Body Temperature and Pulse

One of the tests you can use at home is a very simple one that I recommend to many of my clients and use myself. It can help check for patterns of ovulation, optimal progesterone production, and overall metabolic rate. This is done by testing your body temperature and pulse on a day-to-day basis. As we saw earlier, body temperature shifts throughout the month depending on whether you are in your follicular phase or your luteal phase. Because progesterone is a pro-thyroid, pro-metabolic hormone, you’ll often see an increase in body temperature after ovulation. If you’re unsure whether you’re ovulating, you can test your body temperature daily through your cycle. You’ll see a shift in the second half of the cycle—normally about a 0.4–0.5°C increase in body temperature. If progesterone production is robust, it will stay high for the whole second half of the cycle until hormones drop and menstruation begins. If your temperature falls in the second half of the cycle, it can indicate that progesterone production isn’t strong enough. This is great if you’re struggling to know whether you’re ovulating or producing enough progesterone. I usually have clients track a couple of cycles to see if they observe a clear shift in the second half. You may have done this before if you were trying to get pregnant—tracking basal body temperature is often used for that—but you can use it even when you’re not trying to conceive to understand your hormonal health. Body temperature is also a good indicator of overall metabolic and thyroid health. The thyroid is the body’s internal thermostat. If it’s working well, we feel generally warm—hands and feet are warm, the tip of the nose is warm, and we’re not the person freezing in an office while everyone else is comfortable in a T-shirt. That warmth is a sign of good metabolic health. There was a physician named Broda Barnes, a thyroid specialist, who used this test to identify thyroid dysfunction. He noted that if your body temperature was consistently below 36.4–36.5°C in the mornings upon waking, this could be a sign that your thyroid is suboptimal. Think of it as your thermostat being turned down—everything slows and cools down. Testing your body temperature throughout the day gives an idea of your baseline metabolic rate and how it changes. How to Test Body Temperature First thing in the morning, take your temperature at complete rest—before you get out of bed. Don’t get up to use the bathroom and then come back. As soon as you wake up, ideally at the same time each day, have a basal thermometer by your bedside, place it in your mouth, let it warm up for a bit, and then press the button to take your reading. Track it throughout the month. Ideally, in the first half of your cycle—the follicular phase—you’ll see temperatures around 36.4°C or higher upon waking. In the second half of your cycle, after ovulation, progesterone will raise it higher, around 36.8–36.9°C. You can also take your temperature at other times of the day to see how your body reacts to food. Sometimes clients have an optimal temperature in the morning, but when they eat breakfast, the temperature drops. That can indicate that the morning temperature was high due to adrenaline or cortisol—stress hormones from things like blood sugar dips overnight—and eating reduces stress hormones, revealing your true energy level. Ideally, after eating, body temperature should rise slightly because the thermogenic effect of food boosts metabolic activity. If it doesn’t, or if it drops, it may indicate high stress hormones, poor glucose metabolism, or low thyroid function. You can take your temperature three times a day if you like—first thing in the morning, after breakfast, and again in the afternoon. Temperature is usually highest after lunch and then begins to fall before bedtime, following the same rhythm as cortisol and sunlight. Pulse Tracking You can also check your pulse. This is optional but can give additional insight. Think of the pulse as part of the same thermostat—when the body is working efficiently, the pulse is warm and strong. An optimal pulse is between 65 and 85 beats per minute. Many athletic people have much lower pulses, often around 45, which is a sign of fitness, but it can also mean the body is adapting to constant high output by slowing things down. So, temperature and pulse together show how efficiently your internal engine is running. These aren’t meant to create stress or become another task to fixate on—they’re just tools to help you understand how your body is doing day to day. It’s data, not judgment. It simply gives you feedback about how your hormones, metabolism, and stress levels are interacting.