Background: This study investigated the effects of combined Rhodiola rosea (RHO) and caffeine (CAF) supplementation on lower limb explosive power and fatigue recovery in volleyball players, aiming to validate their potential synergistic effects. Methods: A randomized, double-blind, placebo-controlled design was implemented involving 48 male volleyball athletes allocated into four groups: placebo (CTR), Rhodiola rosea (RHO), caffeine (CAF), and combined (RHO + CAF). Over four weeks, participants engaged in twice-weekly high-intensity lower limb resistance training, with performance evaluated through multiple tests, including two-step-approach jump height, countermovement jump (CMJ), five-jump test (5 JT), continuous 20 vertical jumps, and intermittent jump recovery alongside Rate of Perceived Exertion (RPE) assessments. Results: Results showed that the combined supplementation (RHO + CAF) group exhibited significant improvement across multiple performance metrics. In particular, the combined group demonstrated the highest increases in jump height and the least power decline during high-frequency jumps, outperforming the CTR and other supplementation groups (p < 0.05). Additionally, RHO + CAF supplementation significantly lowered RPE scores, particularly in the final week of training, indicating improved perceived fatigue and recovery. Conclusions: This study suggests that combining RHO and CAF optimizes high-intensity performance by enhancing explosive power, reducing fatigue, and improving recovery, presenting an effective nutritional strategy for volleyball athletes.

Background: Post-exercise recovery involves coordinated metabolic restoration and redox rebalancing. Although dietary polyphenols have been proposed to facilitate recovery, the metabolic mechanisms underlying their effects—particularly during the recovery phase—remain insufficiently characterized. This study aimed to investigate how polyphenol supplementation modulates post-exercise metabolic recovery using an integrative metabolomics approach. Methods: We conducted a secondary analysis of publicly available longitudinal human LC–MS metabolomics datasets from exercise intervention studies with polyphenol supplementation. Datasets were obtained from the NIH Metabolomics Workbench and MetaboLights repositories; study-level metadata were used as provided by the original investigators. Global metabolic trajectories were assessed using principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Targeted analyses focused on purine degradation intermediates and redox-related metabolites. Correlation-based network and pathway enrichment analyses were applied to characterize recovery-phase metabolic reorganization. Results: Exercise induced a pronounced global metabolic perturbation in both placebo and polyphenol groups. During recovery, polyphenol supplementation was associated with a partial reversion of the metabolome toward the pre-exercise state, whereas placebo samples remained metabolically displaced. Discriminant metabolite analyses identified purine degradation intermediates and oxidative stress-related lipid species as key contributors to group separation during recovery. Polyphenol supplementation attenuated recovery-phase accumulation of hypoxanthine, xanthine, and uric acid and was associated with a sustained suppression of the uric acid-to-hypoxanthine ratio. Network analyses revealed weakened correlations between purine metabolites and oxidative stress markers, along with reduced network centrality of stress-responsive metabolic hubs. Conclusions: These findings indicate that polyphenol supplementation is associated with accelerated metabolic normalization during post-exercise recovery, potentially through modulation of purine-associated oxidative pathways and system-level metabolic network reorganization.

Background: Explosive lower limb power, a critical determinant of success in volleyball, is a prime candidate for focused research. Consequently, nutritional supplements are commonly employed to gain an ergogenic edge. Despite this widespread practice, a comprehensive and evidence-based ranking of supplements for improving this key attribute is lacking, leaving athletes and practitioners without targeted evidence to guide decisions. Methods: PubMed, Web of Science, CENTRAL, and Embase were searched from inception to 1 August 2025. We included RCTs in volleyball athletes (≥14 years) with ≥1-week interventions and relevant explosive lower limb performance outcomes. A Bayesian NMA estimated effects with 95% credible intervals (CrIs) and SUCRA; certainty was appraised with CINeMA. Results: A total of 35 RCTs (n = 838 volleyball athletes) examining 13 different supplements were included. The results indicated that β-alanine was associated with the greatest improvement in vertical jump (MD 4.6; 95% CrI 1.2–7.8), followed by creatine (MD 3.7; 0.57–6.9) and caffeine (MD 2.1; 0.06–4.1). It also appeared to be the most promising method for substantially increasing lower limb peak power (SMD 1.1; 0.21–2.0). No statistically significant improvement was found in lower limb mean power, and no serious adverse events were reported. Conclusions: Among volleyball athletes, β-alanine appeared most promising effective supplement for enhancing key components of explosive lower limb performance, specifically vertical jump height and peak power. Creatine and caffeine are also effective for improving vertical jump height. However, these findings are based on low-to-moderate certainty of evidence; they should be interpreted with caution and regarded as preliminary. Supplement strategies should be individualized by age and competitive level; further, high-quality, standardized randomized controlled trials are warranted to validate these initial observations.

Introduction: This study examined the effects of probiotic supplementation alone or combined with aerobic exercise on antioxidant capacity and oxidative stress after high-intensity interval exercise (HIIE) in college students.Methods: Thirty male college students were divided into three groups: control (C), probiotic (P), and combined probiotic and exercise (PE). The 6-week intervention involved moderate-intensity cycling three times a week. All participants underwent a single session of HIIE protocol. The tests for maximal oxygen uptake (VO₂max), elimination rate of lactic acid (ER), blood oxidative stress markers, and blood rheology were performed.Results: A decrease in superoxide dismutase (SOD) activity was observed at baseline in the P and PE groups (P < 0.01), while significantly increased glutathione peroxidase (GSH-Px) activity and reduced catalase activity were found in the PE group (P < 0.05). In the P and PE groups, SOD activity (P < 0.01) and total antioxidant capacity (T-AOC) level (P < 0.01) were significantly elevated after HIIE. The T-AOC level significantly increased from 0.47 ± 0.03 umol Trolox/mL to 0.78 ± 0.07 umol Trolox/mL in the P group and from 0.56 ± 0.04 umol Trolox/mL to 0.82 ± 0.05 umol Trolox/mL in the PE group. The 8-OHdG level increased significantly in both the C and P groups (P < 0.05), but remained unchanged in the PE group after the intervention. High shear rate whole blood viscosity was significantly decreased in the P and PE groups (P < 0.05). Additionally, a notable decline in plasma viscosity was observed in the PE group. After the intervention, medium and high shear rate whole blood viscosity levels (P < 0.05) were significantly lower in the PE group than in the C group, and plasma viscosity was dropped by 28.64% (P < 0.05). Following the intervention, a significant elevation in VO₂max was only observed in the PE group from 38.14 ± 3.11 to 44.5 ± 2.94 mL/kg/min (P < 0.05), with a subsequent increase in ER detected after HIIE (P < 0.05).Discussion: These findings indicate that combining probiotics with aerobic exercise enhances antioxidant and aerobic capacity more effectively than probiotics alone.

Objective: Seaweed and microalgae provide antioxidants, polyunsaturated fatty acids, and bioactive compounds that may enhance exercise performance and accelerate recovery. However, evidence remains inconsistent. This systematic review and meta-analysis aimed to evaluate the effects of algae-derived supplementation on exercise performance and physiological recovery outcomes in healthy and athletic adults. Methods: This review was registered in PROSPERO (CRD420251166723) and conducted in accordance with PRISMA 2020 guidelines. PubMed, Web of Science, Embase, Cochrane Library, EBSCO, and CNKI were systematically searched for randomized controlled trials (RCTs) evaluating algae supplementation in exercise contexts. Inclusion and exclusion criteria were defined based on the PICOS framework. Primary outcomes included VO₂max, Time to exhaustion (TTE), maximal power output (WRmax), Time-Trial (TT) performance, and creatine kinase (CK). Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Subgroup, sensitivity, and publication bias analyses were performed. Results: Twenty-two RCTs (n = 822) investigating Spirulina, Chlorella, brown-algal polysaccharides, or astaxanthin met inclusion criteria. Algae supplementation showed a suggestive improvement in VO₂max (SMD = 0.88, 95% CI: 0.00–1.75) and significantly improved in TTE (SMD = 1.06, 95% CI: 0.16–1.96), with smaller effects on WRmax (SMD = 0.29, 95% CI: 0.03–0.55), and no significant benefit for TT performance (SMD = −0.27, 95% CI: −0.74 to 0.21). Regarding recovery, CK concentrations were significantly reduced (SMD = −0.78, 95% CI: −1.28 to −0.28). Subgroup analysis suggested greater effects for Chlorella supplementation, higher dosages, and aerobic training contexts; reductions in muscle-damage markers were more evident following resistance exercise. Sensitivity analyses supported the robustness of the main findings with minimal evidence of publication bias. Conclusions: Algae-derived supplements—particularly Spirulina and Chlorella—may modestly enhance aerobic exercise performance and attenuate exercise-induced muscle damage under certain conditions. Effects appear to depend on algae species, dosing strategies, intervention duration, and training modality. High-quality, multi-center RCTs incorporating mechanistic endpoints are needed to clarify optimal application and to develop athlete-specific recommendations.