Aminoacidemia after ingestion of protein hydrolysate produced from poultry carcasses: A comparison against whey protein in a randomized, double-blinded cross-over study in healthy young and old individuals

This study investigated the aminoacidemia after ingestion of a poultry protein hydrolysate (PPH) and whey protein in healthy young and old participants. Protein-drinks were also digested using the INFOGEST static in vitro digestion model to simulate gastrointestinal changes in young and old adults. In fasted state, 10 young (20-40y) and 10 old (70-80y) ingested PPH or whey as a 20 g protein-drink and blood samples were collected. Plasma leucine concentration increased more when ingesting whey than PPH (young 62 ± 27 vs. 48 ± 27%, old 94 ± 57 vs. 66 ± 26%) but the peak concentration was reached faster after drinking PPH (p < 0.05). The in vitro digestion of PPH was consistent with the observed changes in plasma amino acid concentrations, but whey digestibility was lower under ageing conditions. These results show that PPH is rapidly digested and absorbed due to the hydrolysis into short peptide chains, and that healthy elderly have similar absorption as younger individuals.Aminoacidemia after ingestion of protein hydrolysate produced from poultry carcasses: A comparison against whey protein in a randomized, double-blinded cross-over study in healthy young and old individualspublishedVersio

Criteria for the determination of maximal oxygen uptake in patients newly diagnosed with cancer : Baseline data from the randomized controlled trial of physical training and cancer (Phys-Can)

Introduction: Maximal oxygen uptake (VO2max) is a measure of cardiorespiratory fitness often used to monitor changes in fitness during and after treatment in cancer patients. There is, however, limited knowledge in how criteria verifying VO2max work for patients newly diagnosed with cancer. Therefore, the aim of this study was to describe the prevalence of fulfillment of typical criteria verifying VO2max and to investigate the associations between the criteria and the test leader’s evaluation whether a test was performed “to exhaustion”. An additional aim was to establish new cut-points within the associated criteria. Methods: From the Phys-Can randomized controlled trial, 535 patients (59 ±12 years) newly diagnosed with breast (79%), prostate (17%) or colorectal cancer (4%) performed an incremental VO2max test on a treadmill. The test was performed before starting (neo-)adjuvant treatment and an exercise intervention. Fulfillment of different cut-points within typical criteria verifying VO2max was described. The dependent key variables included in the initial bivariate analysis were achievement of a VO2 plateau, peak values for maximal heart rate, respiratory exchange ratio (RER), the patients’ rating of perceived exertion on Borg’s scale 6-20 and peak breathing frequency (fR). A receiver operating characteristic analysis was performed to establish cut-points for variables associated with the test leader’s evaluation. Last, a cross-validation of the cut-points found in the receiver operating characteristic analysis was performed on a comparable sample of cancer patients (n = 80). Results: The criteria RERpeak (<0.001), Borg’s RPE (<0.001) and fR peak (p = 0.018) were associated with the test leader’s evaluation of whether a test was defined as “to exhaustion”. The cut-points that best predicted the test leader’s evaluation were RER ≥ 1.14, RPE ≥ 18 and fR ≥ 40. Maximal heart rate and VO2 plateau was not associated with the test leader’s evaluation. Conclusion: We recommend a focus on RER (in the range between ≥1.1 and ≥1.15) and RPE (≥17 or ≥18) in addition to the test leader’s evaluation. Additionally, a fR peak of ≥40 breaths/min may be a cut-point to help the test leader evaluate the degree of exhaustion. However, more research is needed to verify our findings, and to investigate how these criteria will work within a population that are undergoing or finished with cancer treatment.publishedVersio

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Where Does Blood Flow Restriction Fit in the Toolbox of Athletic Development? A Narrative Review of the Proposed Mechanisms and Potential Applications

Blood flow-restricted exercise is currently used as a low-intensity time-efficient approach to reap many of the benefits of typical high-intensity training. Evidence continues to lend support to the notion that even highly trained individuals, such as athletes, still benefit from this mode of training. Both resistance and endurance exercise may be combined with blood flow restriction to provide a spectrum of adaptations in skeletal muscle, spanning from myofibrillar to mitochondrial adjustments. Such diverse adaptations would benefit both muscular strength and endurance qualities concurrently, which are demanded in athletic performance, most notably in team sports. Moreover, recent work indicates that when traditional high-load resistance training is supplemented with low-load, blood flow-restricted exercise, either in the same session or as a separate training block in a periodised programme, a synergistic and complementary effect on training adaptations may occur. Transient reductions in mechanical loading of tissues afforded by low-load, blood flow-restricted exercise may also serve a purpose during de-loading, tapering or rehabilitation of musculoskeletal injury. This narrative review aims to expand on the current scientific and practical understanding of how blood flow restriction methods may be applied by coaches and practitioners to enhance current athletic development models.publishedVersionPaid open acces

Exploring moderators of the effect of high vs. low-to-moderate Intensity exercise on cardiorespiratory fitness during breast cancer treatment – Analyses of a subsample from the phys-can RCT

Introduction The results from the physical training and cancer randomized controlled trial (Phys-Can RCT) indicate that high intensity (HI) strength and endurance training during (neo-)adjuvant cancer treatment is more beneficial for cardiorespiratory fitness (CRF, measured as peak oxygen uptake [VO2peak]) than low-to-moderate intensity (LMI) exercise. Adherence to the exercise intervention and demographic or clinical characteristics of patients with breast cancer undergoing adjuvant treatment may moderate the exercise intervention effect on VO2peak. In this study, the objective was to investigate whether baseline values of VO2peak, body mass index (BMI), time spent in moderate- to vigorous-intensity physical activity (MVPA), physical fatigue, age, chemotherapy treatment, and the adherence to the endurance training moderated the effect of HI vs. LMI exercise on VO2peak. Materials and Methods We used data collected from a subsample from the Phys-Can RCT; women who were diagnosed with breast cancer and had a valid baseline and post-intervention VO2peak test were included (n = 255). The exercise interventions from the RCT included strength and endurance training at either LMI, which was continuous endurance training at 40 – 50 % of heart rate reserve (HRR), or at HI, which was interval training at 80–90% of HRR, with similar exercise volume in the two groups. Linear regression analyses were used to investigate moderating effects using a significance level of p \u3c 0.10. Statistically significant interactions were examined further using the Johnson–Neyman (J-N) technique and regions of significance (for continuous variables) or box plots with adjusted means of post-intervention VO2peak (for binary variables). Results Age, as a continuous variable, and adherence, dichotomized into \u3c or \u3e 58% based on median, moderated the effect of HI vs. LMI on CRF (B = −0.08, 95% CI [−0.16, 0.01], pinteraction = 0.06, and B = 1.63, 95% CI [−0.12, 3.38], pinteraction = 0.07, respectively). The J-N technique and regions of significance indicated that the intervention effect (HI vs. LMI) was positive and statistically significant in participants aged 61 years or older. Baseline measurement of CRF, MVPA, BMI, physical fatigue, and chemotherapy treatment did not significantly moderate the intervention effect on CRF. Conclusion Women with breast cancer who are older and who have higher adherence to the exercise regimen may have larger effects of HI exercise during (neo-)adjuvant cancer treatment on CRF

Effectiveness of a resistance training program on physical function, muscle strength, and body composition in community-dwelling older adults receiving home care: A cluster-randomized controlled trial

Background: Aging is associated with reduced muscle mass and strength leading to impaired physical function. Resistance training programs incorporated into older adults’ real-life settings may have the potential to counteract these changes. We evaluated the effectiveness of 8 months resistance training using easily available, low cost equipment compared to physical activity counselling on physical function, muscle strength, and body composition in community-dwelling older adults receiving home care. Methods: This open label, two-armed, parallel group, cluster randomized trial recruited older adults above 70 years (median age 86.0 (Interquartile range 80–90) years) receiving home care. Participants were randomized at cluster level to the resistance training group (RTG) or the control group (CG). The RTG trained twice a week while the CG were informed about the national recommendations for physical activity and received a motivational talk every 6th week. Outcomes were assessed at participant level at baseline, after four, and 8 months and included tests of physical function (chair rise, 8 ft-up-and-go, preferred- and maximal gait speed, and stair climb), maximal strength, rate of force development, and body composition. Results: Twelve clusters were allocated to RTG (7 clusters, 60 participants) or CG (5 clusters, 44 participants). The number of participants analyzed was 56–64 (6–7 clusters) in RTG and 20–42 (5 clusters) in CG. After 8 months, multilevel linear mixed models showed that RTG improved in all tests of physical function and maximal leg strength (9–24%, p = 0.01–0.03) compared to CG. No effects were seen for rate of force development or body composition. Conclusion: This study show that resistance training using easily available, low cost equipment is more effective than physical activity counselling for improving physical function and maximal strength in community-dwelling older adults receiving home care.publishedVersio

Sex differences in the physiological response to a demanding military field exercise

Purpose To investigate sex differences in the effect of a military field exercise on physical performance, body composition, and blood biomarkers. Methods Measurements were done in 23 male and 12 female conscripts before, and 0, 1, 3, 7, and 14 days after a 6‐day military field exercise. Results During the field exercise, body mass decreased more in men (−6.5 ± 1.1 kg) than in women (−2.7 ± 0.7 kg), and muscle mass decreased only in men (−2.7 ± 1.0 kg). Body composition recovered within one week. Performance decreased, with no differences between men and women for countermovement jump (CMJ,‐19 ± 8 vs. −18 ± 11%), medicine ball throw (MBT, −11 ± 7 vs. −11 ± 7%), and an anaerobic performance test (EVAC, −55 ± 22 vs. −47 ± 31%, men and women, respectively). MBT and EVAC performance recovered within two weeks, whereas CMJ performance was still reduced in men (−17 ± 6%) and women (−9 ± 8%) after two weeks recovery, with a larger reduction in men. Both men and women decreased [IGF‐1] (−28 ± 9 vs. −41 ± 8%) and increased [cortisol] (26 ± 26 vs. 66 ± 93%, men and women, respectively) during the exercise. Most biomarkers returned to baseline values within one week. Conclusions Men lost more body mass and muscle mass than women during a field exercise, but these differences did not lead to sex differences in changes in explosive strength and anaerobic performance. However, women recovered explosive strength in the legs faster than men.publishedVersio

Superior Physiological Adaptations After a Microcycle of Short Intervals Versus Long Intervals in Cyclists

Purpose: To compare the effects of a 1-week high-intensity aerobic-training shock microcycle composed of either 5 short-interval sessions (SI; n = 9, 5 series with 12 × 30-s work intervals interspersed with 15-s recovery and 3-min recovery between series) or 5 long-interval sessions (LI; n = 8, 6 series of 5-min work intervals with 2.5-min recovery between series) on indicators of endurance performance in well-trained cyclists. Methods: Before and following 6 days with standardized training loads after the 1-week high-intensity aerobic-training shock microcycle, both groups were tested in physiological determinants of endurance performance. Results: From pretraining to posttraining, SI achieved a larger improvement than LI in maximal oxygen uptake (5.7%; 95% confidence interval, 1.3–10.3; P = .015) and power output at a blood lactate concentration of 4 mmol·L−1 (3.8%; 95% confidence interval, 0.2–7.4; P = .038). There were no group differences in changes of fractional use of maximal oxygen uptake at a workload corresponding to a blood lactate concentration of 4 mmol·L−1, gross efficiency, or the 1-minute peak power output from the maximal-oxygen-uptake test. Conclusion: The SI protocol may induce superior changes in indicators of endurance performance compared with the LI protocol, indicating that SI can be a good strategy during a 1-week high-intensity aerobic-training shock microcycle in well-trained cyclists

Ibuprofen ingestion does not affect markers of post-exercise muscle inflammation

PURPOSE: We investigated if oral ingestion of ibuprofen influenced leucocyte recruitment and infiltration following an acute bout of traditional resistance exercise Methods: Sixteen male subjects were divided into two groups that received the maximum over-the-counter dose of ibuprofen (1200mg d(-1)) or a similarly administered placebo following lower body resistance exercise. Muscle biopsies were taken from m.vastus lateralis and blood serum samples were obtained before and immediately after exercise, and at 3 and 24 h after exercise. Muscle cross-sections were stained with antibodies against neutrophils (CD66b and MPO) and macrophages (CD68). Muscle damage was assessed via creatine kinase and myoglobin in blood serum samples, and muscle soreness was rated on a ten-point pain scale. RESULTS: The resistance exercise protocol stimulated a significant increase in the number of CD66b(+) and MPO(+) cells when measured 3 h post exercise. Serum creatine kinase, myoglobin and subjective muscle soreness all increased post-exercise. Muscle leucocyte infiltration, creatine kinase, myoglobin and subjective muscle soreness were unaffected by ibuprofen treatment when compared to placebo. There was also no association between increases in inflammatory leucocytes and any other marker of cellular muscle damage. CONCLUSION: Ibuprofen administration had no effect on the accumulation of neutrophils, markers of muscle damage or muscle soreness during the first 24 h of post-exercise muscle recovery