Effects of follicular versus luteal phase-based strength training in young women

Hormonal variations during the menstrual cycle (MC) may influence trainability of strength. We investigated the effects of a follicular phase-based strength training (FT) on muscle strength, muscle volume and microscopic parameters, comparing it to a luteal phase-based training (LT). Eumenorrheic women without oral contraception (OC) (N = 20, age: 25.9 ± 4.5 yr, height: 164.2 ± 5.5 cm, weight: 60.6 ± 7.8 kg) completed strength training on a leg press for three MC, and 9 of them participated in muscle biopsies. One leg had eight training sessions in the follicular phases (FP) and only two sessions in the luteal phases (LP) for follicular phase-based training (FT), while the other leg had eight training sessions in LP and only two sessions in FP for luteal phase-based training (LT). Estradiol (E2), progesterone (P4), total testosterone (T), free testosterone (free T) and DHEA-s were analysed once during FP (around day 11) and once during LP (around day 25). Maximum isometric force (Fmax), muscle diameter (Mdm), muscle fibre composition (No), fibre diameter (Fdm) and cell nuclei-to-fibre ratio (N/F) were analysed before and after the training intervention. T and free T were higher in FP compared to LP prior to the training intervention (P < 0.05). The increase in Fmax after FT was higher compared to LT (P <0.05). FT also showed a higher increase in Mdm than LT (P < 0.05). Moreover, we found significant increases in Fdm of fibre type ΙΙ and in N/F only after FT; however, there was no significant difference from LT. With regard to change in fibre composition, no differences were observed between FT and LT. FT showed a higher gain in muscle strength and muscle diameter than LT. As a result, we recommend that eumenorrheic females without OC should base the periodization of their strength training on their individual MC

Time-motion analysis in women’s team handball: importance of aerobic performance

Women’s handball is a sport, which has seen an accelerated development over the last decade. Data on movement patterns in combination with physiological demands are nearly nonexistent in the literature. The aim of this study was twofold: first, to analyze the horizontal movement pattern, including the sprint acceleration profiles, of individual female elite handball players and the corresponding heart rates (HRs) during a match and secondly to determine underlying correlations with individual aerobic performance. Players from one German First League team (n = 11) and the Norwegian National Team (n = 14) were studied during one match using the Sagit system for movement analysis and Polar HR monitoring for analysis of physiological demands. Mean HR during the match was 86 % of maximum HR (HRmax). With the exception of the goalkeepers (GKs, 78 % of HRmax), no position-specific differences could be detected. Total distance covered during the match was 4614 m (2066 m in GKs and 5251 m in field players (FPs)). Total distance consisted of 9.2 % sprinting, 26.7 % fast running, 28.8 % slow running, and 35.5 % walking. Mean velocity varied between 1.9 km/h (0.52 m/s) (GKs) and 4.2 km/h (1.17 m/s) (FPs, no position effect). Field players with a higher level of maximum oxygen uptake (V̇O2max) executed run activities with a higher velocity but comparable percentage of HRmax as compared to players with lower aerobic performance, independent of FP position. Acceleration profile depended on aerobic performance and the field player’s position. In conclusion, a high V̇O2max appears to be important in top-level international women’s handball. Sprint and endurance training should be conducted according to the specific demands of the player’s position

Strength training and the menstrual cycle

Hormonelle Veränderungen während des Menstruationszyklus können die Trainierbarkeit der Kraft beeinflussen. Orale Kontrazeption (OC) verändert das Profil dieser Hormone. Aus diesem Grund untersuchten wir die Wirkungen eines Follikelphase (FP)-betontem Krafttrainings (FT) im Vergleich zu Lutealphase (LP)-betontem Krafttraining (LT) bei Frauen, die OC einnahmen (OC users), u. jenen, die keine OC einnahmen (non-OC users). 20 non-OC users und 17 OC users absolvierten ein einbeiniges Krafttraining für 12 Wochen. Sie trainierten ein Bein in FP, das andere Bein in LP. Hormonprofile, F$_{max}$, Mdm und Muskelzellen wurden vor und nach der Trainingsintervention analysiert. Anabole Hormone waren signifikant höher bei non-OC users im Vergleich zu OC users. Die Steigerung von F$_{max}$ war bei non-OC users nach FT höher als nach LT (p<0,05). Bei OC users gab es diesbezüglich keinen Unterschied. Die Steigerung von F$_{max}$ nach LT war am geringsten verglichen mit LT bei non-OC users somit FT und LT bei OC users.Hormonal variations during the menstrual cycle may influence trainability of strength. However, oral contraception (OC) alters the profile of these hormones. For this reason, we investigated the effects of follicular phase (FP)-based strength training (FT) compared to luteal phase (LP)-based strength training (LT) in women who took OC (OC users), and in women who did not take OC (non-OC users). 20 non-OC users and 17 OC users completed one-leg strength training for 12 weeks. They trained one leg mainly in FP and the other leg mainly in LP. Hormone profiles, F$_{max}$, Mdm and muscle cells were analyzed before and after the training intervention. Anabolic hormones were significantly higher in non-OC users compared to OC users. Increase of F$_{max}$ after FT was higher than after LT in non-OC users (p<0.05). In OC users, we did not find any differences between FT and LT. Increase of F$_{max}$ after LT in non-OC users was the lowest compared to FT in non-OC users compared to FT and LT in OC users

Identification of Risk Factors for Locoregional Recurrence in Breast Cancer Patients with Nodal Stage N0 and N1: Who Could Benefit from Post-Mastectomy Radiotherapy?

INTRODUCTION:The locoregional recurrence (LRR) rate was reported as high as approximately 20% in stage I-II breast cancer following mastectomy. To investigate the risk factors for LRR in pT1-2N0-1 breast cancer patients treated with mastectomy but not radiation, and to define a subgroup of patients at high risk of LRR who may benefit from postmastectomy radiotherapy (PMRT). METHODS AND MATERIALS:In total, 390 patients with pT1-2N0M0 (n = 307) and pT1-2N1M0 (n = 83) breast cancer who underwent total mastectomy without adjuvant radiotherapy from 2002 to 2011 were enrolled in the study. RESULTS:After a median follow-up period of 5.6 years (range, 0.6-11.3 years), 21 patients had 18 systemic relapses and 12 LRRs including six in the chest wall and eight in the regional nodal area. The 5-year LRR-free survival (LRRFS) rates were 97.0% in pN0, 98.8% in pN1, and 97.4% in all patients. Multivariate analysis revealed that age < 50 years (Hazard Ratio, 11.4; p = 0.01) and no adjuvant chemotherapy (Hazard Ratio, 10.2; p = 0.04) were independent risk factors for LRR in pN0 patients. Using these factors, the 5-year LRRFS rates were 100% without any risk factors, 96.4% with one risk factor, and 86.7% with two risk factors. In pN1 patients, multivariate analysis revealed that having a hormone receptor negative tumor (Hazard Ratio, 18.3; p = 0.03) was the only independent risk factor for LRR. The 5-year LRRFS rates were 100.0% for luminal type, and 92.3% for non-luminal type cancer. CONCLUSION:Patients with pT1-2N0-1 breast cancer who underwent total mastectomy without PMRT could be stratified by nodal stage and risk factors for LRR. PMRT may have of value for node negative patients aged less than 50 years and who are not treated with adjuvant chemotherapy, and for non-luminal type patients with one to three positive nodes

Effects of oral contraceptive use on muscle strength, muscle thickness, and fiber size and composition in young women undergoing 12 weeks of strength training

$\bf Background:$ It is suspected that hormonal fluctuations during menstruation may cause different responses to strength training in women who use oral contraceptives (OC) versus those who do not. However, previous studies that investigated the existence of such differences produced conflicting results. In this study, we hypothesized that OC use has no effect on muscle strength and hypertrophy among women undergoing strength training. Thus, we compared the differences in muscle strength and thickness among women who used OCs and those who did not. $\bf Methods:$ We investigated the influence of OC use on muscle strength $(F_{max})$, muscle thickness (Mtk), type 1-to-type 2 muscle fiber (NO) ratio, muscle fiber thickness (MFT), and nuclear-to-fiber (N/F) ratio. Seventy-four healthy young women (including 34 who used OCs and 40 who did not) underwent 12 weeks of submaximal strength training, after which $F_{max}$ was evaluated using a leg-press machine with a combined force and load cell, while Mtk was measured using real-time ultrasonography. Moreover, the NO ratio, MFT, and N/F ratio were evaluated using muscle needle biopsies. $\bf Results:$ Participants in the non-OC and OC groups experienced increases in $F_{max}$ (+ 23.30 $\pm$ 10.82 kg and + 28.02 $\pm$ 11.50 kg respectively, $\it p$ = 0.073), Mtk (+ 0.48 $\pm$ 0.47 $cm^{2}$ and + 0.50 $\pm$ 0.44 $cm^{2}$ respectively, $\it p$ = 0.888), $F_{max}$/Mtk (+ 2.78 $\pm$ 1.93 kg/cm2 and + 3.32 $\pm$ 2.37 kg/$cm^{2}$ respectively, $\it p$ = 0.285), NO ratio (type 2 fibers: + 1.86 $\pm$ 6.49% and − 4.17 $\pm$ 9.48% respectively, $\it p$ = 0.169), MFT (type 2 fibers: + 7.15 $\pm$ 7.50 $\mu$m and + 4.07 $\pm$ 9.30 $\mu$m respectively, $\it p$ = 0.435), and N/F ratio (+ 0.61 $\pm$ 1.02 and + 0.15 $\pm$ 0.97 respectively, $\it p$ = 0.866) after training. There were no significant differences between the non-OC and OC groups in any of these parameters ($\it p$ > 0.05). $\bf Conclusions:$ The effects of 12 weeks of strength training on Fmax, muscle thickness, muscle fiber size, and composition were similar in young women irrespective of their OC use

Phenolic condensation and facilitation of fluorescent carbon dot formation: a mechanism study

Fluorescent carbon dots have received considerable attention as a result of their accessibility and potential applications. Although several prior studies have demonstrated that nearly any organic compound can be converted into carbon dots by chemical carbonization processes, mechanisms explaining the formation of carbon dots still remain unclear. Herein, we propose a seed-growth mechanism of carbon dot formation facilitated by ferulic acid, a widespread and naturally occurring phenolic compound in the seeds of Ocimum basilicum (basil). Ferulic acid triggers the local condensation of polysaccharide chains and forms catalytic core regions resulting in nanoscale carbonization. Our study indicates that carbon dots generated from natural sources might share the similar mechanism of phenolic compound mediated nanoscale condensation followed by core carbonization

Reactive Oxygen Species-Responsive Miktoarm Amphiphile for Triggered Intracellular Release of Anti-Cancer Therapeutics

Reactive oxygen species (ROS)-responsive nanocarriers have received considerable research attention as putative cancer treatments because their tumor cell targets have high ROS levels. Here, we synthesized a miktoarm amphiphile of dithioketal-linked ditocopheryl polyethylene glycol (DTTP) by introducing ROS-cleavable thioketal groups as linkers between the hydrophilic and hydrophobic moieties. We used the product as a carrier for the controlled release of doxorubicin (DOX). DTTP has a critical micelle concentration (CMC) as low as 1.55 μg/mL (4.18 × 10−4 mM), encapsulation efficiency as high as 43.6 ± 0.23% and 14.6 nm particle size. The DTTP micelles were very responsive to ROS and released their DOX loads in a controlled manner. The tocopheryl derivates linked to DTTP generated ROS and added to the intracellular ROS in MCF-7 cancer cells but not in HEK-293 normal cells. In vitro cytotoxicity assays demonstrated that DOX-encapsulated DTTP micelles displayed strong antitumor activity but only slightly increased apoptosis in normal cells. This ROS-triggered, self-accelerating drug release device has high therapeutic efficacy and could be a practical new strategy for the clinical application of ROS-responsive drug delivery systems