The menstrual phase is when your body is doing its most physically demanding work of the cycle, so the best things you can do are support it with the right food, gentle movement, warmth, and rest. This phase typically lasts three to seven days, and the drop in both estrogen and progesterone that triggers the shedding of your uterine lining also affects your energy, mood, and sleep. Here’s how to work with your body during this time instead of against it.
Why You Feel Different During Your Period
Your menstrual phase begins when both estrogen and progesterone fall to their lowest levels of your entire cycle. That hormonal drop is the direct signal for your uterine lining to break down and shed. But those same hormones influence far more than your uterus. Estrogen supports the production of serotonin, a brain chemical tied to mood and well-being. Research has shown that people with more severe premenstrual symptoms have significantly lower serotonin levels in the last ten days of their cycle, which can carry over into the first days of bleeding as a low, flat feeling.
At the same time, your core body temperature drops by 0.3°C to 0.7°C as progesterone falls. During the luteal phase (the two weeks before your period), progesterone kept your temperature elevated. Now that it’s declining, your body’s thermostat resets closer to baseline. This shift can actually benefit your sleep: REM sleep, which tends to be slightly reduced when progesterone is high, returns to normal patterns during the menstrual and early follicular phase. Many people find that once bleeding starts, they sleep more deeply than they did in the days leading up to their period.
Prioritize Iron-Rich Foods
You lose iron every time you bleed, and menstruation is the primary reason iron requirements for people who menstruate are so much higher than for those who don’t. Adult menstruating women need roughly 18.9 mg of dietary iron per day to meet the needs of 95% of the population, and menstruating teenagers need about 21.4 mg per day. Those numbers assume a typical Western diet where about 15% of the iron you eat actually gets absorbed.
The best food sources of easily absorbed iron include red meat, chicken, turkey, and fish. Plant-based sources like lentils, chickpeas, spinach, tofu, and fortified cereals also contribute, though your body absorbs that form of iron less efficiently. Pairing plant-based iron with vitamin C (citrus, bell peppers, tomatoes) significantly improves absorption. During your period specifically, making iron-rich meals a priority rather than an afterthought helps replenish what you’re actively losing.
Use Heat for Cramp Relief
If you reach for a heating pad when cramps hit, you’re using one of the most effective tools available. A large meta-analysis covering nearly 2,000 women found that heat therapy provides pain relief comparable to anti-inflammatory painkillers, both within 24 hours of use and over longer treatment periods. The difference is safety: heat therapy reduced the risk of side effects by about 70% compared to painkillers. A hot water bottle, adhesive heat patch, or warm bath all work.
For cramps that heat alone can’t manage, combining heat with an over-the-counter anti-inflammatory can be more effective than either approach on its own. The key with anti-inflammatories is timing. Taking one at the first sign of cramping, rather than waiting until pain peaks, helps block the inflammatory compounds your uterus releases to contract and shed its lining.
Move Gently, but Move
Exercise during your period is not only safe, it can reduce cramping. People who exercise regularly tend to report fewer painful cramps during menstruation overall. During the menstrual phase itself, your energy is genuinely lower, so this isn’t the time to push for personal records.
Walking, swimming, gentle yoga, and stretching are all good choices. Walking in particular has almost no downsides and tends to ease discomfort rather than worsen it. If you’re someone who normally does intense training, scaling back to about 60-70% of your usual effort for the first two or three days of your period is a reasonable approach. On the flip side, exercising too much or too intensely over time can cause missed periods or stop them entirely, a pattern more common in athletes and people who train hard on a regular schedule.
Stay Hydrated to Reduce Bloating
It sounds counterintuitive, but drinking more water helps reduce the bloating and fluid retention that often peaks in the first one to two days of your period. Hormonal shifts are the primary driver of water retention around menstruation, and your body is more likely to hold onto fluid when it senses dehydration.
Two practical strategies help the most. First, limit salty foods, which encourage your body to retain even more water. Second, consider magnesium, either through foods like pumpkin seeds, dark chocolate, and almonds, or through a supplement. Magnesium has evidence behind it for reducing premenstrual water retention, and it also plays a role in muscle relaxation, which may help with cramping.
Consider Omega-3 Supplements
If you deal with painful periods regularly, omega-3 fatty acids are worth trying. A meta-analysis of 12 studies found that daily supplementation of 300 to 1,800 mg of omega-3s over two to three months reduced both pain severity and the need for painkillers in women with menstrual cramps. Side effects were mild and uncommon. The supplements used in these studies were the long-chain type found in fish oil (EPA and DHA), not the shorter-chain type from flaxseed. You won’t notice a difference during your very first cycle of taking them. The benefits build over two to three months of consistent daily use.
Choose the Right Menstrual Products
How often you need to change your menstrual product depends on what you’re using and how heavy your flow is. Tampons should be changed every four to eight hours. Menstrual cups can safely stay in for up to 12 hours before emptying, which makes them a practical choice for overnight use or long days. Pads have no strict time limit tied to infection risk but should be changed when they feel wet or uncomfortable, typically every three to six hours on heavier days.
If you’re soaking through a pad or tampon every hour for more than two consecutive hours, that’s beyond the range of normal heavy flow. Clinically, this is considered menorrhagia, and it’s worth a conversation with a healthcare provider, especially if it happens cycle after cycle. That level of blood loss can deplete your iron stores quickly and lead to anemia.
Give Yourself Permission to Rest
The first two days of your period are typically when bleeding, cramping, and fatigue are at their worst. Your hormones are at rock bottom, your body is doing real physical work, and your energy reflects that. This is a genuinely low-energy phase of your cycle, not a motivational failure.
If your schedule allows it, building in lighter days at the start of your period pays off. That might mean shorter workouts, earlier bedtimes, or saying no to optional obligations. The temperature drop from declining progesterone means your body is better set up for sleep than it was in the luteal phase, so take advantage of that. Cool your bedroom, keep a consistent bedtime, and let your body do what it’s already primed to do: recover.