Effects of Cycling Intensity on Acute Signaling Adaptations to 8-weeks Concurrent Training in Trained Cyclists

The Impact of 8 Weeks of Combined Physical Exercise Training on SIRT3 and mTOR in Lymphocytes, and on Lipid Peroxidation

The sirtuins (SIRT) protein family and the mechanistic/mammalian target of rapamycin (mTOR) are intracellular molecules that have been involved in the regulation of several biological processes, as well as in various aging-related processes. This pilot study, in small scale, aimed to analyze the effects of an 8-week physical exercise program on SIRT3 and mTOR levels in lymphocytes, as well as on lipid peroxidation in middle aged and older men. A total of 9 participants aged between 56 and 73 years were enrolled in an 8-week physical exercise program comprising cardiovascular and high-intensity interval training. The program involved three sessions per week, each lasting 45-60 min, conducted on non-consecutive days. Tests were conducted before and after the experimental period (pre- and post-training). Assessments included a vertical jump, 20 m velocity, ball throwing, and an aerobic capacity test. Lipid peroxidation (MDA) was measured in plasma as an oxidative stress biomarker. Additionally, sirtuin 3 (SIRT3/β-actin) and mTOR (mTOR/β-actin) levels were measured in isolated lymphocytes extracted from venous blood. Following the exercise training period, our results demonstrated a significant improvement in aerobic capacity (pre-training: 615.4 ± 45.3 m; post-training: 687.2 ± 34.6 m; t = -2.521; p = 0.012) and 20 m velocity (pre-training: 4.6 ± 0.5 s; post-training: 4.3 ± 0.3 s; t = -2.023; p = 0.04). Concerning blood variables, there was a significant decrease in mTOR levels (pre-training: 0.857 ± 0.593; post-training: 0.214 ± 0.097; t = -2.547; p = 0.011), while no changes were observed in SIRT3 (pre-training: 0.608 ± 0.404; post-training: 0.516 ± 0.390; t = 0.533; p = 0.594) and MDA (pre-training: 8420 ± 4615; post-training: 8800 ± 3163; t = -0.533; p = 0.594). The notable reduction in mTOR levels in lymphocytes following the 8-week physical exercise program suggests a potential role of exercise in modulating immune cell dynamics, particularly in middle-aged and older individuals. Furthermore, the exercise regimen resulted in improvements in physical function, including enhanced aerobic capacity and walking velocity.

Comparative efficacy of concurrent training types on lower limb strength and muscular hypertrophy: A systematic review and network meta-analysis

Objective

This study aims to compare, through quantitative analysis, the effectiveness of different endurance training types on increasing lower limb strength and muscle cross-sectional area (MCSA) in concurrent training.

Methods

This systematic literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) [PROSPERO ID: CRD42023396886]. Web of Science, SportDiscuss, Pubmed, Cochrane, and Scopus were systematically searched from their inception date to October 20, 2023.

Results

A total of 40 studies (841 participants) were included in this meta-analysis. MCSA analysis showed that, compared to resistance training alone, concurrent high-intensity interval running training and resistance training and concurrent moderate-intensity continuous cycling training and resistance training were more effective (SMD = 0.15, 95% CI = -0.46 to 0.76, and SMD = 0.07, 95% CI = -0.24 to 0.38 respectively), while other modalities of concurrent training not. Lower body maximal strength analysis showed that all modalities of concurrent training were inferior to resistance training alone, but concurrent high-intensity interval training and resistance training showed an advantage in four different concurrent training modalities (SMD = -0.08, 95% CI = -0.25 to 0.08). For explosive strength, only concurrent high-intensity interval training and resistance training was superior to resistance training (SMD = 0.06, 95% CI = -0.21 to 0.33).

Conclusion

Different endurance training types have an impact on the effectiveness of concurrent training, particularly on lower limb strength. Adopting high-intensity interval running as the endurance training type in concurrent training can effectively minimize the adverse effects on lower limb strength and MCSA.

Effect of Core Muscle Strength Training Combined with Taijiquan on Bone Mineral Density Measured by Quantitative CT Scanning in the Elderly

Learn about the benefits of muscle strength training combined with tai chi for adult skeletal muscle in multiple CT scanning. The study included 182 people over the age of 60 with no long-term history of physical activity and exercise. They were divided into the Taijiquan group (52 people), student muscle strength group (45 people), student muscle group combined with Taijiquan group (45 people), and control group (40 people). The board of directors did not attend. The other three groups received tai chi (more than 4 times a week), muscle strength training, and muscle training combined with tai chi for 6 months. Lumbar spine (L1-4) BMD and Berg scores were approximately the same as those measured in adults before exercise and at 3 and 6 months after exercise. The results showed that there were significant differences in the scores of lumbar spine BMD and Berg Balance Scale between the Taijiquan group and students before and after exercise combined with muscle strength training (P < 0.05 or <0.01). The difference was statistically significant (P < 0.05). The scores of lumbar BMD and Berg Balance Scale in the core muscle strength training combined with Taijiquan group after 6 months of exercise were higher than those after 3 months of exercise (P < 0.05), and the CT value of lumbar vertebral bone calcium was significantly positively correlated with BMD (Pearson correlation coefficients of L5 vertebral body were r = 0.704, 0.683, 0.728, 0.673, and 0.686, P < 0.01). Single or combined training of core muscle strength or Taijiquan can improve lumbar bone mineral density and balance function in the elderly.