An observational study in Menstrual Cycle-based Periodized Training, Female Athlete Triad and Menstrual Cycle, sponsored by Martini Hospital Groningen. Recruiting at 2 sites in Netherlands. Open to female participants aged 12 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-07-28.
Sponsored by Martini Hospital Groningen · Observational
With an increase in number of female athletes in sport events, it is becoming more important to gain insight in female related sports physiology. A main difference between male anf female athletes is the menstrual cycle. During the menstrual cycle, female reproductive hormones fluctuate. These hormones are also of influence on endurance, recovery, muscle strenght and mental state. Therefore we hypothesize that training efficiancy, power and motivation to train differ during the menstrual cycle. In case there is a pattern seen during the menstrual cycle, training programs can be individualized taking the menstrual cycle into account leading to more effective training programs.
More and more women are trying to take their menstrual cycle into account when it comes to training effort, planning and performance. This is called menstrual cycle-based periodized training. However, it is still unknown what the exact influence of the different phases of the menstrual cycle is on training and performance. This includes the influence of hormonal fluctuations during the cycle on training capacity, effort load, restorative capacity, motivation to train and perform, daring to take risks and the mental aspects surrounding training and performance. As a result, general advice about cycle-based periodized training cannot be given at this time.
It has been described in the literature that professional-level cyclists regularly have menstrual cycle disorders (ie RED-s). This has short-term health consequences (less rapid recovery, fatigue) and long-term (osteoporosis, increased risk of cardiovascular disease). At a professional level, this knowledge is slowly penetrating. Less is known about the menstrual cycle of amateur athletes and there is also a lack of knowledge about the effects of the menstrual cycle on performance (endurance capacity, heart rate zones, power achieved).
To gain more insight into the menstrual cycle, the influence of the cycle on training and performance and the influence of training on the cycle of the sporting woman, the aim of this study is to monitor the menstrual cycle of female cyclists in combination with their subjective and objective training parameters. This allows us to create insight and, if useful, adapt training on an individual basis to the phase of the menstrual cycle.
The aim of this research is to investigate how the cyclists' menstrual cycle progresses and whether the cycle has an effect on performance.
Female JOIN cycling app members that consent with tracking the menstrual cycle.
Exclusion Criteria:
All female cyclist that consent using the data collected by JOIN cycling app and also give permission tracking thier menstrual cycle. Natrual menstrual cycle. Hormonal contraceptive use Intra-uterine device use (hormonal vs non-hormonal)
Behavioral: Adjusting training advice
Based on discomfort related to the menstrual cycle the female cyclist can choose to adjust the suggested training.
Health of menstrual cycle in amateur cyclist
It is known that the incidence of amenorrhea is about 15% of the professional female athletes. This has many short- and long term health consequences. These health consequences can be avoided since developing amenorrhea is preventable. It is unknown how many amateur cyclist have an irregular period or have amenorrhea. Insight in the size of this health problem creates a window of opportunity in preventive medicine.
Time frame: 1 year
Objective training parameters during the menstral cycle
By collecting details in regards to the menstrual cycle in combination with objective parameters (heart rate, power, speed, endurance) of training it is possible to investigate whether these objective parameters are influenced by the hormonal fluctuations during the menstrual cycle.
Time frame: 2 years
Subjective training parameters during the menstrual cycle
By collecting details in regards to the menstrual cycle in combination with subjective parameters (fatigue, discomfort, readiness, motivation) of training it is possible to investigate whether these subjective parameters are influenced by the hormonal fluctuations during the menstrual cycle.
Time frame: 2 years
Is menstrual cycle-based periodized training feasible in the future?
In case the menstrual cycle affects objective and subject training parameters, it might be feasible to adjust the training program based on the phase of the menstrual cycle.
Time frame: 2 years
Does the menstrual cycle affect recovery?
Improving endurance, muscle strength and power is not only training, but also the quality of recovery. Therefore, it is interesting to investigate whether the hormonal changes during the menstrual cycle affect recovery (i.e. readiness).
Time frame: 2 years
Questionnaires
Out of the complete cohort included, it is possible to select a specific group of cyclist to dive deeper into menstrual cycle related training parameters
Time frame: 3 years
Excercise testing
Out of the complete cohort included, it is possible to select a specific group of cyclist who can be invited to perform excercise tests during different moments of the menstrual cycle.
Time frame: 3 years
Plan to share: Undecided
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Female Athlete Triad Syndrome
Martini Hospital Groningen