Effects of uphill running on muscle strength, jumping performance, running time, and aerobic capacity outcomes in athletes and recreational adults: A systematic review and meta-analysis.

内容摘要

Uphill running is widely used in athletic training to improve lower-limb strength, jumping performance, running ability, and aerobic capacity. However, randomized controlled trials (RCTs) have reported inconsistent findings, and no prior review has focused exclusively on uphill running across these domains. This systematic review and meta-analysis aimed to evaluate the effects of structured uphill running on muscle strength, jumping performance, running time, and aerobic capacity in athletes and recreationally active adults. Six databases (CINAHL, Embase, PubMed, Scopus, SPORTDiscus, Web of Science) were searched up to June 2025 for RCTs comparing uphill running with downhill, level ground, or usual training. Methodological quality was assessed using the Physiotherapy Evidence Database scale and Cochrane risk-of-bias tool. A random-effects meta-analysis was performed, with effect sizes expressed as standardized mean differences (SMDs) and 95% confidence intervals (CIs). Thirteen RCTs (2006-2023; n = 308; mean Physiotherapy Evidence Database score = 5.4) were included, with 7 contributing to quantitative synthesis. Only trials reporting isokinetic muscle strength, jumping performance, and aerobic capacity outcomes provided sufficient data for meta-analysis. Protocols commonly involved 10 to 14 uphill sprints of 30 seconds at a ~10% gradient, performed 2 to 3 times weekly over 2 to 8 weeks. Narrative synthesis showed improvements in running economy, repeated sprint ability, and aerobic outcomes such as ventilatory threshold and lactate clearance. However, meta-analysis revealed no significant effects on isokinetic knee strength (SMD = 0.09, 95% CI = -0.41 to 0.59, P = .73; I2 = 0%), jumping performance (SMD = 0.15, 95% CI = -0.39 to 0.70, P = .59; I2 = 0%), or aerobic capacity (SMD = 0.31, 95% CI = -0.11 to 0.74, P = .15; I2 = 0%). Although statistical heterogeneity was low, the overall certainty of the evidence remained low because of the limited number of trials contributing to each meta-analysis, small sample sizes, and variability in intervention protocols and comparator conditions. Uphill running may induce favorable neuromuscular and aerobic adaptations, but meta-analysis findings did not confirm significant pooled effects on knee strength, jump performance, or aerobic outcomes. Future high-quality RCTs with standardized gradients, sufficient sample sizes, and longer durations are needed.