Summary Wooden breast (WB) abnormalities of broilers compromise the quality of fresh and processed meat. Yet, no standardised classification method for evaluating WB currently exists. We here provide a novel classification method to determine the severity of WB by palpation. Data were evaluated by one‐way anova. The classification method proved robust and reliable to classify broiler filets into three distinct categories (no, moderate and severe WB). This was supported by histological findings, demonstrating less muscle tissue in WB‐affected samples. Moreover, moisture content, resistance to compression, mobile water fraction, drip loss and cooking loss, as well as intramuscular and surface pH also increased with WB. Using the classification method, we demonstrated that severe WB increased the diversity of the endogenous microflora and promoted growth of Enterobacteriaceae. In conclusion, the presented classification method correlates with known meat quality traits and will be a valuable tool for future studies on WB.

Introduction: The majority of young women use oral contraceptives (OCs). Use of OCs has been associated with lower myofibrillar protein and tendon collagen synthesis rates, but it is unknown whether OCs will limit the adaptive response of myotendinous tissue to resistance training. Design and Methods: Fourteen healthy untrained young regular OC users (24 ± 1 years, fat% 32 ± 1, 35 ± 2 ml⋅min -1 ⋅kg -1 ) and 14 NOC users (non-OC, controls) (24 ± 1 years, fat% 32 ± 2, 34 ± 2 ml⋅min -1 ⋅kg -1 ) performed a 10-week supervised lower extremity progressive resistance training program. Before and after the intervention biopsies from the vastus lateralis muscle and the patellar tendon were obtained. Muscle (quadriceps) and tendon cross-sectional area (CSA) was determined by magnetic resonance imaging (MRI) scans, and muscle fiber CSA was determined by histochemistry. Maximal isometric knee extension strength was assessed by dynamometry while 1 repetition maximum (RM) was determined during knee extension. Results: Training enhanced CSA in both muscle ( p < 0.001) and tendon ( p < 0.01). A trend toward a greater increase in muscle CSA was observed for OC (11%) compared to NOC (8%) (interaction p = 0.06). Analysis of mean muscle fiber type CSA showed a trend toward an increase in type II muscle fiber area in both groups ( p = 0.11, interaction p = 0.98), whereas type I muscle fiber CSA increased in the OC group ( n = 9, 3821 ± 197 to 4490 ± 313 mm 2 , p < 0.05), but not in NOC ( n = 7, 4020 ± 348 to 3777 ± 354 mm 2 , p = 0.40) (interaction p < 0.05). Post hoc analyses indicated that the effect of OCs on muscle mass increase was induced by the OC-users ( n = 7), who used OCs containing 30 μg ethinyl estradiol (EE), whereas the response in users taking OCs with 20 μg EE ( n = 7) did not differ from NOC. Both the OC and NOC group experienced an increase in maximal knee strength ( p < 0.001) and 1RM leg extension ( p < 0.001) after the training period with no difference between groups. Conclusion: Use of OCs during a 10-week supervised progressive resistance training program was associated with a trend toward a greater increase in muscle mass and a significantly greater increase in type I muscle fiber area compared to controls. Yet, use of OCs did not influence the overall increase in muscle strength related to training.

Objective: To identify the prevalence of hormonal contraceptive (HC) use, menstrual cycle disturbances, and self-perceived physical and emotional symptoms related to the menstrual cycle/pill cycle in elite female athletes. Methods: One hundred eighty-six Danish elite female athletes completed an online questionnaire to assess menstrual status and history, use of HCs, and self-perceived physical and emotional symptoms related to the menstrual cycle or HC use. Results: Fifty-seven percent of elite female athletes in Denmark use HC, with 74% using combined HCs and 26% using progestin only. Sixty percent of oral contraceptive users reported having manipulated their menstrual cycle by continuous oral contraceptive use. Forty-nine percent of non-HC users had a regular menstrual cycle, while 51% experienced menstrual disturbances, with 1 athlete being primary amenorrheic and 13 athletes having secondary amenorrhea. Menstrual disturbances were experienced by a larger proportion of endurance athletes (69%) compared with athletes performing power and technical disciplines. In endurance athletes amenorrhea was associated with a higher cardiovascular training volume (P < .001). Negative symptoms related to the menstrual/pill cycle were reported by both HC and non-HC users, whereas positive physical symptoms were experienced more often among the non-HC (14%) versus HC users (2%) (P < .01). Notably, 13% of the athletes reported that negative symptoms sometimes/always caused them to not participate in or complete the scheduled training. Conclusion: HC use is common among elite athletes, and continuation of HC is used to manipulate the menstrual cycle in relation to sport competitions. HC use does not abolish dysmenorrhea, but it may reduce emotional-related side effects. Menstrual disturbances are frequent in endurance athletes and are associated with cardiovascular training volume.

ContextWomen show an accelerated loss of muscle mass around menopause, possibly related to the decline in estrogen. Furthermore, the anabolic response to resistance exercise seems to be hampered in postmenopausal women.ObjectiveWe aimed to test the hypothesis that transdermal estrogen therapy (ET) amplifies the skeletal muscle response to resistance training in early postmenopausal women.DesignA double-blinded randomized controlled study.SettingDepartment of Public Health, Aarhus University, Denmark.ParticipantsThirty-one healthy, untrained postmenopausal women no more than 5 years past menopause.Intervention(s)Supervised resistance training with placebo (PLC, n = 16) or transdermal ET (n = 15) for 12 weeks.Main Outcome Measure(s)The primary outcome parameter was a cross-sectional area of quadriceps femoris measured by magnetic resonance imaging, and secondary parameters were fat-free mass (dual-energy X-ray absorptiometry), muscle strength, and functional tests.ResultsThe increase in muscle cross-sectional area was significantly greater in the ET group (7.9%) compared with the PLC group (3.9%) (p &lt; 0.05). Similarly, the increase in whole-body fat-free mass was greater in the ET group (5.5%) than in the PLC group (2.9%) (p &lt; 0.05). Handgrip strength increased in ET (p &lt; 0.05) but did not change in the PLC group. Muscle strength parameters, jumping height, and finger strength were all improved after the training period with no difference between groups.ConclusionThe use of transdermal ET enhanced the increase in muscle mass in response to 12 weeks of progressive resistance training in early postmenopausal women.

Aim: Previous reports suggest that low-load muscle exercise performed under blood flow restriction (BFR) may lead to endurance adaptations. However, only few and conflicting results exist on the magnitude and timing of microvascular adaptations, overall indicating a lack of angiogenesis with BFR training. The present study, therefore, aimed to examine the effect of short-term high-frequency BFR training on human skeletal muscle vascularization. Methods: Participants completed 3 weeks of high-frequency (one to two daily sessions) training consisting of either BFR exercise [(BFRE) n = 10, 22.8 ± 2.3 years; 20% one-repetition maximum (1RM), 100 mmHg] performed to concentric failure or work-matched free-flow exercise [(CON) n = 8, 21.9 ± 3.0 years; 20% 1RM]. Muscle biopsies [vastus lateralis (VL)] were obtained at baseline, 8 days into the intervention, and 3 and 10 days after cessation of the intervention to examine capillary and perivascular adaptations, as well as angiogenesis-related protein signaling and gene expression. Results: Capillary per myofiber and capillary area (CA) increased 21-24 and 25-34%, respectively, in response to BFRE (P < 0.05-0.01), while capillary density (CD) remained unchanged. Overall, these adaptations led to a consistent elevation (15-16%) in the capillary-to-muscle area ratio following BFRE (P < 0.05-0.01). In addition, evaluation of perivascular properties indicated thickening of the perivascular basal membrane following BFRE. No or only minor changes were observed in CON.