Endpoint
Lower-body muscular strength (pooled composite)
CAT:outcome/lower-body-strength-compositereported in standardised mean difference (SMD)4 findings from 2 compounds
What moved it
How to read these marks4 findings · 2 compounds · 2 null · by evidence strength
| Compound | Direction | Findings | Strongest evidence |
|---|---|---|---|
| caffeine | no effect | 2 | Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers. |
| creatine | up | 2 | Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers. |
Reported to move it
2 findings
creatine — increases
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.Findingreplicated ×1“In comparison with a placebo, creatine supplementation combined with resistance training significantly increased upper-body (WMD = 4.43 kg, p < 0.001) and lower-body strength (WMD = 11.35 kg, p < 0.001).”
Quoted verbatim from Effects of Creatine Supplementation and Resistance Training on Muscle Strength Gains in Adults <50 Years of Age: A Systematic Review and Meta-Analysis.. - Study
- meta-analysis
- Population
- adults <50 years of age undertaking resistance training
Effects of Creatine Supplementation and Resistance Training on Muscle Strength Gains in Adults <50 Years of Age: A Systematic Review and Meta-Analysis.2024PMID:39519498An author is affiliated with a producerPermalink
creatine — increases
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.Findingreplicated ×1“Compared with resistance training alone (RT), resistance training plus creatine (RT + CR) produced significant increases in upper-body strength (g = 0.54, p < 0.001), lower-body strength (g = 0.55, p < 0.001), lean mass (g = 0.30, p < 0.001), and body mass (g = 0.12, p = 0.04), and a significant reduction in body-fat percentage (g = -0.14, p = 0.02).”
Quoted verbatim from Resistance training combined with creatine supplementation: a three-level meta-analysis of multidimensional outcomes from strength enhancement to body composition remodeling.. - Study
- meta-analysis
- Population
- Resistance-trained adults; three-level meta-analysis of 63 RCTs (n = 1489); resistance training given to both arms
Effect 0.55 standardised mean difference
Resistance training combined with creatine supplementation: a three-level meta-analysis of multidimensional outcomes from strength enhancement to body composition remodeling.2026PMID:42765482Permalink
Measured, no effect detected
2 findings
caffeine — no detected effect on
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.FindingNull resultreplicated ×1“A subgroup analysis indicated that caffeine significantly improves upper (SMD = 0.21; 95% CI: 0.02, 0.39; p = 0.026; Fig. 3) but not lower body strength (SMD = 0.15; 95% CI: -0.05, 0.34; p = 0.147; Fig. 4).”
Quoted verbatim from Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis.. - Study
- meta-analysis
- Dose
- Acute pre-exercise ingestion (capsule, liquid or gel), mean 4.8 mg/kg, range 0.9-6 mg/kg, 45-60 min before testing
- Population
- Healthy adolescent and young-adult participants, trained and untrained, of both sexes; LOWER-BODY SUBGROUP of the pooled 1RM maximal-strength analysis, not the overall estimate. Constituent tests: back squat, leg press.
Effect 0.15 standardised mean difference, 95% CI -0.05 to 0.34
Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis.2018PMID:29527137Permalink
caffeine — no detected effect on
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.FindingNull resultreplicated ×1“In a subgroup analysis that considered only lower-body 1RM tests, there was no significant difference between caffeine and placebo (SMD: 0.16; 95% CI: −0.03, 0.35; p = 0.109; I2 = 0%).”
Quoted verbatim from Ergogenic Effects of Acute Caffeine Intake on Muscular Endurance and Muscular Strength in Women: A Meta-Analysis.. - Study
- meta-analysis
- Population
- Healthy adult women; subgroup analysis restricted to lower-body 1RM tests (squat, leg press, knee extension), not the overall estimate
Effect 0.16 standardised mean difference, 95% CI -0.03 to 0.35
Ergogenic Effects of Acute Caffeine Intake on Muscular Endurance and Muscular Strength in Women: A Meta-Analysis.2021PMID:34072182Permalink
How it is measured
Meta-analytic aggregate of lower-limb strength across whichever tests the primary trials used — back squat, leg press, knee extension, isokinetic knee torque — reported as a standardised mean difference, or in kilograms where the review pooled a common test. The constituent tests are listed with each finding.
Sources cited
4 papers
- Subject
- lower-body muscular strength (pooled composite)
- Findings
- 4
- Papers
- 4
Resistance training combined with creatine supplementation: a three-level meta-analysis of multidimensional outcomes from strength enhancement to body composition remodeling.record2026PMID:427654821 finding
Effects of Creatine Supplementation and Resistance Training on Muscle Strength Gains in Adults <50 Years of Age: A Systematic Review and Meta-Analysis.record2024PMID:395194981 finding
Ergogenic Effects of Acute Caffeine Intake on Muscular Endurance and Muscular Strength in Women: A Meta-Analysis.record2021PMID:340721821 finding
Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis.record2018PMID:295271371 finding