Elastic tubes: The ideal equipment for telehealth exercise medicine in the management of prostate cancer?

Prostate cancer (PCa) affects 1 in 8 men, but exercise therapy has been shown to be a very effective intervention not only to induce physiological benefits but to also reduce the side effects of cancer treatments typically administered during PCa. The COVID19 pandemic has restricted access to exercise clinics, a problem which always existed for people living in rural and remote areas. This caused many exercise physiologists and researchers to transition their clinic-based exercise to online, home-based exercise. We would like to propose that researchers and exercise physiologists should consider the use of elastic tubes in both research and the clinical management of PCa, when exercise programs are administered remotely, as their characteristics make them an ideal exercise equipment. In this article, the characteristics, considerations, and information on quantifying exercise dosage when using elastic tubes in remote exercise delivery are discussed

Exercise builds the scaffold of life: muscle extracellular matrix biomarker responses to physical activity, inactivity, and aging

Skeletal muscle extracellular matrix (ECM) is critical for muscle force production and the regulation of important physiological processes during growth, regeneration, and remodelling. ECM remodelling is a tightly orchestrated process, sensitive to multi-directional tensile and compressive stresses and damaging stimuli, and its assessment can convey important information on rehabilitation effectiveness, injury, and disease. Despite its profound importance, ECM biomarkers are underused in studies examining the effects of exercise, disuse, or aging on muscle function, growth, and structure. This review examines patterns of short- and long-term changes in the synthesis and concentrations of ECM markers in biofluids and tissues, which may be useful for describing the time course of ECM remodelling following physical activity and disuse. Forces imposed on the ECM during physical activity critically affect cell signalling while disuse causes non-optimal adaptations, including connective tissue proliferation. The goal of this review is to inform researchers, and rehabilitation, medical, and exercise practitioners better about the role of ECM biomarkers in research and clinical environments to accelerate the development of targeted physical activity treatments, improve ECM status assessment, and enhance function in aging, injury, and disease

Pathological mechanisms and therapeutic outlooks for arthrofibrosis

Arthrofibrosis is a fibrotic joint disorder that begins with an inflammatory reaction to insults such as injury, surgery and infection. Excessive extracellular matrix and adhesions contract pouches, bursae and tendons, cause pain and prevent a normal range of joint motion, with devastating consequences for patient quality of life. Arthrofibrosis affects people of all ages, with published rates varying. The risk factors and best management strategies are largely unknown due to a poor understanding of the pathology and lack of diagnostic biomarkers. However, current research into the pathogenesis of fibrosis in organs now informs the understanding of arthrofibrosis. The process begins when stress signals stimulate immune cells. The resulting cascade of cytokines and mediators drives fibroblasts to differentiate into myofibroblasts, which secrete fibrillar collagens and transforming growth factor-β (TGF-β). Positive feedback networks then dysregulate processes that normally terminate healing processes. We propose two subtypes of arthrofibrosis occur: active arthrofibrosis and residual arthrofibrosis. In the latter the fibrogenic processes have resolved but the joint remains stiff. The best therapeutic approach for each subtype may differ significantly. Treatment typically involves surgery, however, a pharmacological approach to correct dysregulated cell signalling could be more effective. Recent research shows that myofibroblasts are capable of reversing differentiation, and understanding the mechanisms of pathogenesis and resolution will be essential for the development of cell-based treatments. Therapies with significant promise are currently available, with more in development, including those that inhibit TGF-β signalling and epigenetic modifications. This review focuses on pathogenesis of sterile arthrofibrosis and therapeutic treatments. © 2019, The Author(s)

ジテンシャヲモチイタカタアシシンチョウセイシュウシュクウンドウ1ニチゴニショウジルヒザシンテンキンツウハウンドウチョクゴノトウシャクセイキンシュウシュクキンリョクテイカノテイドカラヨソクデキル

　伸張性収縮運動は優れた筋力トレーニング方法の一つであるが，遅発性筋痛（DOMS）が生じやすく，その後の運動パフォーマンスに影響を与える。しかし，どのくらいDOMSが生じるかは予測できない。そこで，自転車エルゴメーター（自転車）を用いた伸張性収縮サイクリング（運動）を実施し，その直後の筋力低下の程度からDOMSの程度が予測できないか調べた。対象は健常成人13名とし，50回/分で逆回転する自転車で右足のみの50回運動を1セットとし，1分間の休憩をはさみながら10セット行った。その前後に膝伸展・屈曲筋力を測定した。また運動前と1日後に外側広筋を圧迫した際の痛みの程度と圧痛閾値も測定した。そして運動後の筋力低下率と痛みの変化量あるいは圧痛閾値低下率の相関を調べた。その結果，等尺性膝伸展筋力の低下率と痛みの変化量や圧痛閾値低下率は有意な相関を認め，運動直後の筋力低下の程度から翌日に生じる筋痛の程度が予測可能なことを示した

Comparison between high- and low-intensity eccentric cycling of equal mechanical work for muscle damage and the repeated bout effect

Purpose: We compared high- and low-intensity eccentric cycling (ECC) with the same mechanical work for changes in muscle function and muscle soreness, and examined the changes after subsequent high-intensity ECC. Methods: Twenty men performed either high-intensity ECC (1 min × 5 at 20% of peak power output: PPO) for two bouts separated by 2 weeks (H–H, n = 11), or low-intensity (4 min × 5 at 5% PPO) for the first and high-intensity ECC for the second bout (L–H, n = 9). Changes in indirect muscle damage markers were compared between groups and bouts. Results: At 24 h after the first bout, both groups showed similar decreases in maximal isometric (70° knee angle, − 10.6 ± 11.8%) and isokinetic (− 11.0 ± 8.2%) contraction torque of the knee extensors (KE), squat (− 7.7 ± 10.4%) and counter-movement jump (− 5.9 ± 8.4%) heights (p \u3c 0.05). Changes in KE torque and jump height were smaller after the second than the first bout for both the groups (p \u3c 0.05). Increases in plasma creatine kinase activity were small, and no significant changes in vastus lateralis or intermedius thickness nor ultrasound echo-intensity were observed. KE soreness with palpation was greater (p \u3c 0.01) in H–H (peak: 4.2 ± 1.0) than L–H (1.4 ± 0.6) after the first bout, but greater in L–H (3.6 ± 0.9) than H–H (1.5 ± 0.5) after the second bout. This was also found for muscle soreness with squat, KE stretch and gluteal palpation. Conclusion: The high- and low-intensity ECC with matched mechanical work induced similar decreases in muscle function, but DOMS was greater after high-intensity ECC, which may be due to greater extracellular matrix damage and inflammation. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature

Exercise medicine for cancer cachexia: Targeted exercise to counteract mechanisms and treatment side-effects

Purpose: Cancer-induced muscle wasting (i.e., cancer cachexia, CC) is a common and devastating syndrome that results in the death of more than 1 in 5 patients. Although primarily a result of elevated inflammation, there are multiple mechanisms that complement and amplify one another. Research on the use of exercise to manage CC is still limited, while exercise for CC management has been recently discouraged. Moreover, there is a lack of understanding that exercise is not a single medicine, but mode, type, dosage, and timing (exercise prescription) have distinct health outcomes. The purpose of this review was to examine the effects of these modes and subtypes to identify the most optimal form and dosage of exercise therapy specific to each underlying mechanism of CC. Methods: The relevant literatures from MEDLINE and Scopus databases were examined. Results: Exercise can counteract the most prominent mechanisms and signs of CC including muscle wasting, increased protein turnover, systemic inflammation, reduced appetite and anorexia, increased energy expenditure and fat wasting, insulin resistance, metabolic dysregulation, gut dysbiosis, hypogonadism, impaired oxidative capacity, mitochondrial dysfunction, and cancer treatments side-effects. There are different modes of exercise, and each mode has different sub-types that induce vastly diverse changes when performed over multiple sessions. Choosing suboptimal exercise modes, types, or dosages can be counterproductive and could further contribute to the mechanisms of CC without impacting muscle growth. Conclusion: Available evidence shows that patients with CC can safely undertake higher-intensity resistance exercise programs, and benefit from increases in body mass and muscle mass

The effects of home-based exercise therapy for breast cancer-related fatigue induced by radical radiotherapy

Background: Radiotherapy (RT) can lead to cancer-related fatigue (CRF) and decreased health-related quality of life (HRQoL) in breast cancer patients. The purpose of this trial was to examine the feasibility and efficacy of a home-based resistance and aerobic exercise intervention for reducing CRF and improving HRQoL in breast cancer patients during RT. Methods: Women with breast cancer (N = 106) commencing RT were randomized to 12 weeks of home-based resistance and aerobic exercise (EX) or usual care/control (CON). The primary endpoint was CRF, with secondary endpoints of HRQoL, sleep duration and quality, and physical activity. Measurements were undertaken prior to RT, at completion of RT (~ 6 weeks), at completion of the intervention (12 weeks), and 6 and 12 months after RT completion, while CRF was also measured weekly during RT. Results: Eighty-nine women completed the study (EX = 43, CON = 46). Over the 12-week intervention, EX completed 1 – 2 resistance training sessions and accumulated 30–40 min of aerobic exercise weekly. For CRF, EX had a quicker recovery both during and post-RT compared to CON (p \u3c 0.05). Moreover, there was a significant difference in HRQoL between groups at RT completion, with HRQoL unchanged in CON and higher in EX (p \u3c 0.05). There was no change in sleep duration or quality for either group and there were no exercise-related adverse effects. Conclusions: Home-based resistance and aerobic exercise during RT is safe, feasible, and effective in accelerating CRF recovery and improving HRQoL. Improvements in CRF and HRQoL for these patients can be achieved with smaller exercise dosages than stated in the generic recommendations for breast cancer

Changes in plasma hydroxyproline and plasma cell-free DNA concentrations after higher- versus lower-intensity eccentric cycling

Purpose: We examined changes in plasma creatine kinase (CK) activity, hydroxyproline and cell-free DNA (cfDNA) concentrations in relation to changes in maximum voluntary isometric contraction (MVIC) torque and delayed-onset muscle soreness (DOMS) following a session of volume-matched higher- (HI) versus lower-intensity (LI) eccentric cycling exercise. Methods: Healthy young men performed either 5 × 1-min HI at 20% of peak power output (n = 11) or 5 × 4-min LI eccentric cycling at 5% of peak power output (n = 9). Changes in knee extensor MVIC torque, DOMS, plasma CK activity, and hydroxyproline and cfDNA concentrations before, immediately after, and 24–72 h post-exercise were compared between groups. Results: Plasma CK activity increased post-exercise (141 ± 73.5%) and MVIC torque decreased from immediately (13.3 ± 7.8%) to 48 h (6.7 ± 13.5%) post-exercise (P \u3c 0.05), without significant differences between groups. DOMS was greater after HI (peak: 4.5 ± 3.0 on a 10-point scale) than LI (1.2 ± 1.0). Hydroxyproline concentration increased 40–53% at 24–72 h after both LI and HI (P \u3c 0.05). cfDNA concentration increased immediately after HI only (2.3 ± 0.9-fold, P \u3c 0.001), with a significant difference between groups (P = 0.002). Lack of detectable methylated HOXD4 indicated that the cfDNA was not derived from skeletal muscle. No significant correlations were evident between the magnitude of change in the measures, but the cfDNA increase immediately post-exercise was correlated with the maximal change in heart rate during exercise (r = 0.513, P = 0.025). Conclusion: Changes in plasma hydroxyproline and cfDNA concentrations were not associated with muscle fiber damage, but the increased hydroxyproline in both groups suggests increased collagen turnover. cfDNA may be a useful metabolic-intensity exercise marker

Muscle damage and adaptations induced by eccentric cycling in relation to extracellular matrix

Both the acute damage and resulting adaptations induced by eccentric exercise have been well documented, but less is known about their underpinning mechanisms. It is possible that muscle extracellular matrix (ECM), including both collagenous and costameric (e.g. integrins) components, plays a major role in both damage and adaptation, but this has not been extensively investigated. Eccentric cycling (ECC) was chosen as a model to investigate these mechanisms, since it consists only of eccentric muscle actions, and can induce typical characteristics of muscle damage such as prolonged decreases in muscle function and delayed onset muscle soreness (DOMS); while ECC training has been shown to induce increases in muscle function and muscle mass, even at low intensities. The purpose of this PhD project was to investigate the muscle damage and adaptations induced by the ECC in relation to collagen breakdown and integrin signalling pathways, which may shed light on the connection between ECM-mediated muscle changes. This research project consisted of three studies. In Study 1, high- (HI) and low-intensity (LI) ECC with the same mechanical work were compared for changes in muscle function and DOMS, while the repeated bout effect was examined after subsequent HI ECC. Eleven men performed HI-ECC (1 min × 5 at 20% of peak power output: PPO) for two bouts separated by 2 weeks (H-H), and nine men performed LI-ECC (4 min × 5 at 5% PPO) for the first bout and then HI-ECC for the second bout (L-H). At 24 h after the first bout, both groups showed similar decreases in maximal isometric (70° knee angle, -10.6±11.8%) and isokinetic (-11.0±8.2%) knee extensor (KE) torque, and squat (-7.7±10.4%) and counter-movement (-5.9±8.4%) jump heights (P In Study 2, plasma CK activity, hydroxyproline (Hyp) and cell-free DNA (cfDNA) concentrations were measured before, immediately after and 24 – 72 h after HI-ECC and LI-ECC, and examined in relation to changes in maximum voluntary isometric contraction strength (MVIC) and DOMS. The participants were the same as those in Study 1. Plasma CK activity increased at 24 h (135%), and Hyp concentration increased (40–53%, P In Study 3, changes in the expression of integrin – integrin-linked kinase (ILK) – rapamycin-insensitive companion of mTOR (RICTOR) protein complex in VL before and after 8 weeks of HI-ECC training were examined along with possible associations to changes in muscle function and VL cross-sectional area (CSA) from pre- to post-training. Eleven young men completed 24 sessions of ECC with progressive increases in intensity and duration, resulting in a 2-fold increase in work from the first 3 sessions (75.4±14.1 kJ) to the last 3 sessions (150.7±28.4 kJ). Lower-limb lean mass (dual-energy X-ray absorptiometry), VL CSA (extended field-of-view ultrasonography), lower-limb static strength measured on the ergometer (breaking strength against the force provided by the crank pushing the foot), peak and average cycling power output were measured, and VL micro-biopsy samples were obtained before and after training. Significant (P The findings from the three studies provide new insights into the mechanisms underlying muscle damage and adaptations induced by eccentric exercise. The Study 1 results showed that even low-intensity eccentric muscle actions affected the ECM, as indicated by DOMS, which has been shown by previous studies to be more associated with connective tissue damage and inflammation. ECC did not induce extensive muscle fibre damage, as indicated by the small increases in plasma CK activity. It is interesting that the increases in plasma Hyp concentration were similar between HI-ECC and LI-ECC, despite a significant difference in DOMS magnitude. ECC training increased integrin-ILK-RICTOR expression, but it was not associated with the increased CSA or muscle function. It seems possible that the ECM is involved in muscle damage and adaptations, but this was not endorsed by the present studies. It is necessary to investigate further histological changes in ECM after the initial and repeated bouts of eccentric exercise, how eccentric exercise induces ECM remodelling, and how this affects changes in muscle architecture including muscle CSA or mass and muscle function