CYCLE TRACKING: GET TO KNOW YOUR TEMPERATURE
WHAT IS CYCLE TRACKING?
Cycle tracking consists of measuring your basal body temperature (BBT) each morning. Your BBT is the lowest temperature your body reaches while you sleep.
When you understand what is happening in your body at a physiological level you can determine if and when something is abnormal so you can take action.
HOW DOES IT WORK?
Your menstrual cycle has 2 main phases: the follicular phase and the luteal phase. Your temperature will vary based on which stage of your menstrual cycle you are in. Your BBT will be slightly lower during the follicular phase. Then it will raise slightly during the luteal phase due to the thermogenic effect of progesterone (so as progesterone falls later in the luteal phase so will your temperature).
FOLLICULAR PHASE
- The follicular phase is the first half of your cycle and is typically 14 days long. Its starts on day 1 of your cycle (the first day of your period), and ends at ovulation.
- This phase is governed mainly by estrogen, FSH and LH.
- Follicular Phase Temperature: typically ranges from 36.11 – 36.50°C
LUTEAL PHASE
- The luteal phase is the second half of your cycle. It begins at ovulation and ends with the start of your period (where you then enter the follicular phase again).
- This phase is also typically 14 days long, and is governed mainly by progesterone.
- Luteal Phase Temperature: typically ranges from 36.50 – 36.83°C
The most noticeable change is the transition from the follicular phase to luteal phase, marked by a temperature shift – a spike in your BBT (basal body temperature). The last day of a low temperature BEFORE the temperature spike is the day of your ovulation.
How do you know if you’ve had a true temperature shift? Temperature shifts vary drastically between women. Some of us have larger more obvious shifts, while other’s shifts are more subtle. You will be able to spot your shift pattern after a few months of charting.
Here are some things to look for in a (large) shift:
- Your temperature on the day of your temperature shift will be at least 0.11°C higher than the previous day and 0.05°C higher than each of the previous 6 days.
- Your temperature must remain at least 0.05°C above those previous 6 days for 3 days in a row.
This is an example of what your cycle tracking chart may look like. This one is from the Kindara App (its in °F but the pattern will look the same in °C).
WHY SHOULD I TRACK MY CYCLE?
After a few months of tracking you will see a pattern in your BBT (basal body temperature). This pattern will show when (and if) you are ovulating, which will predict your fertile days.
Depending on your goal, knowing when you will ovulate can help you avoid pregnancy or help optimize your attempts at getting pregnant.
The pattern will also show how your hormones are functioning together and alert you to any imbalances – such as an imbalance of progesterone and estrogen.
WHAT ELSE SHOULD I BE TRACKING?
You can also track your physical and emotional symptoms, your cervical fluid, the position of your cervix, and anything else you notice varies with your cycle – such as acne or headaches. This more advanced cycle tracking is called the Fertility Awareness Method (FAM). I will be posting more about this over the next few weeks.
For now, learn how to start tracking your cycle!
HOW TO GET STARTED
1. Download a fertility awareness app. My favourite (and free) app is Kindara.
2. Buy a basal body thermometer (around $10).
- You will be measuring your basal body temperature (BBT), which is the lowest temperature your body reaches.
- Ensure you are using a basal body thermometer (not a regular thermometer). We need it to display 2 decimal places (ex. 36.40°C). These are often referred to as ‘ovulation thermometers’ and may be located alongside more basic thermometers or in the family planning section of stores.
3. Start tracking!
Use these rules for accurate cycle tracking:
- Take your temperature as soon as you wake up in the morning (before you start to move around).
- Take your temperature at the same time each morning (within a 30 minute window).
- Take your temperature after a minimum of 3 hours of consistent sleep.
- Make a note in the app of anything that may change your temperature:
- A poor nights sleep, feeling unwell, consuming alcohol the night before.
- After 3 or more months of tracking you should have a good picture of your menstrual cycle pattern, including predictions of the day you will ovulate and the days/length of your period.
If you want to learn more about cycle tracking and how to optimize your hormonal health naturally feel free to contact me here.
Happy tracking!
Resources:
Miller, C. (2014 Apr). When Should I Mark a Temperature Shift in the App https://www.kindara.com/blog/when-should-i-mark-a-temperature-shift-in-the-app
