Does birth control decrease strength and performance?
Gone are the days when women are treated like small men in the health and fitness industry! I will be the first to say that we have come a long way, but we still have a long journey ahead. Many studies that coaches quote to share evidence-based information are conducted on men, and we only have a little data on women. This is something that I am hopeful will begin to change over the coming years. Nonetheless, coaches are becoming more aware of women’s different needs compared to their male counterparts, raising important questions such as whether contraception decreases performance or impairs strength gains?
This blog post aims to answer that question.
NOTE: This is not medical advice. The use of contraception is a woman’s right, and this information is not intended to be used as medical advice. Any decisions around contraception should be carefully considered by a qualified health care professional.
Types of contraception
Before we jump into exploring if contraception impairs performance, let’s unpack some of the types of hormonal contraception:
- The contraceptive pill
- Intrauterine devices (caveat: the copper IUD does not contain hormones)
- Depot injections
- The Implanon
The oral contraceptive pill
The contraceptive pill is a medication taken by women to prevent pregnancy. There are two types of oral contraception: the combined pill, which contains oestrogen and progesterone, and the mini-pill, which contains progesterone only. The combined pill is the most common type of contraceptive pill. It works by preventing ovulation (the release of an egg from the ovary), thickening the mucus in the cervix (the neck of the womb), and thinning the womb’s lining. This makes it difficult for sperm to travel up through the cervix and makes it less likely that an embryo will be able to implant itself in the womb. The contraceptive pill is not 100% effective, but it is one of the most reliable forms of contraception. It is important to remember that the pill does not protect against sexually transmitted infections (STIs). If you think you might be at risk of contracting an STI, you should use a condom and take the pill.
Intrauterine Devices (IUD’s)
An IUD is a small, T-shaped device that is inserted into the uterus to prevent pregnancy. IUDs are one of the most effective forms of birth control, with a failure rate of less than 1%. There are two types of IUDs: hormonal and copper. Hormonal IUDs release a small amount of progestin, which thickens the cervical mucus and prevents sperm from reaching the egg. Copper IUD’s contain wire coiled around the device, producing an inflammatory reaction that is toxic to sperm and eggs, therefore, preventing pregnancy. Both of these options do not stop ovulation like other forms of hormonal contraception, so a woman can still track her cycle if she wishes to. The insertion process can be uncomfortable, but it is typically over within a few minutes. Some women experience side effects such as cramping, bleeding, or spotting in the first few months after insertion, but these typically resolve independently.
Depot contraception shot, also known as the contraceptive injection, is a hormonal contraception method administered by a healthcare provider every three months. The active ingredient in the depot contraception shot is progestin, which prevents pregnancy by thickening the cervical mucus and thinning the endometrium. Depot contraception shots are highly effective, with a failure rate of less than 1%. However, the depot injection has been linked with a decrease in bone mineral density which can increase the likelihood of stress fractures and osteoarthritis.
Implanon is a selective estrogen receptor modulator (SERM) and progesterone receptor agonist used as a birth control method. It is a small, flexible rod inserted under the upper arm’s skin and releases the hormones etonogestrel and progesterone. Implanon works by inhibiting ovulation and thickening the mucus in the cervix, making it difficult for sperm to reach the egg. It also alters the lining of the uterus, making it less hospitable for implantation. Implanon is more than 99% effective at preventing pregnancy, making it one of the most reliable birth control methods. It is also very convenient, as it only needs to be taken daily or replaced every few months like other methods.
Birth control and your menstrual cycle
The majority of birth control works by making the body believe it is pregnant in one way or another. This prevents ovulation which means that the woman does not experience a ‘real’ bleed that follows ovulation when an egg has not been fertilised. The bleed many women have while taking hormonal birth control is known as a ‘withdrawal’ bleed. This isn’t the same as a period, and it does not follow the same hormonal fluctuations that a woman experiences with a natural cycle. This is important because it helps to understand why women may experience a decrease in strength and performance when taking hormonal birth control.
Does hormonal contraception impact strength and performance?
A recent meta-analysis looked to answer this question. A meta-analysis is a statistical technique that combines the results of multiple scientific studies. A meta-analysis aims to identify patterns and trends in the data and assess the strength of associations between variables. Meta-analyses are particularly useful in fields with a large amount of research and where individual studies may be small or have conflicting results.
The study looked at 42 different papers and graphed the results of the studies that favoured increased performance in naturally menstruating women compared to women on hormonal birth control. The majority of the studies favoured increased performance and strength in naturally menstruating women.
However, the results were almost non-significant.
The study concluded with the following: “OCP use might result in slightly inferior exercise performance on average when compared to naturally menstruating women, although any group-level effect is most likely to be trivial. Practically, as effects tended to be trivial and variable across studies, the current evidence does not warrant general guidance on OCP use compared with non-use. Therefore, when exercise performance is a priority, an individualised approach might be more appropriate. The analysis also indicated that exercise performance was consistent across the OCP cycle.”
What does this mean practically for you?
Each woman responds differently to contraception. For some women, it manages symptoms that are debilitating without contraception. Pain and performance generally don’t go hand in hand, so you can see that for some women, hormonal birth control helps strength and performance. For others, there may be a slight decrease in performance and strength when taking hormonal birth control. As with most things, individual context is essential to consider. However, you can continue performing at a high standard when taking hormonal birth control.
Yours in Health,
Head of Nutrition at CMC and Registered Nurse.