Assessment of Musculoskeletal Strength and Levels of Fatigue during Different Phases of Menstrual Cycle in Young Adults

Influence of menstrual cycle and oral contraceptive phases on strength performance, neuromuscular fatigue, and perceived exertion

The primary aim of the study was to assess differences in strength performance, neuromuscular fatigue, and perceived exertion across phases of the menstrual cycle [MC; early follicular (eFP), late follicular (lFP), and mid-luteal phase (mLP)] and oral contraceptives [OCs; active pill phase (aPP) and nonactive pill phase (nPP)]. The secondary aim was to analyze the influence of fluctuating serum 17β-estradiol and progesterone concentrations on these parameters in naturally menstruating women. Thirty-four women (21 with a natural MC and 13 using OCs) completed three or two experimental sessions, respectively. Mean propulsive velocity (MPVmean) and total number of repetitions (REPtotal) were assessed during a power [3 × 8 at 60% 1RM (one-repetition maximum)] and hypertrophy squat loading (3 sets to failure at 70% 1RM), respectively. Changes in bench press and squat MPV at 60% 1RM in response to the loadings were used as surrogates for nonlocal and local fatigue, respectively. Total blood lactate accumulation (BLAA) and markers of perceived exertion were assessed in each session. No significant differences between any of the MC or OC phases were observed for MPVmean, REPtotal, nonlocal and local fatigue, and markers of perceived exertion (all P > 0.050). A higher intraindividual 17β-estradiol concentration was significantly associated with a lower MPVmean (P = 0.019). BLAA was significantly higher in the lFP than in the mLP (P = 0.019) and negatively associated with the intraindividual progesterone concentration (P = 0.005). Although 17β-estradiol may negatively influence the MPV, it appears that fluctuations of both sex hormones across the MC and OC phases are not prominent enough to induce significant or practically relevant changes in the assessed parameters.NEW & NOTEWORTHY Although a high intraindividual 17β-estradiol concentration was associated with a lower movement velocity, markers of strength performance and surrogates for nonlocal and local fatigue remained unaffected by MC and OC phases. Blood lactate accumulation was significantly reduced in the mLP. Furthermore, our findings suggest that the impact of the MC phases varies greatly among individuals. Individuals with high fluctuations in sex hormone concentrations may experience relevant changes in the assessed parameters.

Minimal influence of the menstrual cycle or hormonal contraceptives on performance in female rugby league athletes

We examined performance across one menstrual cycle (MC) and 3 weeks of hormonal contraceptives (HC) use to identify whether known fluctuations in estrogen and progesterone/progestin are associated with functional performance changes. National Rugby League Indigenous Women's Academy athletes [n = 11 naturally menstruating (NM), n = 13 using HC] completed performance tests [countermovement jump (CMJ), squat jump (SJ), isometric mid-thigh pull, 20 m sprint, power pass and Stroop test] during three phases of a MC or three weeks of HC usage, confirmed through ovulation tests alongside serum estrogen and progesterone concentrations. MC phase or HC use did not influence jump height, peak force, sprint time, distance thrown or Stroop effect. However, there were small variations in kinetic and kinematic CMJ/SJ outputs. NM athletes produced greater mean concentric power in MC phase four than one [+0.41 W·kg-1 (+16.8%), p = 0.021] during the CMJ, alongside greater impulse at 50 ms at phase one than four [+1.7 N·s (+4.7%), p = 0.031] during the SJ, without differences between tests for HC users. Among NM athletes, estradiol negatively correlated with mean velocity and power (r = -0.44 to -0.50, p < 0.047), progesterone positively correlated with contraction time (r = 0.45, p = 0.045), and both negatively correlated with the rate of force development and impulse (r = -0.45 to -0.64, p < 0.043) during the SJ. During the CMJ, estradiol positively correlated to 200 ms impulse (r = 0.45, p = 0.049) and progesterone to mean power (r = 0.51, p = 0.021). Evidence of changes in testing performance across a MC, or during active HC use, is insufficient to justify "phase-based testing"; however, kinetic or kinematic outputs may be altered in NM athletes.

Mindful Self-Hypnosis Combined with Resistance Training to Reduce Perceived Stress and Improve Other Psychological Factors in Female College Students

Perceived stress is a significant problem among female college students that can impact psychological distress, sleep, and overall well-being. Mindful self-hypnosis (MSH) and resistance training (RT) have both been shown to reduce perceived stress. The rationale for the present study was to investigate whether MSH combined with RT could be more effective at reducing perceived stress as measured by the Perceived Stress Scale than RT alone due to synergistic effects achieved by combining the interventions. Forty-four female college students were randomized to one of the three groups: MSH+RT, RT only, or a wait-list control (WLC). Results indicated that, compared to RT only, the addition of MSH led to pronounced improvements in perceived stress which was significantly greater than WLC. Also, MSH+RT resulted in significant increases in mindfulness, sleep, strength, and well-being in comparison to WLC. MSH+RT was shown to be feasible with highly satisfactory participant ratings. Future research should examine the MSH+RT intervention with a larger population and with older women who are more at risk for stress and declining strength.

How do phases of the menstrual cycle affect sleep? A polysomnographic study of the EPISONO database

PURPOSE

Our study aimed to evaluate the impact of the menstrual cycle stages, especially menses, on sleep, inflammatory mediators, fatigue, anxiety, depression, and quality of life.

METHODS

We used data from the EPISONO study cohort, selecting 96 women who had undergone one-night polysomnography. The women were distributed in three groups according to the time point of the menstrual cycle on the polysomnography night: menses, mid/late follicular phase, and luteal phase. The volunteers completed questionnaires related to sleep quality, daytime sleepiness, insomnia, fatigue, anxiety, depression, and quality of life. Blood samples were collected to analyze interleukin 6, tumor necrosis factor-alpha, and C-reactive protein.

RESULTS

Sleep efficiency was statistically higher in women in the mid/late follicular group (89.9% ± 9.6) compared to menstrual (83.0% ± 10.8) and luteal (83.7% ± 12.7) groups. The mid/late follicular group presented a statistically significant reduction in sleep onset latency (7.1 ± 7.1 min) compared to the menstrual (22.3 ± 32.4 min) and luteal groups (15.9 ± 14.7 min). No statistical differences among the three groups were observed in other polysomnographic parameters, inflammatory mediators, daytime sleepiness, insomnia, fatigue, anxiety, depression, and quality of life.

CONCLUSIONS

Our findings demonstrate that the mid/late follicular phase might be beneficial for women's sleep, although there were no statistically changes in inflammatory mediators among the groups.

Effects of the menstrual cycle on the performance of female football players. A systematic review

Background

Women's football has been booming for a few years now, which has led to an increase in the expectation of the players' performance, leading to a more detailed study of women's physiology in the field of sports.

Objectives

To analyze the scientific evidence on the influence of menstruation on the performance of female footballers, as well as to analyze the methodological quality of the studies included in this review.

Materials and methods

The possible hormonal effects of the menstrual cycle phases on the performance of female footballers were analyzed. The databases used to conduct the searches were Pubmed, Scopus, Virtual Health Library, Web of Science, EBSCO and the Cochrane Library. All included studies met the inclusion criteria. The Cochrane risk of bias tool was used. This systematic review protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO: CRD42023390652).

Results

A total of nine clinical trials were included in this review. A low quality of evidence was observed in the studies. Not all the results support the idea that the menstrual cycle phases can alter the performance of female footballers.

Conclusion

This systematic review shows that there is a great deal of controversy about the influence of the menstrual cycle phases on the performance of female footballers. Studies are focused on solely biological factors and gender is normally no part of those studies. Further research with larger samples, and taking not only biological but also sociological factors, are necessary to determine the effects of menstruation on the performance of female footballers.

Perspectives on Concurrent Strength and Endurance Training in Healthy Adult Females: A Systematic Review

BACKGROUND

Both strength and endurance training are included in global exercise recommendations and are the main components of training programs for competitive sports. While an abundance of research has been published regarding concurrent strength and endurance training, only a small portion of this research has been conducted in females or has addressed their unique physiological circumstances (e.g., hormonal profiles related to menstrual cycle phase, menstrual dysfunction, and hormonal contraceptive use), which may influence training responses and adaptations.

OBJECTIVE

The aim was to complete a systematic review of the scientific literature regarding training adaptations following concurrent strength and endurance training in apparently healthy adult females.

METHODS

A systematic electronic search for articles was performed in July 2021 and again in December 2022 using PubMed and Medline. This review followed, where applicable, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included studies was assessed using a modified Downs and Black checklist. Inclusion criteria were (1) fully published peer-reviewed publications; (2) study published in English; (3) participants were healthy normal weight or overweight females of reproductive age (mean age between > 18 and < 50) or presented as a group (n > 5) in studies including both females and males and where female results were reported separately; (4) participants were randomly assigned to intervention groups, when warranted, and the study included measures of maximal strength and endurance performance; and (5) the duration of the intervention was ≥ 8 weeks to ensure a meaningful training duration.

RESULTS

Fourteen studies met the inclusion criteria (seven combined strength training with running, four with cycling, and three with rowing or cross-country skiing). These studies indicated that concurrent strength and endurance training generally increases parameters associated with strength and endurance performance in female participants, while several other health benefits such as, e.g., improved body composition and blood lipid profile were reported in individual studies. The presence of an "interference effect" in females could not be assessed from the included studies as this was not the focus of any included research and single-mode training groups were not always included alongside concurrent training groups. Importantly, the influence of concurrent training on fast-force production was limited, while the unique circumstances affecting females were not considered/reported in most studies. Overall study quality was low to moderate.

CONCLUSION

Concurrent strength and endurance training appears to be beneficial in increasing strength and endurance capacity in females; however, multiple research paradigms must be explored to better understand the influence of concurrent training modalities in females. Future research should explore the influence of concurrent strength and endurance training on fast-force production, the possible presence of an "interference effect" in athletic populations, and the influence of unique circumstances, such as hormone profile, on training responses and adaptations.

Are Whiplash-Associated Disorders and Temporomandibular Disorders in a Trauma Related Cause and Effect Relationship? A Review

Background: Whiplash is associated with a wide variety of clinical manifestations, including headache, neck pain, cervical rigidity, shoulder and back pain, paresthesia, vertigo, and temporomandibular disorders (TMDs). Previous studies reported that TMDs are more common in individuals with chronic whiplash-associated disorders (WAD) than in the general population; however, the pathophysiology and mechanism of this relationship are still not well understood. Methods: A PubMed and Ovid EMBASE review was performed to identify all studies addressing the trauma related cause and effect relationship between WAD and TMDs from January 2003 to March 2023. Results: After screening for eligibility and inclusion criteria, a total of 16 articles met the selection criteria. The various included studies discussed different aspects of the association between WDA and TMDs, including changes in the coordination and amplitude of jaw opening, the severity of the associated symptoms/signs in cases of WAD, the degree of fatigue and psychological stress, difficulty in feeding, cervical and myofascial pain, changes in the MRI signal at various muscle points, muscle tenderness, and quality of life. Conclusions: In this review, we summarized the clinical evidence of any trauma related cause and effect relationship between whiplash and TMDs. An accurate screening of the previous literature showed that, in conclusion, the relationship between whiplash and TMDs is still unclear.

The exercise power-duration relationship is equally reproducible in eumenorrheic female and male humans

This study aims to investigate the effect of the menstrual cycle (MC) on exercise performance across the power-duration relationship (PDR). We hypothesized females would exhibit greater variability in the PDR across the MC than males across a similar timespan, with critical power (CP) and work-prime (W') being lower during the early follicular phase than the late follicular and midluteal phases. Seven eumenorrheic, endurance-trained female adults performed multiple constant-load-to-task-failure and maximum-power tests at three timepoints across the MC (early follicular, late follicular, and midluteal phases). Ten endurance-trained male adults performed the same tests approximately 10 days apart. No differences across the PDR were observed between MC phases (CP: 186.74 ± 31.00 W, P = 0.955, CV = 0.81 ± 0.65%) (W': 7,961.81 ± 2,537.68 J, P = 0.476, CV = 10.48 ± 3.06%). CP was similar for male and female subjects (11.82 ± 1.42 W·kg^-1 vs. 11.56 ± 1.51 W·kg^-1, respectively) when controlling for leg lean mass. However, W' was larger (P = 0.047) for male subjects (617.28 ± 130.10 J·kg^-1) than female subjects (490.03 ± 136.70 J·kg^-1) when controlling for leg lean mass. MC phase does not need to be controlled when conducting aerobic endurance performance research on eumenorrheic female subjects without menstrual dysfunction. Nevertheless, several sex differences in the power-duration relationship exist, even after normalizing for body composition. Therefore, previous studies describing the physiology of exercise performance in male subjects may not perfectly describe that of female subjects.NEW & NOTEWORTHY Females are often excluded from exercise performance research due to experimental challenges in controlling for the menstrual cycle (MC), causing uncertainty regarding how the MC impacts female performance. The present study examined the influences that biological sex and the MC have on the power-duration relationship (PDR) by comparing critical power (CP), Work-prime (W'), and maximum power output (P_MAX) in males and females. Our data provide evidence that the MC does not influence the PDR and that females exhibit similar reproducibility as males. Thus, when conducting aerobic endurance exercise research on eumenorrheic females without menstrual dysfunction, the phase of the MC does not need to be controlled. Although differences in body composition account for some differences between the sexes, sex differences in W' and P_MAX persisted even after normalizing for different metrics of body composition. These data highlight the necessity and feasibility of examining sex differences in performance, as previously generated male-only data within the literature may not apply to female subjects.

Impact of the Menstrual Cycle Phases on the Movement Patterns of Sub-Elite Women Soccer Players during Competitive Matches

The purpose of this study was to evaluate the influence of the menstrual cycle phases on the movement patterns of sub-elite women soccer players during competitive matches over three consecutive seasons. Individual movement data were analyzed and compared in eight players from the second French League at the early follicular (EF), late follicular (LF) and mid-luteal (ML) phases of their menstrual cycle, determined by the calendar method. The movement patterns, expressed as meters per minute, were recorded during competitive matches using devices placed on the player’s ankle. Our results showed significantly lower distances covered at moderate and high velocity in the EF phase than in the LF and ML phases (Cohen’s d effect size = 1.03 and 0.79, respectively). The total distance covered during matches and the number of sprints also were reduced during EF compared with LF (d = 0.78 and 0.7, respectively). Overall, the total distance and distance covered at low velocity were significantly lower during the second half-time of the matches (d = 1.51), but no menstrual cycle phase × game period interaction was noted. In conclusion, our study suggests that EF may impact the movement pattern of sub-elite women soccer players during competitive matches, without any modulation of this effect by the playing time. Despite the low sample size, these results can be useful for coaches and support staff to modulate training loads and player rotation during soccer games.

Relationships between Sex and Adaptation to Physical Exercise in Young Athletes: A Pilot Study

The purpose of this study was to compare the redox, hormonal, metabolic, and lipid profiles of female and male basketball players during the seasonal training period, compared to their relative sedentary controls. 20 basketball players (10 female and 10 male) and 20 sedentary controls (10 female and 10 male) were enrolled in the study. Oxidative stress, adiponectin level, and metabolic profile were determined. Male and female athletes showed an increased antioxidant capacity (27% for males; 21% for females) and lactate level (389% for males; 460% for females) and reduced salivary cortisol (25% for males; 51% for females) compared to the sedentary controls. Moreover, a peculiar metabolite (in particular, amino acids and urea), hormonal, and lipidic profile were highlighted in the two groups of athletes. Female and male adaptations to training have several common traits, such as antioxidant potential enhancement, lactate increase, and activation of detoxifying processes, such as the urea cycle and arachidonic pathways as a response to inflammation. Moreover, we found different lipid and amino acid utilization related to sex. Deeper investigation could help coaches in developing training programs based on the athletes’ sex in order to reduce the drop-out rate of sporting activity by girls and fight the gender stereotypes in sport that also have repercussions in social fields.

The Disturbing Effect of Neuromuscular Fatigue on Postural Control Is Accentuated in the Premenstrual Phase in Female Athletes

This study explored the fatigue effect on postural control (PC) across menstrual cycle phases (MCPs) in female athletes. Isometric maximal voluntary contraction (IMVC), the center of pressure sway area (CoParea), CoP length in the medio-lateral (CoP_LX) and antero-posterior (CoP_LY) directions, and Y-balance test (YBT) were assessed before and after a fatiguing exercise during the follicular phase (FP), mid-luteal phase (LP), and premenstrual phase (PMP). Baseline normalized reach distances (NRDs) for the YBT were lower (p = 0.00) in the PMP compared to others MCPs, but the IMVC, CoParea, CoP_LX, and CoP_LY remained unchanged. After exercise, the IMVC and the NRD decrease was higher at PMP compared to FP (p = 0.00) and LP (p = 0.00). The CoParea, CoP_LX, and CoP_LY increase was higher in the PMP compared to FP (p = 0.00) and LP (p = 0.00). It was concluded that there is an accentuated PC impairment after exercise observed at PMP.

Bayesian Estimation of the Variation in Strength and Aerobic Physical Performances in Young Eumenorrheic Female College Students during a Menstrual Cycle

Background: The purpose of the present investigation was to examine changes in strength and aerobic physical performances in young eumenorrheic female college students during the menstruation phase and different testing occasions within a menstrual cycle. Methods: A repeated measure experimental design used to investigate the variation in physical performance from different testing occasions compared to the menstruation phase. Twelve eumenorrhea female college students volunteered to participate in this study. The participants were 19.8 ± 0.8 (±SD) years old, with the body mass of 61.4 ± 11.6 kg, the height of 162.6 ± 5.1 cm, and BMI of 23.2 ± 3.8. All participants reported regular monthly menstrual cycles of 26–33 days, none of whom reported taking oral contraceptives in their entire life. None of the participants was an athlete, and their level of activity was limited to physical education classes and recreational activities. The menstrual cycles during the two cycles before testing had to be between 26 and 35 days to participate in this study. Second, there had to be no current or ongoing neuromuscular diseases or musculoskeletal injuries. Third, no one should be taking any dietary or performance-enhancing supplements that could have affected testing results during this study. The participants tested on one-repetition maximum (1RM) bench press, 1RM leg press, push-up to failure, leg press with 60% of 1RM to failure, and running 1600 m time trial. The participants were tested on four occasions based on the classical model of the menstrual cycle (i.e., 28 days; early follicular phase (menstruation phase) on day 2 (T1), late follicular phase on day 8 (T2), ovulation phase on day 14 (T3), and mid-luteal phase on day 21 (T4)). Data were analyzed using the Bayesian hierarchical model (Bayesian Estimation) with Markov Chain Monte Carlo simulation using the decision-theoretic properties of the high-density interval (HDI) + ROPE decision rule. Results: The Bayesian estimated difference from the four testing occasions neither showed that the most credible parameter values (95% HDI) were sufficiently away from the null value nor showed that the most credible parameter values are close to the null value (Rope odds ratio among all tests were spread in 12.7% < 0 < 87.3% with an effect size ranging between d = −0.01 and 0.44). Hence, no decision can be made as to whether strength and aerobic physical performances change during the menstruation phase compared to the other testing occasions within a menstrual cycle. Conclusions: It was noticed that different studies concluded different results, which make the research in menstrual cycle difficult. However, the results from this study and published studies suggest that future research should investigate and profile motivation and autonomic nervous system activity during the menstruation phase and examine the interaction effect of the three on performance compared to other testing occasions within a menstrual cycle.

A Pilot Study on the Impact of Menstrual Cycle Phase on Elite Australian Football Athletes

The effect of the menstrual cycle on athlete performance, wellbeing and perceived exertion and fatigue is not well understood. Furthermore, it has not been investigated specifically in Australian Football athletes. This pilot study aimed to explore how naturally menstruating Australian Football athletes may be affected by menstrual cycle phase. The data collected from the routine monitoring of five naturally menstruating athletes (average menstrual cycle length of 28 ± 3 [SD] days) in one team (athlete age range 18–35 years) competing in the Women’s Australian Football League during the 2019 season were retrospectively analysed to compare performance (countermovement jump parameters and adductor squeeze pressure), perceived exertion, perceived fatigue and wellbeing (perceived sleep quality, stress and soreness) outcomes between the follicular and luteal phases. Performance, perceived exertion, stress and soreness did not appear to be affected by menstrual cycle phase (p > 0.17). However, perceived fatigue appeared to be significantly greater (p = 0.042) and sleep quality worse (p = 0.005) in the luteal phase. This pilot study suggests further research focusing on the effect of menstrual cycle phase on subjective fatigue and wellbeing is warranted.

The Specificities of Elite Female Athletes: A Multidisciplinary Approach

Female athletes have garnered considerable attention in the last few years as more and more women participate in sports events. However, despite the well-known repercussions of female sex hormones, few studies have investigated the specificities of elite female athletes. In this review, we present the current but still limited data on how normal menstrual phases, altered menstrual phases, and hormonal contraception affect both physical and cognitive performances in these elite athletes. To examine the implicated mechanisms, as well as the potential performances and health risks in this population, we then take a broader multidisciplinary approach and report on the causal/reciprocal relationships between hormonal status and mental and physical health in young (18-40 years) healthy females, both trained and untrained. We thus cover the research on both physiological and psychological variables, as well as on the Athlete Biological Passport used for anti-doping purposes. We consider the fairly frequent discrepancies and summarize the current knowledge in this new field of interest. Last, we conclude with some practical guidelines for eliciting improvements in physical and cognitive performance while minimizing the health risks for female athletes.

Effects of the Menstrual Cycle on Jumping, Sprinting and Force-Velocity Profiling in Resistance-Trained Women: A Preliminary Study

The aim of this study was to examine the effects of the menstrual cycle on vertical jumping, sprint performance and force-velocity profiling in resistance-trained women. A group of resistance-trained eumenorrheic women (n = 9) were tested in three phases over the menstrual cycle: bleeding phase, follicular phase, and luteal phase (i.e., days 1-3, 7-10, and 19-21 of the cycle, respectively). Each testing phase consisted of a battery of jumping tests (i.e., squat jump [SJ], countermovement jump [CMJ], drop jump from a 30 cm box [DJ30], and the reactive strength index) and 30 m sprint running test. Two different applications for smartphone (My Jump 2 and My Sprint) were used to record the jumping and sprinting trials, respectively, at high speed (240 fps). The repeated measures ANOVA reported no significant differences (p ≥ 0.05, ES < 0.25) in CMJ, DJ30, reactive strength index and sprint times between the different phases of the menstrual cycle. A greater SJ height performance was observed during the follicular phase compared to the bleeding phase (p = 0.033, ES = -0.22). No differences (p ≥ 0.05, ES < 0.45) were found in the CMJ and sprint force-velocity profile over the different phases of the menstrual cycle. Vertical jump, sprint performance and the force-velocity profiling remain constant in trained women, regardless of the phase of the menstrual cycle.

Serum Creatine Kinase Increases after Acute Strength Training in College Athletes with Menstrual Irregularities

Chronic menstrual dysfunction and low female sex hormones adversely affect muscular performance in women but studies in college athletes are scarce. A cohort of 18 Japanese, female college athletes at the University of Tsukuba, Japan, were recruited and studied over 3 weeks under 2 conditions. One group had normal menstrual cycling (CYC, 9 athletes) while the other had irregular cycles (DYS, 9 athletes). Hormones and creatine kinase (CK) were measured from blood under both rest (RE) and exercise (EX) conditions. Biceps femoris tendon stiffness was measured by myometry. No differences in age, height, weight, menarche age, or one-repetition maximum weight existed between the groups. The DYS group had persistently low levels of estrogen and progesterone. In the CYC group, the CK level significantly increased at each point immediately post-exercise and 24 h post-exercise compared to pre-exercise in Weeks 1 and 2, and significantly increased at 24 h post-exercise compared to pre-exercise status in Week 3. The DYS group was significantly different only between pre-exercise and 24 h post-exercise over all 3 weeks. The DYS group also suffered from higher biceps femoris tendon stiffness at 24 h post-exercise. Chronic menstrual irregularities in Japanese college athletes increase muscle damage markers in the bloodstream and muscle stiffness after acute strength training.

Training Habits of Eumenorrheic Active Women during the Different Phases of Their Menstrual Cycle: A Descriptive Study

The purpose of this study was to examine the training habits of eumenorrheic active women during their menstrual cycle (MC), and its perceived influence on physical performance regarding their athletic level. A group of 1250 sportswomen filled in a questionnaire referring to demographic information, athletic performance and MC-related training habits. Of the participants, 81% reported having a stable duration of MC, with most of them (57%) lasting 26-30 days. Concerning MC-related training habits, 79% indicated that their MC affects athletic performance, although 71% did not consider their MC in their training program, with no differences or modifications in training volume or in training intensity for low-level athletes (LLA) and high-level athletes (HLA) with hormonal contraceptive (HC) use. However, LLA with a normal MC adapted their training habits more, compared with HLA, also stopping their training (47.1% vs. 16.1%, respectively). Thus, different training strategies should be designed for HLA and LLA with a normal MC, but this is not so necessary for HLA and LLA who use HC. To sum up, training adaptations should be individually designed according to the training level and use or non-use of HC, always taking into account the pain suffered during the menstrual phase in most of the athletes.

The Impact of Menstrual Cycle Phase on Athletes' Performance: A Narrative Review

The effect of the menstrual cycle on physical performance is being increasingly recognised as a key consideration for women's sport and a critical field for further research. This narrative review explores the findings of studies investigating the effects of menstrual cycle phase on perceived and objectively measured performance in an athletic population. Studies examining perceived performance consistently report that female athletes identify their performance to be relatively worse during the early follicular and late luteal phases. Studies examining objective performance (using anaerobic, aerobic or strength-related tests) do not report clear, consistent effects of the impact of menstrual cycle phase on physical performance. Overall sport performance can be influenced by both perceived and physical factors. Hence, to optimise performance and management of eumenorrheic female athletes, there is a need for further research to quantify the impact of menstrual cycle phase on perceived and physical performance outcomes and to identify factors affecting variability in objective performance outcomes between studies.

Effects of Multi-Ingredient Preworkout Supplementation across a Five-Day Resistance and Endurance Training Microcycle in Middle-Aged Adults

Preworkout multi-ingredient admixtures are used to maximise exercise performance. The present double-blind, cross-over study compared the acute effects of ingesting a preworkout multi-ingredient (PREW) admixture vs. carbohydrate (CHO) over a week (microcycle) comprising three resistance training (RT) workouts alternated with two 30-min low-intensity endurance sessions (END) on RT volume (kg lifted) and END substrate oxidation. Additionally, postworkout decreases of muscle function and subjective responses were analysed. Following a baseline assessment, fourteen recreationally trained, middle-aged adults (seven females, 48.8 ± 4.7 years old) completed two identical microcycles separated by a two-week washout period while receiving either PREW or CHO (15 min prior to workout). The RT volume, per session (SVOL) and for the entire week (WVOL), was calculated. Fatty acid oxidation (FAO) during 30-min cycling corresponding to their individually determined maximal fat oxidation was measured using expired gasses and indirect calorimetry. Assessments of performance and tensiomyography were conducted within 20 min after each RT. Higher (p = 0.001) SVOL and WVOL along with a larger proportion of FAO (p = 0.05) during the second END workout were determined under the PREW treatment. No other statistically significant differences were observed between conditions. Compared to CHO, a preworkout multi-ingredient appears to increase resistance volume and favour fat oxidation during low-intensity endurance exercises.

Menstrual Cycle Effects on Exercise-Induced Fatigability

Estrogen and progesterone have distinct concentrations across the menstrual cycle, each one promoting several physiological alterations other than preparing the uterus for pregnancy. Whether these physiological alterations can influence motor output during a fatiguing contraction is the goal of this review, with an emphasis on the obtained effect sizes. Studies on this topic frequently attempt to report if there is a statistically significant difference in fatigability between the follicular and luteal phases of the menstrual cycle. Although the significant difference (the P-value) can inform the probability of the event, it does not indicate the magnitude of it. We also investigated whether the type of task performed (e.g., isometric vs. dynamic) can further influence the magnitude by which exercise-induced fatigue changes with fluctuations in the concentration of ovarian hormones. We retrieved experimental studies in eumenorrheic women published between 1975 and 2019. The initial search yielded 921 studies, and after manual refinement, 46 experimental studies that reported metrics of motor output in both the follicular and luteal phases of the menstrual cycle were included. From these retrieved studies, 15 showed a statistical difference between the luteal and follicular phases (seven showing less fatigability during the luteal phase and eight during the follicular phase). The effect size was not consistent across studies and with a large range (-6.77; 1.61, favoring the luteal and follicular phase, respectively). The inconsistencies across studies may be a consequence of the differences in the limb used during the fatiguing contraction (upper vs. lower extremity), the type of contraction (isometric vs. dynamic), the muscle mass engaged (single limb vs. full body), and the techniques used to define the menstrual cycle phase (e.g., serum concentration vs. reported day of menses). Further studies are required to determine the effects of a regular menstrual cycle phase on the exercise-induced fatigability.

The Influence of the Menstrual Cycle on Muscle Strength and Power Performance

This study aimed to investigate the fluctuations of muscle performance in the Smith machine half-squat exercise during three different phases of the menstrual cycle. Thirteen resistance-trained and eumenorrheic women volunteered to participate in the study (58.6 ± 7.8 kg, 31.1 ± 5.5 years). In a pre-experimental test, the half-squat one-repetition maximum (1RM) was measured. Body mass, tympanic temperature and urine concentration of the luteinizing hormone were estimated daily for ~30 days to determine the early follicular phase (EFP), the late follicular phase (LFP), and the mid-luteal phase (MLP) of the menstrual cycle. On the second day of each phase, performance of the Smith machine half-squats was assessed using 20, 40, 60 and 80% of one repetition maximum (1RM). In each load, force, velocity, and power output were measured during the concentric phase of the exercise by means of a rotatory encoder. The data were analyzed using one-way repeated measures ANOVA coupled with magnitude-based inferences. Overall, force, velocity and power output were very similar in all menstrual cycle phases with unclear differences in most of the pairwise comparisons and effect sizes >0.2. The results of this investigation suggest that eumenorrheic females have similar muscle strength and power performance in the Smith machine half-squat exercise during the EFP, LFP, and MLP phases of the menstrual cycle.