Hormones & ACL Knee Injuries: Are they connected?
- drjimk
- Aug 1, 2023
- 4 min read
Females have much more naturally occurring of the hormone estrogen. Essential to bone growth, this hormone (along with others) fluctuates during the menstrual cycle, which affects the strength and stability of the tendons and ligaments of the knee and other joints. Estrogen levels specifically are their highest during the end of the follicular phase of the menstrual cycle, which appears to coincide with the time when the highest rate of ACL knee injuries occur. A recent injury incident study found that injury rates in athletes occurred over twice as often during the late follicular phase as compared to other phases of the menstrual cycle. Findings such as this have prompted the need for and importance of ongoing scientific investigation.
This topic of the female menstrual cycle and periods have often been viewed as taboo, despite the fact that roughly half of the population will experience them. Since it is known that symptoms associated with the menstrual cycles can affect performance, there is a need to start encouraging the conversation between female athletes, parents, coaches, and teammates to better normalize the topic.
At the elite levels of soccer, some coaches and their staff are now designing individualized plans for athletes around the phases of their menstrual cycle as this may help to control a player's susceptibility to soft tissue injuries, such as the increasingly common anterior cruciate ligament (ACL) injuries of the knee. Currently, there are apps available such as the FitrWoman app (https://www.fitrwoman.com) by the sports science company, Orreco that help with these individualized plans. This app allows one to input information about their menstrual health and related symptoms, which can then be logged and monitored. With proper consent, coaches may also access this information and tailor their training programs. Tracking the menstrual cycle allows for the identification of specific cycle characteristics (e.g. cycle length), allows the athlete to better prepare, as well as to seek help from a medical professional if their cycle becomes elongated or stops altogether.
As part of Orreco’s work with the USA and England (national teams), they have encouraged players to include a daily smoothie in their diet regimen that consists of different ingredients depending on their current menstrual cycle phase.
Below are general training and nutrition basics proposed for the different menstrual phases:
- A normal cycle is generally in the 21 to 35 days range and the average cycle is 28 days.
- It is noted that tracking is not something that would be effective for those on hormonal birth control, as their hormones are regulated by the birth control pills.
Phase 1 (Menstrual Phase) – Typically the first 3-8 days of the cycle:
This phase starts with the first day of bleeding and ends with the last day of bleeding, and may include:
Increasing adaption to strength & high intensity training
Reduced neuromuscular control
Increased iron requirement
Athletes may need to perform exercises to treat and manage symptoms, since this is the phase when they are more likely to experience them. However, high-intensity strength and conditioning workouts are reported to be better tolerated in this phase. Additionally, in this phase players need plenty of antioxidants and anti-inflammatory foods, as well as carbohydrates, so adding some berries, oats, and flaxseed to a smoothie can be a good idea. As far as meals go, include fibrous carbohydrates, such as whole grains. Avoid foods high in saturated fats and inflammatory foods, like fast food.
Phase 2 (Follicular Phase) – Averages 16 days and overlaps with Phase 1:
This phase also starts on the first day of bleeding but continues until ovulation. The latter part of this phase is when an athlete may be at their highest risk for an ACL tear and may include:
Increased mood, alertness, and energy level
Increased adaption to strength and high intensity training
Alterations in joint laxity, which may increase the risk of soft tissue injuries
During this phase high-intensity strength and conditioning workouts continue to be better tolerated. However, due to the increased risk of soft tissue injuries, it may be best to implement a progressive warm-up and a thorough cool-down to decrease risk. Risk may be mitigated by making pre-hab more targeted with an emphasis on neuromuscular activation and to build up progressively to any short sharp changes in direction. An emphasis on recovery is critical. Additionally, in this phase, the key is keeping fuel consistent, ensuring enough carbohydrates, and including vitamin C. So, adding an orange, strawberries and banana to a smoothie could be a good option. In this phase a standard healthy and balanced diet is good.
Phase 3 (Ovulatory Phase) – 1-2 days
This phase starts when the dominant follicle releases a mature egg (ovulation), which usually occurs around day 14 of a 28-day cycle but can vary.
Phase 4 (Luteal Phase) – Typically the last14 days of the cycle:
The phase starts after ovulation and lasts until the start of the next menstrual period. During this phase, the symptoms athletes experience may be exacerbated, and they may not be driven to train. Athletes may also experience other signs/symptoms that include:
Low energy
Increasing muscle breakdown
Increased stress (which can also increase symptoms)
Increased appetite
Disrupted sleep (latter part of phase)
Increasing premenstrual symptoms (latter part of phase)
Decreased motivation to train (latter part of phase)
To manage this phase, it might be best to stick with endurance-based training. Coaches may also consider lowering the athlete’s peak power, which is the same benefit they will get from a reduced load/weights or reps. Focus on post-training recovery due to possible increased muscle breakdown. In the latter (pre-menstrual) part of this phase, focusing on good sleep habits is important, as well as continued moderate aerobic type exercise and relaxation methods such as yoga, which can help many with diminishing premenstrual symptoms. strategically including caffeine for low energy may also be beneficial. Additionally, in this phase having protein before and after training is particularly important. So, a smoothie with a scoop of protein powder added with some nut butter (unless allergic to nuts) and frozen fruit could be a good option. Protein, antioxidants, and complex carbohydrates – blueberries, oats and yogurt make a great post-training smoothie. As far as meals go, eating healthy fats like avocados and nuts, as well as eating mini meals throughout the day are recommended in this phase. Avoid processed foods/meats, fast foods, and those high in sugar in this phase. In the latter (pre-menstrual) part of this phase, focus on nutrient and fiber-rich foods, such as whole grains, fruits, and vegetables.
Please visit our home page for additional information on soccer related ACL injuries and researched strategies on how to help prevent them.
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