Eccentric-only versus concentric-only resistance training effects on biochemical and physiological parameters in patients with type 2 diabetes

Background: The benefits of resistance training for patients with type 2 diabetes (T2D) are well documented; however, the effects of exercise with different muscle contraction types such as eccentric versus concentric contractions on physiological outcomes for this population are not clear. This study compared eccentric-only (ECC) and concentric-only resistance training (CON) to test the hypothesis that ECC would be superior to CON to improve insulin sensitivity, lipid profile, body composition, muscle strength and physical function of patients with T2D. Methods: Adults with T2D (50–79 years) were allocated to the ECC (n = 9) or CON group (n = 9). Resistance exercises (chest press, lateral pulldown, bicep curl, triceps extension, leg extension, leg curl, calf raise, abdominal crunch) consisting of 2–3 sets of 10 eccentric-only (5 s) or concentric-only contractions (1–2 s) was performed twice a week for 12 weeks. Changes in blood biomarkers, body composition, muscle strength and physical function from pre- to post-intervention were compared between groups. Results: Overall rating of perceived exertion (RPE, 1–10 Borg scale) was lower (p \u3c 0.05) for ECC (2.9 ± 1.2) than CON (5.4 ± 1.1). No significant changes in blood biomarkers were found for both groups. Lean mass increased [effect size (ES) = 0.148, ECC 3.2 ± 6.9%; CON 3.6 ± 2.3%], and fat mass decreased (ES = 0.545, ECC − 6.1 ± 12.4%; CON − 7.1 ± 16.4%) (p \u3c 0.05) similarly. One-repetition maximal strength of each exercise increased (p \u3c 0.05) for both ECC (12–37%) and CON (27–68%). Both groups improved (p \u3c 0.05) 6-min walk distance (ES = 0.083, ECC 12.2 ± 2.3%; CON 12.5 ± 15.3%) and chair rise time (ES = 0.463, ECC − 13.4 ± 25.4%; CON − 20.0 ± 53.3%) but only ECC improved (p \u3c 0.05) the timed up-and-go test (− 11.3 ± 13.6%, ES 0.014). No significant changes in balance tests were found for both groups. Conclusion: These results did not fully support the hypothesis but showed that ECC was as effective as CON to improve body composition, muscle strength, and physical function with lesser RPE. Future studies should investigate whether larger differences between ECC and CON are evident when increasing the exercise frequency and matching the intensities of the two-exercise protocols. Trial registration ACTRN12621001026819 (retrospectively registered on 5th Aug 2021)

What are the most effective exercise, physical activity and dietary interventions to improve body composition in women diagnosed with or at high-risk of breast cancer? A systematic review and network meta-analysis

Background: Obesity has been recognized as a risk factor in the development and recurrence of breast cancer and is also associated with poor prognostic outcomes. This systematic review and network meta-analysis aimed to identify the most effective exercise, physical activity, and dietary interventions to reduce fat mass, body fat percentage and body weight as well as potentially increase lean mass in women diagnosed with or at high risk of breast cancer. Methods: A systematic search of databases was performed up to May 2022. Eligible randomized controlled trials examined the effects of exercise, physical activity and/or dietary interventions on fat mass and lean mass in women diagnosed with or at high risk of breast cancer. A random-effects network meta-analysis was conducted to determine the effects of different interventions across outcomes when sufficient studies were available. Results: Eighty-four studies (n = 6428) were included in this review. Caloric restriction and combined exercise + caloric restriction significantly reduced fat mass (range, –3.9 to –3.7 kg) and body weight (range, –5.3 to –4.7 kg), whereas physical activity + caloric restriction significantly reduced body fat percentage (–2.4%; 95% confidence interval [CI], –3.4% to –13%) and body mass index (–2.2 kg × m–2; 95% CI, –3.0 to –1.4 kg × m–2) in breast cancer patients. Resistance exercise was the most effective intervention to increase lean mass (0.7 kg; 95% CI, 0.5–1.0 kg) in breast cancer patients. Conclusion: Multimodal exercise and diet programs were the most effective interventions to reduce fat mass, body fat percentage, and body weight and increase and/or preserve lean mass

Weight loss for overweight and obese patients with prostate cancer: A study protocol of a randomised trial comparing clinic-based versus telehealth delivered exercise and nutrition intervention (the TelEX trial)

Introduction Obese men with prostate cancer have an increased risk of biochemical recurrence, metastatic disease and mortality. For those undergoing androgen deprivation therapy (ADT), substantial increases in fat mass are observed in the first year of treatment. Recently, we showed that a targeted supervised clinic-based exercise and nutrition intervention can result in a substantial reduction in fat mass with muscle mass preserved in ADT-treated patients. However, the intervention needs to be accessible to all patients and not just those who can access a supervised clinic-based programme. The purpose of this study was to evaluate the efficacy of telehealth delivered compared with supervised clinic-based delivered exercise and nutrition intervention in overweight/obese patients with prostate cancer. Methods and analysis A single-blinded, two-arm parallel group, non-inferiority randomised trial will be undertaken with 104 overweight/obese men with prostate cancer (body fat percentage ≥ 25%) randomly allocated in a ratio of 1:1 to a telehealth-delivered, virtually supervised exercise and nutrition programme or a clinic-based, face-to-face supervised exercise and nutrition programme. Exercise will consist of supervised resistance and aerobic exercise performed three times a week plus additional self-directed aerobic exercise performed 4 days/week for the first 6 months. Thereafter, for months 7-12, the programmes will be self-managed. The primary endpoint will be fat mass. Secondary endpoints include lean mass and abdominal aortic calcification, anthropometric measures and blood pressure assessment, objective measures of physical function and physical activity levels, patient-reported outcomes and blood markers. Measurements will be undertaken at baseline, 6 months (post intervention), and at 12 months of follow-up. Data will be analysed using intention-to-treat and per protocol approaches. Ethics and dissemination Ethics approval has been obtained from the Edith Cowan University Human Research Ethics Committee (ID: 2021-02157-GALVAO). Outcomes from the study will be published in academic journals and presented in scientific and consumer meetings. Trial registration number: ACTRN12621001312831

Effects of eccentric versus concentric resistance training in adults with Type 2 Diabetes

The benefits of resistance training for people with Type 2 diabetes (T2D) are well documented; however, the effects of different muscle contraction types (e.g. eccentric, concentric) on physiological outcomes for this population are still unclear. This study investigated the effects of eccentric (ECC) versus concentric (CON) resistance training on blood markers, muscle strength, physical functional performance and body composition. Eighteen adults with T2D (Age: 64.8 ± 9.0 y; BMI: 30.3 ± 4.1 kg/m2) were randomly assigned to either an ECC (n = 9) or a CON (n = 9) group. Participants performed 2 or 3 sets of 10 eccentric (5-s) or concentric (2-s) contractions of eight upper and lower body resistance exercises, twice a week for 12 weeks. Training intensity gradually increased from 10 to 100% of 1-repetition maximum concentric strength (1-RM) for the ECC group and from 50 to 100% of 1-RM strength for the CON group, based on the 1-RM at baseline. Blood markers (glucose, insulin, HbA1c, HOMA2-IR, cholesterol, triglycerides, HDL and LDL), muscle strength (1- RM), body composition (dual-energy x-ray absorptiometry), and physical functional performance tests consisting of 6-min walk (6MWT), chair rise (CR), timed up-and-go (TUG), and balance were measured before and after the intervention, and the changes were compared between groups. Significant differences in the improvement between the ECC and CON group were found for 1-RM strength for bicep curl (ECC: 11%, CON: 27%), calf raise (ECC: 37%, CON: 68%) and abdominal crunch (ECC: 22%, CON: 42%) exercises, hip circumference (ECC: -1%, CON: -5%) and SF-36 pain measures (ECC: 6%, CON: -1%). Muscle strength significantly increased more for the CON group (27–68%) than the ECC group (12–37%) which was likely due to greater combined total load lifted in the CON (143,262 ± 57,972 kg) than the ECC group (111,678 ± 51,225 kg). Significant improvements (p \u3c 0.05) were also found in the ECC group for the 6MWT (56.8 ± 2.2 m), TUG (-0.8 ± 0.3 s) and CR (-1.8 ± 1.4 s), while the CON group significantly improved the 6MWT (63.4 ± 12.0 m) and CR (-2.3 ± 1.6 s). Total equilibrium balance increased by 7.0% in the ECC group and 4.3% in the CON group. Body composition improved similarly for both groups including significant reductions in total fat mass (ECC: -2.0 ± 1.3 kg, CON: -2.2 ± 1.2 kg) and significant increase in total lean mass (ECC: 1.8 ± 0.7 kg, CON: 2.0 ± 0.2 kg). No significant changes were found in blood markers for both groups. These results showed that ECC training performed at lower intensities (RPE: 4.1 ± 2.1) was as effective as CON training for improving physical functional performance, strength and body composition. These findings suggest that focusing on eccentric contractions in resistance training is beneficial and well-tolerated in adults with T2D