Is It Necessary to Adapt Training According to the Menstrual Cycle? Influence of Contraception and Physical Fitness Variables.

(1) Background: The influence of the menstrual cycle on physical fitness in athletes is controversial in the scientific literature. There is a marked fluctuation of sex hormones at three key points of the menstrual cycle, where estrogen and progesterone vary significantly. Hormonal contraception induces hormonal levels different from the natural menstrual cycle, requiring specific study in relation to physical fitness. (2) Method: Women aged 18 to 40 years with regular natural menstrual cycles and women using hormonal contraception were recruited, creating two study groups. All participants needed to be athletes classified as level II-III, based on training volume/physical activity metrics, among other variables. To assess their physical fitness, cardiorespiratory fitness (measured by V˙O2max), high-speed strength, hand grip strength, and flexibility were evaluated. Blood samples were taken to determine the menstrual cycle phase through analysis of sex hormone levels. Additionally, urine tests for ovulation detection were performed for the natural menstrual cycle group. Neurosensory stimulation tests were incorporated to measure sensory thresholds and pain thresholds in each phase. Body composition in each phase and its relationship with the other variables were also taken into account. (3) Results: Athletes in the natural cycling group showed differences in V˙O2max (mL·kg-1·min-1) (phase I = 41.75 vs. phase II = 43.85 and (p = 0.004) and phase I vs. phase III = 43.25 mL·kg-1·min-1 (p = 0.043)), as well as in body weight (phase I = 63.23 vs. phase III = 62.48 kg; p = 0.006), first pain threshold (phase I = 1.34 vs. phase II = 1.69 (p = 0.027) and phase III = 1.59 mA (p = 0.011)), and sensitive threshold (phase I = 0.64 vs. phase II = 0.76 mA (p = 0.017)). The pain threshold was found to be an important covariate in relation to V˙O2max, explaining 31.9% of the variance in phase I (p = 0.006). These findings were not observed between the two phases of contraceptive cycling. (4) Conclusion: The natural menstrual cycle will cause significant changes in the physical fitness of athletes. The use of hormonal contraception is not innocuous. Women with natural cycles show an increase in cardiorespiratory fitness in phases II and III, which is a factor to be considered in relation to training level and workload.

Breast Cancer Patients' Experiences with Online Group-Based Physical Exercise in a COVID-19 Context: A Focus Group Study.

In patients with breast cancer, physical exercise reduces the toxicity of treatment; however, this physical exercise must meet a set of criteria, such as being guided by knowledgeable instructors. Thus, the aim of this study was to explore the perceptions of female breast cancer patients regarding the impact of an online physical exercise programme in the context of the COVID-19 pandemic. Nineteen female breast cancer patients participated in four focus group interviews as part of a qualitative study using a thematic analysis between December 2020 and May 2021. Three major themes emerged: "Experiences and perceptions of online physical exercise with breast cancer"; "Incorporating exercise-based activity for cancer-related side effects"; and "Increasing self-esteem and empowerment". Online, live-streamed, and supervised group activities help breast cancer patients engage and prevent the recurrence of cancer-related side effects, as well as to control COVID-19-related fear and provide an alternative to promote mental health-related quality of life.

Recovery of Inflammation, Cardiac, and Muscle Damage Biomarkers After Running a Marathon.

ABSTRACT: Bernat-Adell, MD, Collado-Boira, EJ, Moles-Julio, P, Panizo-González, N, Martínez-Navarro, I, Hernando-Fuster, B, and Hernando-Domingo, C. Recovery of inflammation, cardiac and muscle damage biomarkers after running a marathon. J Strength Cond Res 35(3): 626-632, 2021-Physical endurance sports conditions the increase of blood biomarkers responsible for the acute inflammatory response. The purpose of this study was to observe the impact of intense physical exercise on these biomarkers and detect their recovery pattern. This is an experimental study of repeated measures (pre-post marathon). The biomarkers lactate dehydrogenase (LDH), creatine kinase (CK), high-sensitivity troponin T (hs-TNT), and C-reactive protein (CRP) were analyzed in a total of 86 runners, 24 hours before the marathon, immediately after finishing the race and at 24, 48, 96, and 144 postrace hours. The comparative analyses were performed using the Friedman and Wilcoxon tests. The correlations between dependent and independent variables were analyzed using Spearman correlations. The data were processed through the IBM SPSS package, version 23. Significant value was p ≤ 0.05. The LDH increased and showed significant differences (p ≤ 0.001) for all times, compared with the initial LDH value, normalizing after 192 hours (p = 0.667) (effect size [ES], r = 0.807). The CK increased and showed significant differences (p ≤ 0.001) (ES, r = 0.975) up to 96 hours afterward, normalizing after 144 hours. The hs-TNT presented an increase and showed significant differences (p ≤ 0.001) between the pre-post race times, 24 and 48 hours, normalizing after 96 hours, although it showed a new significant value at 192 hours (p ≤ 0.001) (ES, r = 0.519). The CRP increased and showed significant differences (p ≤ 0.001) between the pre-post race times, at 24, 48, 96, 144, and 192 hours after race. The recovery after alterations produced by the marathon varies according to the biomarker. Blood levels of biomarkers decrease with longer race times. Greater energy expenditure increases the blood levels of LDH, CK, and hs-TNT.

Quick Recovery of Renal Alterations and Inflammatory Activation after a Marathon.

PURPOSE: We evaluated the incidence of acute kidney injury in a cohort of marathon participants. METHODS: We conducted a prospective observational study focused on evaluating the incidence of kidney damage after a marathon, and its evolution in the first 48 h after the marathon in 88 runners who completed the Valencia Marathon. RESULTS: From the 88 participants, 42 (48.28%) presented with acute kidney injury, mainly grade 1 (95.20%). Microscopic haematuria was observed in 29 runners (33%). Levels of interleukin 6, leukocytes, and neutrophils were markedly increased at the marathon's finish line. CONCLUSIONS: Our results confirmed that there are slight transient changes in glomerular filtration rate and inflammatory activation after a marathon.