How does contraception choice impact training?
In the previous two blogs, Coach Denise has looked at the female monthly cycle in terms of hormone production and how these changes can then impact the individual throughout the month. These changes and impacts are relevant to a female athlete with no external hormone input, but what happens when an athlete uses hormone-based contraception? In this blog Coach Denise looks at how externally administered hormones can impact a female athlete.
With studies indicating that around 50% of elite female athletes use some form of hormonal contraception, this is clearly an area that has an impact on many women, whatever level of training and competing they are at. Understanding the menstrual cycle and the hormonal changes and impacts is a good starting point but what effect does using hormone-based contraception have on the individual.
To answer this question the starting point is to look at what hormone-based contraceptive choices there are. The following is a list of the main options:
Combined Pills – contain oestrogen and progestogen
Mini Pills – contain progestogen only
Patches - contain oestrogen and progestogen
Implants and injections – contain progestogen
IUS -contain progestogen
Vaginal ring - contains oestrogen and progestogen
Note that IUD’s which release copper, are not hormone-based, and so are not included in this discussion.
The main role of a hormone-based contraceptive is to suppress the naturally occurring hormones of oestrogen and progesterone, to disrupt the monthly cycle and so reduce the chance of pregnancy. The hormones within the pills or device, oestrogen and progestogen, replace the naturally occurring hormones. In addition to preventing pregnancy, there may be other reasons for using a particular contraceptive method, such as reducing premenstrual symptoms or bleeding. Whatever the reason for using a particular type of contraception, the effect on the body is the same.
If a pill or patch contraceptive is used, the hormones are present in the body at a constant level for 21 days. There is then a 7 day time period when no hormone is ingested, either from a break in taking the pill or taking a placebo pill.
If implants, injections, IUS or a vaginal ring are used then the level of hormone present within the body is constant with no monthly cycle variations.
The effect of this hormone change on the woman experiencing it can vary widely. Some women report more regular periods, while others stop having periods altogether.
The second blog of this series considered the possible impact of hormone changes through the monthly cycle. While this varies a lot across individuals, there is clearly an obvious question here. If a female athlete is using a hormone-based contraceptive, and the hormone levels are flat across the cycle, what impact does this have on training?
In fact, the research in this area is not extensive, with many of the studies having small sample groups or non-controlled data. Most of the studies to date have looked at the impact of the contraceptive pill on athletes, rather than any other type of contraceptive. A meta-study in 2020 looked at 42 existing studies covering 590 participants. In this analysis, only 17% of the studies analysed were considered to be of high quality, with 83% categorised as moderate or poor quality. What this means is that any conclusions from the study should be considered carefully, and not necessarily drive any changes in behaviour.
What the study did find was that in female athletes using an oral contraceptive, when compared with those using no contraceptive, there was a very slightly inferior performance in the resistance training studied. However, the authors highlight that this effect is very slight and there is still a lot of variation across women from a range of other sources. There is certainly not enough evidence to suggest that female athletes should stop using oral contraceptives, especially if there are good medical, or lifestyle, reasons for using them.
Since the hormone levels are level across most, if not all, the monthly cycle, does it still make sense for a female athlete to track where they are in the cycle? The answer to this question is yes. There are many factors which can influence performance and understanding them and reacting to them can always help to improve the planning of training and the outcome of that training.
One complication is that many women using hormone-based contraceptives stop having periods, which means that a major way to determine just where they are in their cycle is not available. It may be possible to use body temperature to determine the cycle position, but this is not fully reliable and is a stronger effect for some women than others.
In all cases, the advice from one of the authors in the meta-study analysis, Dr Kirsty Elliot Sale, is that it makes sense to track how sessions go, how the athlete is feeling and what their mood and attitude to training is across a 3-6 month time period. Using this information, the coach and athlete can look for patterns, which may be cyclical in nature, or may not.
There are symptoms that may not appear to be menstrual cycle-related, but actually could be a result of hormonal changes. Anecdotally, some athletes have identified increased trips and falls at the same point in their menstrual cycle, ongoing injuries being worse at set times in their cycle, lack of motivation or other intangible subjective “feelings”. Often, these may seem unrelated, but it is only after considering their monthly cycle do they make the connection.
Does this mean women are more likely to trip, get more injured or feel pain more, or have less motivation because of their menstrual cycle? The data is not clear, and the answer is probably not to a measurable extent because of the number of other variables. However, if an athlete knows their own body well, and knows what to look for in terms of ‘tells’, they can choose to make different decisions around their training. Perhaps substituting a run on the road rather than the trails, or maybe taking it a little easier in a session. Certainly, if there is a reason for feeling ‘off’ in whatever way then it makes sense to be kinder on yourself as there is a reason for the way you feel.
If no clear pattern exists for an athlete tracking her cycle, then continued tracking is less important, after all, there is enough to be doing already. If the cycle does appear to be affecting performance, then this can be factored into the training plan.
In summary, understanding just what is happening in your body, whatever the cause, is always good. It can help drive a conversation between the coach and the athlete, inform the training plan and help the athlete take control of their own training and results.
Denise has been coaching triathletes since 2019 as a coach at her local triathlon club in West Lothian. Between 2019 and 2022, Denise was the Head coach in the club, working with a team of coaches to support and develop triathletes with a wide range of capabilities, completing her BTF Triathlon Level 2 coaching qualification in 2021.
Denise joined Tri Training Harder as a coach in 2021, building on the qualifications through the experience and knowledge passed on by the coaching team.
In 2019 Denise set up and continues to run her own Jog Scotland running group, a mixed ability group of runners who meet weekly. This delivers on her passion for helping people to do much more than they think they can.
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