Until recently, there has been less demand for and interest in female-specific sport and exercise science data. As a result, the vast majority of high-quality sport and exercise science data have been derived from studies with men as participants, which reduces the application of these data due to the known physiological differences between the sexes, specifically with regard to reproductive endocrinology. Furthermore, a shortage of specialist knowledge on female physiology in the sport science community, coupled with a reluctance to effectively adapt experimental designs to incorporate female-specific considerations, such as the menstrual cycle, hormonal contraceptive use, pregnancy and the menopause, has slowed the pursuit of knowledge in this field of research. In addition, a lack of agreement on the terminology and methodological approaches (i.e., gold-standard techniques) used within this research area has further hindered the ability of researchers to adequately develop evidenced-based guidelines for female exercisers. The purpose of this paper was to highlight the specific considerations needed when employing women (i.e., from athletes to non-athletes) as participants in sport and exercise science-based research. These considerations relate to participant selection criteria and adaptations for experimental design and address the diversity and complexities associated with female reproductive endocrinology across the lifespan. This statement intends to promote an increase in the inclusion of women as participants in studies related to sport and exercise science and an enhanced execution of these studies resulting in more high-quality female-specific data.

Purpose:To compare various measures of training load (TL) derived from physiological (heart rate [HR]), perceptual (rating of perceived exertion [RPE]), and physical (global positioning system [GPS] and accelerometer) data during in-season field-based training for professional soccer.Methods:Fifteen professional male soccer players (age 24.9 ± 5.4 y, body mass 77.6 ± 7.5 kg, height 181.1 ± 6.9 cm) were assessed in-season across 97 individual training sessions. Measures of external TL (total distance [TD], the volume of low-speed activity [LSA; <14.4 km/h], high-speed running [HSR; >14.4 km/h], very high-speed running [VHSR; >19.8 km/h], and player load), HR and session-RPE (sRPE) scores were recorded. Internal TL scores (HR-based and sRPE-based) were calculated, and their relationships with measures of external TL were quantified using Pearson product–moment correlations.Results:Physical measures of TD, LSA volume, and player load provided large, significant (r = .71−.84; P < .01) correlations with the HR-based and sRPE-based methods. Volume of HSR and VHSR provided moderate to large, significant (r = .40−.67; P < .01) correlations with measures of internal TL.Conclusions:While the volume of HSR and VHSR provided significant relationships with internal TL, physical-performance measures of TD, LSA volume, and player load appear to be more acceptable indicators of external TL, due to the greater magnitude of their correlations with measures of internal TL.

This article reviews the potential effects of the female steroid hormone fluctuations during the menstrual cycle on exercise performance. The measurement of estrogen and progesterone concentration to verify menstrual cycle phase is a major consideration in this review. However, even when hormone concentrations are measured, the combination of differences in timing of testing, the high inter- and intra-individual variability in estrogen and progesterone concentration, the pulsatile nature of their secretion and their interaction, may easily obscure possible effects of the menstrual cycle on exercise performance. When focusing on studies using hormone verification and electrical stimulation to ensure maximal neural activation, the current literature suggests that fluctuations in female reproductive hormones throughout the menstrual cycle do not affect muscle contractile characteristics. Most research also reports no changes over the menstrual cycle for the many determinants of maximal oxygen consumption (VO2max), such as lactate response to exercise, bodyweight, plasma volume, haemoglobin concentration, heart rate and ventilation. Therefore, it is not surprising that the current literature indicates that VO2max is not affected by the menstrual cycle. These findings suggest that regularly menstruating female athletes, competing in strength-specific sports and intense anaerobic/aerobic sports, do not need to adjust for menstrual cycle phase to maximise performance. For prolonged exercise performance, however, the menstrual cycle may have an effect. Even though most research suggests that oxygen consumption, heart rate and rating of perceived exertion responses to sub-maximal steady-state exercise are not affected by the menstrual cycle, several studies report a higher cardiovascular strain during moderate exercise in the mid-luteal phase. Nevertheless, time to exhaustion at sub-maximal exercise intensities shows no change over the menstrual cycle. The significance of this finding should be questioned due to the low reproducibility of the time to exhaustion test. During prolonged exercise in hot conditions, a decrease in exercise time to exhaustion is shown during the mid-luteal phase, when body temperature is elevated. Thus, the mid-luteal phase has a potential negative effect on prolonged exercise performance through elevated body temperature and potentially increased cardiovascular strain. Practical implications for female endurance athletes may be the adjustment of competition schedules to their menstrual cycle, especially in hot, humid conditions. The small scope of the current research and its methodological limitations warrant further investigation of the effect of the menstrual cycle on prolonged exercise performance.

Introduction The aim of this review is to provide methodological recommendations for menstrual cycle research in exercise science and sports medicine based on a review of recent literature. Research in this area is growing but often reports conflicting results, and it is proposed that some of this may be explained by methodological issues. Methods This review examined the menstrual cycle verification methods used in recent literature on exercise performance over the menstrual cycle identified through a literature search of PubMed and SportDiscus from 2008 until 2018. Results Potential changes over the menstrual cycle are likely related to hormone fluctuations; however, only 44% of the selected studies measured the actual concentrations of the female steroid hormones estrogen and progesterone. It was shown that the likely inclusion of participants with anovulatory or luteal phase–deficient cycles in combination with small participant numbers has affected results in recent menstrual cycle research and, consequently, our understanding of this area. Conclusion To improve the quality of future menstrual cycle research, it is recommended that a combination of three methods is used to verify menstrual cycle phase: the calendar-based counting method combined with urinary luteinizing hormone surge testing and the measurement of serum estrogen and progesterone concentrations at the time of testing. A strict luteal phase verification limit of >16 nmol·L−1 for progesterone should be set. It is also recommended that future research should focus on the inclusion of the late follicular estrogen peak. It is envisaged that these methodological recommendations will assist in clarifying some of the disagreement around the effects of the menstrual cycle on exercise performance and other aspects of exercise science and sports medicine.

During their reproductive years the hormone levels in women fluctuate due to the menstrual cycle. The four hormonal markers of the menstrual cycle (oestrogen, progesterone, follicle stimulating hormone (FSH) and luteinising hormone (LH)) change continuously throughout the cycle. These fluctuations in female steroid hormones affect the autonomic nervous system and metabolic functions (Florini, 1987). Therefore certain physiological parameters and athletic performance could change along with the menstrual cycle phases (Becker et al. 1982). However, the influence of the menstrual cycle phase on exercise performance, particularly muscle strength, is unclear. Sarwar et al. (1996) tested skeletal muscle strength, relaxation rate and fatiguability of the quadriceps during the menstrual cycle. They found no changes in these parameters for women taking oral contraceptives. For women not taking oral contraceptives, however, the quadriceps were stronger, more fatiguable and had a longer relaxation time at mid-cycle (day 12-18). Phillips et al. (1996) reported a higher adductor pollicis strength during the follicular phase than during the luteal phase, with a rapid decrease in strength around ovulation. They suggested that oestrogen has a strengthening action on skeletal muscle, although the underlying mechanism is not clear. Greeves et al. (1999), however, reported the highest quadriceps strength during the mid-luteal phase and found a positive relationship between strength and progesterone concentration. Several other studies have found no changes in skeletal muscle strength over the menstrual cycle (DiBrezzo et al. 1991;Quadango et al. 1991;Lebrun et al. 1995;Gür, 1997).The main problem in the measurement of maximum voluntary strength is ensuring that the contraction truly reflects the maximum force-generating capacity of the muscle. Even well-motivated subjects may not always reach full neural activation of their muscles (Rutherford et al. 1986). The extent of neural activation can be evaluated by applying a superimposed electrical stimulus to the muscle during the performance of a maximal voluntary contraction (MVC). When comparing strength over a period of time, such as in menstrual cycle research, it is especially important to ensure maximal neural activation during each test.A further problem encountered in research on the influence of the menstrual cycle on physical performance is the timing of the testing. It is difficult to predict the exact phases of the menstrual cycle and the concurrent reproductive hormone concentrations. Counting days 1. The influence of the different phases of the menstrual cycle on skeletal muscle contractile characteristics was studied in 19 regularly menstruating women. Muscle function was measured when (i) oestrogen and progesterone concentrations were low (menstruation), (ii) oestrogen was elevated and progesterone was low (late follicular phase), and (iii) oestrogen and progesterone were both elevated (luteal phase).2. Maximal isometric quadriceps strength, fatiguability and electrica...