Objective: This study investigated the intervention effect of slow-velocity eccentric-only resistance training on type 2 diabetic mellitus (T2DM) patients based on the role of matrix metalloproteinase-2 and -9 (MMP-2 and -9) in regulating extracellular matrix homeostasis. Methods: 50 T2DM patients were randomly divided into the slow-velocity eccentric-only resistance training group (E) and control group (C). The E group performed eccentric-only resistance training 3 times a week, every other day for 10 weeks, while the C group did not. Blood samples were collected before and after training, and subjects were tested for changes in clinical parameters, insulin resistance indices [fasting insulin, homeostatic model assessment insulin resistance (HOMA-IR)], MMP-2 and -9, and hydroxyproline, and muscle strength (12-RM), respectively. Results: After 10 weeks of training, the E group showed significant decreases in fasting glucose (P < .05), insulin (P < .05), insulin resistance indices (P < .05), hemoglobin A1c (HbA1c) (P < .01), triglycerides (P = .06) and MMP-2 (P < .05), while total cholesterol (P < .05), MMP-9 (P < .05), hydroxyproline (P < .01), Creatine Kinase (CK) (P < .05), and muscle strength (P < .001) significantly increased. There were no significant changes in the count of neutrophil, lymphocyte and platelet, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c). Compared with the C group, the E group showed a trend of a significant decrease in triglyceride (P < .05), lymphocyte count (P < .05), fasting glucose (P = .07), and plasma MMP-2 (P < .05), while MMP-9 (P < .05), hydroxyproline (P < .001), and muscle strength (P < .01) significantly increased. However, no significant changes were observed in insulin and insulin resistance indices, HbA1c, total cholesterol, HDL-c, LDL-c, CK, and other inflammatory indicators. Conclusions: Slow-velocity eccentric-only resistance training was beneficial for T2DM, but the potential role of MMP-2 and -9 in regulating extracellular matrix homeostasis is very different in T2DM patients.

Background Carbohydrate (CHO) mouthwash improves performance by stimulating oral receptors linked to brain regions involved in motor control and motivation, without requiring digestive processing. Most research has focused on fasting states, but the effects of postprandial CHO mouthwash remain inconclusive. Objectives This study aims to synthesize existing studies on the impact of postprandial CHO mouthwash on exercise and cognitive performance, offering insights for future research and practical recommendations for athletes and coaches. Methods Six databases (Pubmed, Web of Science, Cochrane Library, Embase, SciELO and SPORTDiscus) were systematically searched for articles up to February 2025 and screened using EndNote 21th. Statistical analysis was conducted using metafor package in Rstudio (2024.09.1), and results were visualized with ggplot2 package. Results Thirty-five articles met inclusion criteria, with two studies on cognitive performance included in the systematic review and thirty-three on exercise performance included in both the systematic review and meta-analysis. Overall, CHO mouthwash was found to improve cognitive performance under fed conditions compared to placebo and meta-analysis further supported the enhancement of exercise performance (Hedges' g = 0.18, 95% CI [0.09, 0.28], p < 0.01). Moderator and meta-regression analysis revealed that CHO mouthwash appeared to be more effective in improving exercise performance under fed conditions when aerobic exercise was performed, maltodextrin mouthwash was used, mouthwash duration was ≤ 10 s, and a high-CHO meal was consumed before exercise (p < 0.05). Conclusion This systematic and meta-analytic review supports the view that CHO mouthwash can still improve exercise and cognitive performance under fed conditions.

Background: Citrulline malate (CM) is commonly used as an ergogenic supplement, but its effects on exercise performance and perceived exertion remain uncertain. This systematic review and meta-analysis evaluated the effects of CM supplementation, with attention paid to differences between acute and chronic protocols. Methods: Six databases were searched from inception to August 2025. Randomized controlled trials examining CM supplementation on exercise performance and/or perceived exertion were included. Hedges’ g was synthesized using three-level random-effects models to account for dependent effect sizes. Subgroup and moderator analyses explored supplementation protocol, exercise modality, sex, training status, dosage, and ingestion timing. Risk of bias, small-study effects, sensitivity analyses, and GRADE certainty were assessed. Results: Thirty randomized controlled trials contributed 138 effect sizes from 644 participants. CM supplementation was associated with a small improvement in overall exercise performance (g = 0.16, p = 0.01); however, prediction intervals were wide and statistical power was limited. The pooled effect on perceived exertion was not statistically significant. Current evidence appeared more stable for acute than chronic supplementation, although the protocol subgroup difference remained uncertain. Among acute studies, exploratory subgroup analyses suggested possible benefits for aerobic endurance and short anaerobic tasks, but these findings were not robust across sensitivity analyses. No significant between-subgroup differences were found for sex, training status, dosage, or ingestion timing. GRADE certainty ranged from low to very low. Conclusions: CM supplementation may be associated with small, context-dependent improvements in exercise performance, but current evidence remains limited and uncertain. Reliable dosing, timing, and target populations have not been established. Larger trials with verified supplement composition and standardized protocols are needed.

Objective: This randomized controlled trial evaluated the effects of unstable resistance training (URT) and stable resistance training (SRT) on muscle stiffness, co-activation, balance, and pain in older adults. To date, no study has investigated dose-matched instability-based resistance training in this population with prespecified endpoints of co-activation and muscle stiffness. Methods: Forty-six older adults were randomly assigned to either the URT ( n = 23) or SRT ( n = 23) group for a 12-week intervention. Both groups performed seven lower-limb exercises with matched volume and intensity, with the URT group utilizing instability devices. Outcomes included muscle–tendon stiffness in the quadriceps and hamstrings, co-activation during squat-down (SD), stand-up (SU), and transition (SUSD). Balance was assessed using the Y-Balance Test (YBT) and Balance Error Scoring System (BESS), and pain was measured with the visual analogue scale (VAS). Results: Compared with SRT, URT resulted in greater reductions in co-activation during SD ( p = 0.035), SU ( p = 0.003), and SUSD ( p = 0.001). URT also produced larger improvements in balance, as indicated by BESS ( p = 0.009), YBT-right ( p = 0.008), and YBT-left ( p < 0.001). Increases in muscle stiffness with URT were limited to the vastus medialis, quadriceps tendon, and hamstring tendon (all p < 0.05), whereas SRT produced broader increases in muscle–tendon stiffness (all p < 0.05). VAS scores decreased in both groups, with a greater reduction after URT ( p = 0.009). Conclusion: In older adults, URT more effectively reduced co-activation and enhanced balance under matched loads, while SRT increased muscle stiffness across a broader range of muscles. Given that both interventions reduced pain, the choice of intervention should depend on whether the primary objective is to improve coordination and balance or to increase muscle stiffness. Trial registration: UMIN Clinical Trials Registry, retrospectively registered. Registration number XXXX.