days into my period and I already feel slower, foggier, and a bit over it." If you’re in the same space, here’s what’s actually happening inside your body and brain when your cycle hits. This isn't just a hormone shift. It’s feedback.
What’s Actually Happening in Each Phase of Your Cycle
Your menstrual cycle affects more than just your mood. It influences how you train, how you sleep, how you digest food, how you recover, and how your brain handles effort. Two hormones are running the show: estrogen and progesterone. When you understand what they’re doing, everything from your mood to your motivation to your training performance starts to make a whole lot more sense.
Estrogen is the hormone that rises in the first half of your cycle (follicular and ovulation phases). It’s associated with:
- Energy and motivation: Helps regulate dopamine and serotonin, which affects mood, focus, and drive
- Muscle strength and coordination: Supports neuromuscular efficiency, making you feel stronger and more stable during training
- Pain tolerance: Can slightly increase around ovulation, making high-intensity training feel more doable
- Insulin sensitivity: Helps your body use carbs more efficiently, which is why your energy often feels better early in your cycle
- Recovery and adaptation: Supports muscle repair and bone health
Progesterone rises in the second half of your cycle (luteal phase) and is more about maintenance, slowing things down and preparing your body for rest or potential pregnancy. It’s linked to:
- Increased body temperature: Makes you feel hotter and can slightly impair sleep
- Water retention: Contributes to bloating and puffiness
- Reduced insulin sensitivity: You may crave more carbs and feel more tired or foggy
- Slower digestion: Can make you feel heavy, constipated, or sluggish
- Calming effects: In small amounts, it can feel grounding, but if you’re sensitive, it can also make you feel dull or withdrawn
- Lower training capacity: You may fatigue faster and need more recovery between sessions
During the menstrual phase (roughly Days 1 to 5), estrogen and progesterone are both low. Energy is usually down, recovery slows, and strength output often drops. This is a good time to reduce intensity and focus on movement that supports mental clarity. In the follicular phase(Days 6 to 14), estrogen begins to rise and energy levels improve. Coordination, focus, and performance tend to increase, making it easier to handle harder training sessions. Around ovulation (around Day 14), estrogen peaks. This is your most powerful window with higher pain tolerance, stronger lifts, and a sharper mind. It's often the best time to push performance. The luteal phase (Days 15 to 28) follows, with progesterone rising and estrogen declining. Core body temperature goes up, sleep can become disrupted, and bloating or mood changes are common. Training may feel harder during this time, but it remains effective. This is where structure matters most. You may need to adjust effort, support recovery, and stay consistent without relying on motivation alone.
Why You Feel Bigger or More Bloated
Bloating around your period is driven by hormone shifts. Progesterone causes fluid retention and slows digestion. Estrogen affects serotonin which can change your appetite and increase cravings for carbs. Carbs store more water than protein or fat, so your weight can spike even if your calorie intake hasn't. You didn’t gain fat. You’re holding water and slowing digestion. That’s it.
Your Brain Feels Flat Because It Is
Low estrogen means lower dopamine. Dopamine drives motivation, energy and focus. That’s why you’re scrolling more, snacking more and thinking less clearly. This isn’t you slacking. It’s a real shift in brain chemistry. But you’re still responsible for how you respond to it. Here’s what helps when you’re foggy, low, and tempted to tap out:
- Cut screen time to reduce dopamine burnout and overstimulation
- Walk after meals to regulate blood sugar, digestion, and mood
- Keep caffeine low and water high.
- Eat balanced meals on a schedule. Don’t skip meals and then blame your cravings
- Prioritise protein and healthy fats to keep your energy and mood more stable
- Take a magnesium supplement before bed to help with sleep, cramps, and mood swings
- Stick to a sleep window even if your energy is low, getting out of rhythm makes it worse
- Lift something, strength training can reduce PMS symptoms and boost mood, even if it's light
- Limit alcohol. It worsens inflammation, bloating, and disrupts already fragile sleep
- Journal or offload stress. Mental clutter increases the sense of overwhelm
Should You Train Through It?
You can. Most do. If energy is low, focus on movement over performance. Still train. Walks. Bodyweight. Stretching. If you’re feeling fine, train as normal but don’t panic if you feel weaker. Your body is working through repair. It’s a cycle, not a setback. Not feeling fine? You’re not alone. We have clients who are bedridden or relying on strong painkillers just to cope. How do they handle it? They rest. They readjust. They shift the weight of their workouts across the month, giving themselves space when their period hits but still hitting the same total number of sessions as someone who trains straight through. That might look like this: Week 1 (period week) = 3 workouts, Week 2 = 5 workouts, Week 3 = 6 workouts, Week 4 = 6 workouts. Nothing skipped. Just redistributed.
Audit This Week (Honestly)
Ask yourself:
- Am I using this phase as permission to spiral with food or skip basics?
- Am I ignoring water, fibre and sleep and calling it “hormones”?
- Am I still showing up with discipline, or letting comfort win?
There is nothing wrong with needing rest. But there is a big difference between rest and avoidance. One helps you recover. The other keeps you stuck.
Final Note
Your body is not betraying you. It’s communicating. It’s giving you data. Learn the signals and adjust your inputs. That’s ownership. Bloat doesn’t mean you’ve failed. Cravings aren’t proof you’re broken. And a sluggish brain isn’t a reason to give up on yourself for a week. Take care of yourself without letting yourself off the hook. Period.