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2.
J Sports Sci ; 41(6): 565-572, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37343951

ABSTRACT

This study investigated the impact of match location and travel modality on physical performance of an Australian A-League association football team. Match location comprised of a home vs away comparison; while travel modality compared home matches, road travel, short-flight travel, and long-flight travel. Both models accounted for match result, opposition quality and total distance covered. Physical performance was defined as average running intensity (m.min-1), low-speed activity (LSA), high-speed activity (HSA), very high-speed activity (VHSA), high-intensity efforts (HIE) and sprint efforts. Statistical significance was accepted at p < 0.05. Match location results demonstrated significantly greater average running intensity and LSA for away matches and significantly greater HSA for home matches. Travel modality results demonstrated significantly greater LSA for road travel compared to home matches and long-flight travel, while HSA was significantly greater for home matches and long-flight travel than for road travel. Additionally, home matches demonstrated significantly greater VHSA than road travel. Assessing the impact of travel modality on physical performance provides more contextual information than solely home vs away. Coaches may use this information to plan travel to mitigate detrimental effects on physical performance, particularly concerning road travel on matchdays.


Subject(s)
Athletic Performance , Rugby , Humans , Australia , Geographic Information Systems , Physical Functional Performance
3.
J Int Soc Sports Nutr ; 20(1): 2204066, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37221858

ABSTRACT

Based on a comprehensive review and critical analysis of the literature regarding the nutritional concerns of female athletes, conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society: 1. Female athletes have unique and unpredictable hormone profiles, which influence their physiology and nutritional needs across their lifespan. To understand how perturbations in these hormones affect the individual, we recommend that female athletes of reproductive age should track their hormonal status (natural, hormone driven) against training and recovery to determine their individual patterns and needs and peri and post-menopausal athletes should track against training and recovery metrics to determine the individuals' unique patterns. 2. The primary nutritional consideration for all athletes, and in particular, female athletes, should be achieving adequate energy intake to meet their energy requirements and to achieve an optimal energy availability (EA); with a focus on the timing of meals in relation to exercise to improve training adaptations, performance, and athlete health. 3. Significant sex differences and sex hormone influences on carbohydrate and lipid metabolism are apparent, therefore we recommend first ensuring athletes meet their carbohydrate needs across all phases of the menstrual cycle. Secondly, tailoring carbohydrate intake to hormonal status with an emphasis on greater carbohydrate intake and availability during the active pill weeks of oral contraceptive users and during the luteal phase of the menstrual cycle where there is a greater effect of sex hormone suppression on gluconogenesis output during exercise. 4. Based upon the limited research available, we recommend that pre-menopausal, eumenorrheic, and oral contraceptives using female athletes should aim to consume a source of high-quality protein as close to beginning and/or after completion of exercise as possible to reduce exercise-induced amino acid oxidative losses and initiate muscle protein remodeling and repair at a dose of 0.32-0.38 g·kg-1. For eumenorrheic women, ingestion during the luteal phase should aim for the upper end of the range due to the catabolic actions of progesterone and greater need for amino acids. 5. Close to the beginning and/or after completion of exercise, peri- and post-menopausal athletes should aim for a bolus of high EAA-containing (~10 g) intact protein sources or supplements to overcome anabolic resistance. 6. Daily protein intake should fall within the mid- to upper ranges of current sport nutrition guidelines (1.4-2.2 g·kg-1·day-1) for women at all stages of menstrual function (pre-, peri-, post-menopausal, and contraceptive users) with protein doses evenly distributed, every 3-4 h, across the day. Eumenorrheic athletes in the luteal phase and peri/post-menopausal athletes, regardless of sport, should aim for the upper end of the range. 7. Female sex hormones affect fluid dynamics and electrolyte handling. A greater predisposition to hyponatremia occurs in times of elevated progesterone, and in menopausal women, who are slower to excrete water. Additionally, females have less absolute and relative fluid available to lose via sweating than males, making the physiological consequences of fluid loss more severe, particularly in the luteal phase. 8. Evidence for sex-specific supplementation is lacking due to the paucity of female-specific research and any differential effects in females. Caffeine, iron, and creatine have the most evidence for use in females. Both iron and creatine are highly efficacious for female athletes. Creatine supplementation of 3 to 5 g per day is recommended for the mechanistic support of creatine supplementation with regard to muscle protein kinetics, growth factors, satellite cells, myogenic transcription factors, glycogen and calcium regulation, oxidative stress, and inflammation. Post-menopausal females benefit from bone health, mental health, and skeletal muscle size and function when consuming higher doses of creatine (0.3 g·kg-1·d-1). 9. To foster and promote high-quality research investigations involving female athletes, researchers are first encouraged to stop excluding females unless the primary endpoints are directly influenced by sex-specific mechanisms. In all investigative scenarios, researchers across the globe are encouraged to inquire and report upon more detailed information surrounding the athlete's hormonal status, including menstrual status (days since menses, length of period, duration of cycle, etc.) and/or hormonal contraceptive details and/or menopausal status.


Subject(s)
Creatine , Sports , Female , Humans , Male , Progesterone , Athletes , Amino Acids
4.
Med Sci Sports Exerc ; 54(10): 1678-1689, 2022 10 01.
Article in English | MEDLINE | ID: mdl-36106832

ABSTRACT

PURPOSE: We aimed to study variations in strength and power performance during the menstrual cycle (MC) in eumenorrheic young women and during the pill cycle in oral contraceptives (OC) users. METHODS: Forty healthy, normal-weight women between 18 and 35 yr (n = 30 eumenorrheic women; n = 10 OC users) completed this prospective cohort study. Seven to nine times during the MC/pill-cycle, the participants completed a physical performance test series, a questionnaire about psychological well-being, blood sampling, and determination of body mass. The physical tests included isometric handgrip strength, elbow flexor strength, countermovement jump (CMJ) height, and a 10-s Wingate bike test. RESULTS: No direct correlation was observed between the variations in sex hormones and physical performance parameters. However, positive correlations were observed between physical performance outcomes and self-reported motivation, perception of own physical performance level, pleasure level, and arousal level. CMJ was 6% lower in the late luteal phase (LL) compared with the midluteal phase (ML) (P = 0.04). Wingate peak power was 3% lower in early follicular (EF) compared with the ML (P = 0.04). Furthermore, Wingate average power was 2%-5% lower in LL compared with all other MC phases. In line with these observations, physical pain was higher in EF and LL, and the pleasure level was lower in EF compared with the other MC phases. In OC users, we observed no variation in performance and self-reported parameters between the placebo-pill phase and the OC-pill phase. CONCLUSIONS: Impairments in CMJ and Wingate performance were observed at the end and start of MC compared with other MC phases, which were associated with lower psychological well-being, but not the sex hormone fluctuations.


Subject(s)
Hand Strength , Menstrual Cycle , Contraceptives, Oral , Female , Gonadal Steroid Hormones , Humans , Menstrual Cycle/physiology , Muscles , Prospective Studies
6.
J Strength Cond Res ; 36(2): 392-399, 2022 Feb 01.
Article in English | MEDLINE | ID: mdl-31855928

ABSTRACT

ABSTRACT: Barba-Moreno, L, Cupeiro, R, Romero-Parra, N, Janse de Jonge, XA, and Peinado, AB. Cardiorespiratory Responses to Endurance Exercise Over the Menstrual Cycle and With Oral Contraceptive Use. J Strength Cond Res 36(2): 392-399, 2022-Female steroid hormone fluctuations during the menstrual cycle and exogenous hormones from oral contraceptives may have potential effects on exercise performance. The aim of this study was to investigate the effects of these fluctuations on cardiorespiratory responses during steady-state exercise in women. Twenty-three healthy endurance-trained women performed 40 minutes of running at 75% of their maximal aerobic speed during different phases of the menstrual cycle (n = 15; early follicular phase, midfollicular phase, and luteal phase) or oral contraceptive cycle (n = 8; hormonal phase and nonhormonal phase). Ventilatory parameters and heart rate (HR) were measured. Data were analyzed using a mixed linear model. For the eumenorrheic group, significantly higher oxygen uptake (p = 0.049) and percentage of maximum oxygen uptake (p = 0.035) were observed during the midfollicular phase compared with the early follicular. Heart rate (p = 0.004), oxygen ventilatory equivalent (p = 0.042), carbon dioxide ventilatory equivalent (p = 0.017), and tidal volume (p = 0.024) increased during luteal phase in comparison with midfollicular. In oral contraceptive users, ventilation (p = 0.030), breathing frequency (p = 0.018), oxygen ventilatory equivalent (p = 0.032), and carbon dioxide ventilatory equivalent (p = 0.001) increased during the hormonal phase. No significant differences were found for the rest of the parameters or phases. Both the eumenorrheic group and oral contraceptive group showed a significant increase in some ventilatory parameters during luteal and hormonal phases, respectively, suggesting lower cardiorespiratory efficiency. However, the lack of clinical meaningfulness of these differences and the nondifferences of other physiological variables, indicate that the menstrual cycle had a small impact on submaximal exercise in the current study.


Subject(s)
Oxygen Consumption , Oxygen , Contraceptives, Oral , Female , Follicular Phase , Humans , Menstrual Cycle
7.
Article in English | MEDLINE | ID: mdl-34682310

ABSTRACT

Most reproductive-aged women are exposed to fluctuating female steroid hormones due to the menstrual cycle or oral contraceptive use. This study investigated the potential effect of the menstrual cycle and combined monophasic oral contraceptive cycle on various aspects of muscle performance. Thirty active females (12 with a natural menstrual cycle, 10 taking a high-androgenicity oral contraceptive and 8 taking a low-androgenicity oral contraceptive), aged 18 to 30 years, were tested three times throughout one menstrual or oral contraceptive cycle. Counter-movement jumps, bilateral hop jumps, handgrip strength, isometric knee extensor strength and isokinetic knee flexion and extension were assessed. Perceptual ratings of fatigue, muscle soreness, pain and mood were recorded. Most variables showed no significant changes over the menstrual or oral contraceptive cycle. However, for the menstrual cycle group, isokinetic knee flexion at 240° s-1, and time of flight in bilateral hopping and counter movement jumps showed better results during the mid-luteal phase compared with the late follicular phase. For the high-androgenicity oral contraceptive group, isokinetic knee flexion at 240° s-1 was significantly higher in the late hormone phase compared with the early hormone phase. For the low-androgenicity oral contraceptive group, time of flight for the counter-movement jumps was lower in the late hormone phase compared with the early hormone phase. The findings indicate that faster and explosive aspects of muscle performance may be influenced by endogenous and exogenous female hormones.


Subject(s)
Hand Strength , Menstrual Cycle , Adult , Contraceptives, Oral, Combined , Female , Follicular Phase , Humans , Muscles
8.
Eur J Appl Physiol ; 121(11): 3051-3059, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34296342

ABSTRACT

PURPOSE: This study aimed to investigate the effect of fluctuating female hormones during the menstrual cycle (MC) and oral contraceptive (OC) cycle on different measures of body composition. METHODS: Twenty-two women with a natural MC and thirty women currently taking combined monophasic OC were assessed over three phases of the menstrual or oral contraceptive cycle. Body weight, skinfolds, bioelectric impedance analysis (BIA), ultrasound, dual-energy X-ray absorptiometry (DXA), and peripheral quantitative computed tomography (pQCT) measurements were performed to assess body composition. Urine specific gravity (USG) was measured as an indication of hydration, and serum oestradiol and progesterone were measured to confirm cycle phases. RESULTS: Five participants with a natural MC were excluded based on the hormone analysis. For the remaining participants, no significant changes over the MC and OC cycle were found for body weight, USG, skinfolds, BIA, ultrasound and pQCT measures. However, DXA body fat percentage and fat mass were lower in the late follicular phase compared to the mid-luteal phase of the MC, while for the OC cycle, DXA body fat percentage was higher and lean mass lower in the early hormone phase compared with the late hormone phase. CONCLUSION: Our findings suggest that assessment of body fat percentage through BIA and skinfolds may be performed without considering the MC or OC cycle. Body adiposity assessment via DXA, however, may be affected by female hormone fluctuations and therefore, it may be advisable to perform repeat testing using DXA during the same phase of the MC or OC cycle.


Subject(s)
Body Composition , Contraceptives, Oral/pharmacology , Estradiol/blood , Menstrual Cycle/physiology , Progesterone/blood , Absorptiometry, Photon , Adolescent , Adult , Anthropometry/methods , Female , Humans , Specific Gravity , Tomography, X-Ray Computed
9.
Article in English | MEDLINE | ID: mdl-33498274

ABSTRACT

The aim of this study was to analyse the impact of sex hormone fluctuations throughout the menstrual cycle on cardiorespiratory response to high-intensity interval exercise in athletes. Twenty-one eumenorrheic endurance-trained females performed an interval running protocol in three menstrual cycle phases: early-follicular phase (EFP), late-follicular phase (LFP) and mid-luteal phase (MLP). It consisted of 8 × 3-min bouts at 85% of their maximal aerobic speed with 90-s recovery at 30% of their maximal aerobic speed. To verify menstrual cycle phase, we applied a three-step method: calendar-based counting, urinary luteinizing hormone measurement and serum hormone analysis. Mixed-linear model for repeated measures showed menstrual cycle impact on ventilatory (EFP: 78.61 ± 11.09; LFP: 76.45 ± 11.37; MLP: 78.59 ± 13.43) and heart rate (EFP: 167.29 ± 11.44; LFP: 169.89 ± 10.62; MLP: 169.89 ± 11.35) response to high-intensity interval exercise (F2.59 = 4.300; p = 0.018 and F2.61 = 4.648; p = 0.013, respectively). Oxygen consumption, carbon dioxide production, respiratory exchange ratio, breathing frequency, energy expenditure, relative perceived exertion and perceived readiness were unaltered by menstrual cycle phase. Most of the cardiorespiratory variables measured appear to be impassive by menstrual cycle phases throughout a high-intensity interval exercise in endurance-trained athletes. It seems that sex hormone fluctuations throughout the menstrual cycle are not high enough to disrupt tissues' adjustments caused by the high-intensity exercise. Nevertheless, HR based training programs should consider menstrual cycle phase.


Subject(s)
Exercise , Follicular Phase , Female , Humans , Luteal Phase , Menstrual Cycle , Oxygen Consumption , Progesterone
10.
J Strength Cond Res ; 35(2): 353-359, 2021 Feb 01.
Article in English | MEDLINE | ID: mdl-33337689

ABSTRACT

ABSTRACT: Romero-Parra, N, Rael, B, Alfaro-Magallanes, VM, Janse de Jonge, X, Cupeiro, R, and Peinado, AB; On Behalf of the IronFEMME Study Group. The effect of the oral contraceptive cycle phase on exercise-induced muscle damage after eccentric exercise in resistance-trained women. J Strength Cond Res 35(2): 353-359, 2021-To evaluate the influence of the active pill phase versus withdrawal phase of a monophasic oral contraceptive (OC) cycle on exercise-induced muscle damage and inflammation after eccentric resistance exercise. Eighteen resistance-trained female OC users (age: 25.6 ± 4.2 years, height: 162.4 ± 5.0 cm, and body mass: 58.1 ± 5.7 kg) performed an eccentric squat-based exercise during the active pill phase and withdrawal phase of their OC cycle. Muscle soreness, counter movement jump (CMJ), and blood markers of muscle damage and inflammation were evaluated before and postexercise (0, 2, 24, and 48 hours). Creatine kinase (CK) values were higher in the withdrawal (181.8 ± 89.8 U·L-1) than in the active pill phase (144.0 ± 39.7 U·L-1) (p < 0.001). The highest CK concentrations and muscle soreness values were observed 24 hours postexercise (217.9 ± 117.5 U·L-1 and 44.7 ± 19.7, respectively) compared with baseline (115.3 ± 37.4 U·L-1 and 4.4 ± 9.2, respectively; p < 0.001). In addition, a decrease in CMJ immediately postexercise (20.23 ± 4.6 cm) was observed in comparison with baseline (24.2 ± 6.1 cm), which was not yet recovered 24 hours postexercise (21.9 ± 5.9 cm; p < 0.001). No other phase or time effects were observed. An eccentric squat-based exercise session elicits muscle damage but no inflammation response in resistance-trained women. Furthermore, the highest CK concentrations observed in the withdrawal phase suggest that this phase might be more vulnerable to muscle damage and, therefore, less adequate to administer high training loads. However, the lack of differences in other muscle damage variables between OC phases does not warrant any guidance on the active pill versus withdrawal phase.


Subject(s)
Exercise , Muscle, Skeletal , Adult , Contraceptives, Oral , Creatine Kinase , Female , Humans , Myalgia/etiology , Young Adult
11.
Int J Sports Physiol Perform ; 16(3): 375-381, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33004685

ABSTRACT

PURPOSE: The influence of female sex hormones on body fluid regulation and metabolism homeostasis has been widely studied. However, it remains unclear whether hormone fluctuations throughout the menstrual cycle (MC) and with oral contraceptive (OC) use affect body composition (BC). Thus, the aim of this study was to investigate BC over the MC and OC cycle in well-trained females. METHODS: A total of 52 eumenorrheic and 33 monophasic OC-taking well-trained females participated in this study. Several BC variables were measured through bioelectrical impedance analysis 3 times in the eumenorrheic group (early follicular phase, late follicular phase, and midluteal phase) and on 2 occasions in the OC group (withdrawal phase and active pill phase). RESULTS: Mixed linear model tests reported no significant differences in the BC variables (body weight, body mass index, basal metabolism, fat mass, fat-free mass, and total body water) between the MC phases or between the OC phases (P > .05 for all comparisons). Trivial and small effect sizes were found for all BC variables when comparing the MC phases in eumenorrheic females, as well as for the OC cycle phases. CONCLUSIONS: According to the results, sex hormone fluctuations throughout the menstrual and OC cycle do not influence BC variables measured by bioelectrical impedance in well-trained females. Therefore, it seems that bioimpedance analysis can be conducted at any moment of the cycle, both for eumenorrheic women and women using OC.


Subject(s)
Body Composition , Contraceptives, Oral , Menstrual Cycle , Athletes , Electric Impedance , Female , Humans
12.
J Cancer Surviv ; 15(2): 244-258, 2021 04.
Article in English | MEDLINE | ID: mdl-32803533

ABSTRACT

PURPOSE: Manual lymphatic drainage (MLD) massage is widely accepted as a conservative treatment for lymphedema. This systematic review aims to examine the methodologies used in recent research and evaluate the effectiveness of MLD for those at-risk of or living with lymphedema. METHODS: The electronic databases Embase, PubMed, CINAHL Complete and Cochrane Central Register of Controlled Trials were searched using relevant terms. Studies comparing MLD with another intervention or control in patients at-risk of or with lymphedema were included. Studies were critically appraised with the PEDro scale. RESULTS: Seventeen studies with a total of 867 female and two male participants were included. Only studies examining breast cancer-related lymphedema were identified. Some studies reported positive effects of MLD on volume reduction, quality of life and symptom-related outcomes compared with other treatments, while other studies reported no additional benefit of MLD as a component of complex decongestive therapy. In patients at-risk, MLD was reported to reduce incidence of lymphedema in some studies, while others reported no such benefits. CONCLUSIONS: The reviewed articles reported conflicting findings and were often limited by methodological issues. This review highlights the need for further experimental studies on the effectiveness of MLD in lymphedema. IMPLICATIONS FOR CANCER SURVIVORS: There is some evidence that MLD in early stages following breast cancer surgery may help prevent progression to clinical lymphedema. MLD may also provide additional benefits in volume reduction for mild lymphedema. However, in moderate to severe lymphedema, MLD may not provide additional benefit when combined with complex decongestive therapy.


Subject(s)
Breast Neoplasms , Lymphedema , Breast Neoplasms/surgery , Breast Neoplasms/therapy , Female , Humans , Lymphedema/therapy , Male , Manual Lymphatic Drainage , Mastectomy , Quality of Life
13.
Front Physiol ; 11: 629, 2020.
Article in English | MEDLINE | ID: mdl-32595523

ABSTRACT

INTRODUCTION: Oral contraceptive (OC) use influences peak exercise responses to training, however, the influence of OC on central and peripheral adaptations to exercise training are unknown. This study investigated the influence of OC use on changes in time-to-fatigue, pulmonary oxygen uptake, cardiac output, and heart rate on-kinetics, as well as tissue saturation index to 4 weeks of sprint interval training in recreationally active women. METHODS: Women taking an oral contraceptive (OC; n = 25) or experiencing natural menstrual cycles (MC; n = 22) completed an incremental exercise test to volitional exhaustion followed by a square-wave step-transition protocol to moderate (90% of power output at ventilatory threshold) and high intensity (Δ50% of power output at ventilatory threshold) exercise on two separate occasions. Time-to-fatigue, pulmonary oxygen uptake on-kinetics, cardiac output, and heart rate on-kinetics, and tissue saturation index responses were assessed prior to, and following 12 sessions of sprint interval training (10 min × 1 min efforts at 100-120% PPO in a 1:2 work:rest ratio) completed over 4 weeks. RESULTS: Time-to-fatigue increased in both groups following training (p < 0.001), with no difference between groups. All cardiovascular on-kinetic parameters improved to the same extent following training in both groups. Greater improvements in pulmonary oxygen up-take kinetics were seen at both intensities in the MC group (p < 0.05 from pre-training) but were blunted in the OC group (p > 0.05 from pre-training). In contrast, changes in tissue saturation index were greater in the OC group at both intensities (p < 0.05); with the MC group showing no changes at either intensity. DISCUSSION: Oral contraceptive use may reduce central adaptations to sprint interval training in women without influencing improvements in exercise performance - potentially due to greater peripheral adaptation. This may be due to the influence of exogenous oestradiol and progestogen on cardiovascular function and skeletal muscle blood flow. Further investigation into female-specific influences on training adaptation and exercise performance is warranted.

14.
Sports Med ; 50(1): 171-185, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31677121

ABSTRACT

BACKGROUND: Resistance training is well known to increase strength and lean body mass, and plays a key role in many female athletic and recreational training programs. Most females train throughout their reproductive years when they are exposed to continuously changing female steroid hormone profiles due to the menstrual cycle or contraceptive use. Therefore, it is important to focus on how female hormones may affect resistance training responses. OBJECTIVE: The aim of this systematic review is to identify and critically appraise current studies on the effect of the menstrual cycle and oral contraceptives on responses to resistance training. METHODS: The electronic databases Embase, PubMed, SPORTDiscus and Web of Science were searched using a comprehensive list of relevant terms. Studies that investigated the effect of the menstrual cycle phase or oral contraceptive cycle on resistance training responses were included. Studies were also included if they compared resistance training responses between the natural menstrual cycle and oral contraceptive use, or if resistance training was adapted to the menstrual cycle phase or oral contraceptive phase. Studies were critically appraised with the McMasters Universities Critical Review Form for Quantitative Studies and relevant data were extracted. RESULTS: Of 2007 articles found, 17 studies met the criteria and were included in this systematic review. The 17 included studies had a total of 418 participants with an age range of 18-38 years. One of the 17 studies found no significant differences in acute responses to a resistance training session over the natural menstrual cycle, while four studies did find changes. When assessing the differences in acute responses between the oral contraceptive and menstrual cycle groups, two studies reported oral contraceptives to have a positive influence, whilst four studies reported that oral contraceptive users had a delayed recovery, higher levels of markers of muscle damage, or both. For the responses to a resistance training program, three studies reported follicular phase-based training to be superior to luteal phase-based training or regular training, while one study reported no differences. In addition, one study reported no differences in strength development between oral contraceptive and menstrual cycle groups. One further study reported a greater increase in type I muscle fibre area and a trend toward a greater increase in muscle mass within low-androgenic oral contraceptive users compared with participants not taking hormonal contraceptives. Finally, one study investigated androgenicity of oral contraceptives and showed greater strength developments with high androgenic compared with anti-androgenic oral contraceptive use. CONCLUSIONS: The reviewed articles reported conflicting findings, and were often limited by small participant numbers and methodological issues, but do appear to suggest female hormones may affect resistance training responses. The findings of this review highlight the need for further experimental studies on the effects of the menstrual cycle and oral contraceptives on acute and chronic responses to resistance training.


Subject(s)
Body Composition , Contraceptives, Oral/pharmacology , Menstrual Cycle , Muscle Strength , Resistance Training , Female , Humans
15.
Med Sci Sports Exerc ; 51(12): 2610-2617, 2019 12.
Article in English | MEDLINE | ID: mdl-31246715

ABSTRACT

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 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.


Subject(s)
Exercise/physiology , Menstrual Cycle , Research Design/standards , Sports/physiology , Athletic Performance/physiology , Body Temperature , Estrogens/analysis , Estrogens/blood , Female , Humans , Luteinizing Hormone/urine , Progesterone/analysis , Progesterone/blood , Saliva/chemistry
16.
Int J Sports Physiol Perform ; 13(1): 82-87, 2018 Jan 01.
Article in English | MEDLINE | ID: mdl-28459358

ABSTRACT

PURPOSE: Menstruation and menstrual symptoms are commonly cited barriers to physical activity in women. The delay or avoidance of menstruation through extended oral-contraceptive (OC) regimens may mitigate these barriers, yet information on menstrual-manipulation practices in young physically active women is sparse. The objective of this study was to investigate prevalence of, and reasons for, menstrual manipulation with OCs in recreationally and competitively active women. METHODS: One hundred ninety-one recreationally active (self-reported moderate to vigorous physical activity 150-300 min/wk) women (age 23 ± 5 y), 160 subelite recreationally active (self-reported moderate to vigorous physical activity >300 min/wk) women (age 23 ± 5 y), and 108 competitive (state-, national- or international-level) female athletes (age 23 ± 4 y) completed a self-administered questionnaire assessing OC-regimen habits and reasons for manipulation of menstruation. RESULTS: The majority (74%) of OC users reported having deliberately manipulated menstruation at least once during the previous year, with 29% reporting having done so at least 4 times. Prevalence of menstrual manipulation (at least once in the previous year) was not different between competitive athletes, subelite recreationally active women, and recreationally active women (77% vs 74% vs 72%; P > .05). The most cited reasons for manipulating menstruation were special events or holidays (rated by 75% as important/very important), convenience (54%), and sport competition (54%). CONCLUSIONS: Menstrual manipulation through extended OC regimens is common practice in recreationally and competitively active young women, for a range of reasons relating to convenience that are not limited to physical activity. This strategy may help reduce hormone-related barriers to exercise participation, thereby positively affecting participation and performance.


Subject(s)
Contraceptives, Oral/administration & dosage , Exercise/physiology , Menstruation/drug effects , Sports/physiology , Competitive Behavior/physiology , Drug Administration Schedule , Female , Humans , Surveys and Questionnaires , Young Adult
17.
J Sci Med Sport ; 20(11): 965-969, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28684053

ABSTRACT

OBJECTIVES: Fluctuating endogenous and exogenous ovarian hormones may influence exercise parameters; yet control and verification of ovarian hormone status is rarely reported and limits current exercise science and sports medicine research. The purpose of this study was to determine the effectiveness of an individualised three-step method in identifying the mid-luteal or high hormone phase in endogenous and exogenous hormone cycles in recreationally-active women and determine hormone and demographic characteristics associated with unsuccessful classification. DESIGN: Cross-sectional study design. METHODS: Fifty-four recreationally-active women who were either long-term oral contraceptive users (n=28) or experiencing regular natural menstrual cycles (n=26) completed step-wise menstrual mapping, urinary ovulation prediction testing and venous blood sampling for serum/plasma hormone analysis on two days, 6-12days after positive ovulation prediction to verify ovarian hormone concentrations. RESULTS: Mid-luteal phase was successfully verified in 100% of oral contraceptive users, and 70% of naturally-menstruating women. Thirty percent of participants were classified as luteal phase deficient; when excluded, the success of the method was 89%. Lower age, body fat and longer menstrual cycles were significantly associated with luteal phase deficiency. CONCLUSIONS: A step-wise method including menstrual cycle mapping, urinary ovulation prediction and serum/plasma hormone measurement was effective at verifying ovarian hormone status. Additional consideration of age, body fat and cycle length enhanced identification of luteal phase deficiency in physically-active women. These findings enable the development of stricter exclusion criteria for female participants in research studies and minimise the influence of ovarian hormone variations within sports and exercise science and medicine research.


Subject(s)
Contraceptives, Oral/blood , Luteal Phase/blood , Menstruation Disturbances/diagnosis , Adiposity , Adult , Age Factors , Biomarkers/blood , Contraceptives, Oral/administration & dosage , Cross-Sectional Studies , Estradiol/blood , Exercise/physiology , Female , Humans , Menstruation Disturbances/etiology , Menstruation Disturbances/metabolism , Ovulation/urine , Progesterone/blood , Time Factors , Young Adult
18.
Med Sci Sports Exerc ; 49(4): 717-727, 2017 04.
Article in English | MEDLINE | ID: mdl-27898641

ABSTRACT

PURPOSE: Oral contraceptive (OC) use reduces peak aerobic capacity (V˙O2peak); however, whether it also influences adaptations to training has yet to be determined. This study aimed to examine the influence of OC use on peak performance (peak power output [PPO]) and physiological adaptations (V˙O2peak and peak cardiac output [Q˙peak]) after sprint interval training (SIT) in recreationally active women. METHODS: Women taking an OC (n = 25) or experiencing natural regular menstrual cycles (MC; n = 16) completed an incremental exercise test to assess V˙O2peak, PPO, and Q˙peak before, immediately after, and 4 wk after 12 sessions of SIT. The SIT consisted ten 1-min efforts at 100% to 120% PPO in a 1:2 work-rest ratio. RESULTS: Though V˙O2peak increased in both groups after SIT (both P < 0.001), the MC group showed greater improvement (OC, +8.5%; MC, +13.0%; P = 0.010). Similarly, Q˙peak increased in both groups, with greater improvement in the MC group (OC, +4.0%; MC, +16.1%; P = 0.013). PPO increased in both groups (OC, +13.1%; MC, +13.8%; NS). All parameters decreased 4 wk after SIT cessation, but remained elevated from pretraining levels; the OC group showed more sustained training effects in V˙O2peak (OC, -4.0%; MC, -7.7%; P = 0.010). CONCLUSION: SIT improved peak exercise responses in recreationally active women. However, OC use dampened V˙O2peak and Q˙peak adaptation. A follow-up period indicated that OC users had spared V˙O2peak adaptations, suggesting that OC use may influence the time course of physiological training adaptations. Therefore, OC use should be verified, controlled for, and considered when interpreting physiological adaptations to exercise training in women.


Subject(s)
Adaptation, Physiological , Athletic Performance/physiology , Contraceptives, Oral/administration & dosage , High-Intensity Interval Training , Adult , Cardiac Output/physiology , Female , Humans , Menstruation/physiology , Oxygen Consumption/physiology , Perception , Physical Exertion/physiology , Respiration , Stroke Volume/physiology , Young Adult
19.
BMJ Open Diabetes Res Care ; 4(1): e000235, 2016.
Article in English | MEDLINE | ID: mdl-27486520

ABSTRACT

OBJECTIVE: This study examined whether the presence of peripheral sensory neuropathy or cardiac autonomic deficits is associated with postocclusive reactive hyperemia (reflective of microvascular function) in the diabetic foot. RESEARCH DESIGN AND METHODS: 99 participants with type 2 diabetes were recruited into this cross-sectional study. The presence of peripheral sensory neuropathy was determined with standard clinical tests and cardiac autonomic function was assessed with heart rate variation testing. Postocclusive reactive hyperemia was measured with laser Doppler in the hallux. Multiple hierarchical regression was performed to examine relationships between neuropathy and the peak perfusion following occlusion and the time to reach this peak. RESULTS: Peripheral sensory neuropathy predicted 22% of the variance in time to peak following occlusion (p<0.05), being associated with a slower time to peak but was not associated with the magnitude of the peak. Heart rate variation was not associated with the postocclusive reactive hyperemia response. CONCLUSIONS: This study found an association between the presence of peripheral sensory neuropathy in people with diabetes and altered microvascular reactivity in the lower limb.

20.
J Diabetes Complications ; 30(6): 1087-92, 2016 08.
Article in English | MEDLINE | ID: mdl-27156167

ABSTRACT

AIMS: Neuropathies are common complications of diabetes and are proposed to influence peripheral bone, principally via an altered vascular supply. This study aimed to determine the relationship between subtypes of neuropathy and vascular reactivity on foot bone density in people with diabetes. METHODS: A case-control observational design was utilised with two groups: those with diabetic peripheral large fibre neuropathy (n=23) and a control group with diabetes but without neuropathy (n=23). Bone density in 12 foot bones was determined with computed tomography scanning. Additionally, post-occlusive reactive hyperemia, presence of small fibre neuropathy and heart rate variability were determined. T-tests and hierarchical regression were used to examine the relationships among the variables. RESULTS: No difference in foot bone density was found between those with and those without large fibre neuropathy. Furthermore, no association between heart rate variability or reactive hyperemia and bone density was found. Small fibre neuropathy was associated with increased cuboid trabecular bone density (p=0.006) with its presence predictive of 14% of the variance. CONCLUSIONS: This study found no clear association between presence of diabetic neuropathies and foot bone density. Furthermore, vascular reactivity appears to have no impact on bone density.


Subject(s)
Bone Density , Diabetic Neuropathies/pathology , Foot/diagnostic imaging , Aged , Case-Control Studies , Female , Heart Rate , Humans , Male , Middle Aged , Tomography, X-Ray Computed
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