Shilajit for Muscle Fatigue: Does It Really Work?

observational-study PMID: 30728074

Quick Summary: A study found that taking a specific type of Shilajit (PrimaVie®) helped reduce muscle fatigue and strength loss in active men after exercise. The higher dose of Shilajit (500mg) showed the best results.

What The Research Found

This study looked at how Shilajit affects muscle strength and fatigue. Researchers found that men who took a higher dose of Shilajit (500mg per day) for 8 weeks experienced less muscle strength decline after exercise compared to those who took a lower dose or a placebo (a sugar pill). The higher dose group also showed signs of improved collagen metabolism, which is important for muscle recovery.

Study Details

Who was studied: 63 healthy, active men in their early 20s.

How long: The study lasted for 8 weeks.

What they took: Participants were divided into three groups:

High-dose Shilajit (500mg per day)
Low-dose Shilajit (250mg per day)
Placebo (a pill with no active ingredients)

What This Means For You

If you're an active person, this research suggests that Shilajit might help you:

Reduce muscle fatigue: You might feel less tired after workouts.

Maintain strength: You might experience less strength loss after exercise.

Improve recovery: The study hints at better muscle recovery due to improved collagen metabolism.

Important: The study used a specific type of Shilajit called PrimaVie®. The results may not be the same with other brands or types of Shilajit.

Study Limitations

Limited Group: The study only included young, active men. The results may not apply to women, older adults, or highly trained athletes.

Short-Term: The study lasted only 8 weeks. We don't know the long-term effects of Shilajit.

Dosage Matters: Only the higher dose (500mg) showed significant benefits. The lower dose (250mg) didn't have a noticeable effect.

More Research Needed: The study didn't explain exactly how Shilajit works to reduce fatigue.

Key Findings

Shilajit supplementation at 500 mg/day significantly reduced fatigue-induced declines in maximal voluntary isometric contraction (MVIC) strength and serum hydroxyproline (HYP) levels in recreationally active men. High-dose Shilajit (500 mg) resulted in an 8.9% decline in MVIC post-supplementation compared to 17.0% (low dose, 250 mg) and 16.0% (placebo), with statistically significant differences between high-dose and both lower-dose groups (p = 0.022 and p = 0.044, respectively). Serum HYP levels, a biomarker of collagen metabolism, were significantly higher in the high-dose group (1.5 μg/mL) post-supplementation versus low-dose (1.1 μg/mL) and placebo (1.0 μg/mL) groups (p = 0.003).

Study Design

This 2019 randomized, double-blind, placebo-controlled observational study involved 63 recreationally active men (mean ± SD: 21.2 ± 2.4 years, 83.1 ± 12.7 kg, 179.8 ± 6.3 cm). Participants were stratified into high-dose, low-dose, or placebo groups (n = 21 each). Pre- and post-supplementation testing included MVIC assessments and isokinetic leg extensions at 180°·s⁻¹. Outcomes were analyzed for the upper 50th percentile of responders to isolate effects in individuals with higher baseline variability.

Dosage & Administration

Shilajit (PrimaVie®) was administered orally at 500 mg/day (high dose) or 250 mg/day (low dose) for 8 weeks. Placebo groups received identical capsules without active ingredients. Supplementation was standardized to ensure consistency in timing and dosage.

Results & Efficacy

MVIC Decline: High-dose Shilajit reduced strength loss by 8.9% (±2.3%) post-exercise compared to low-dose (17.0% ± 2.4%, p = 0.022) and placebo (16.0% ± 2.4%, p = 0.044).
Serum HYP: High-dose group showed elevated baseline HYP (1.5 ± 0.3 μg/mL) versus low-dose (1.1 ± 0.3 μg/mL) and placebo (1.0 ± 0.3 μg/mL, p = 0.003), suggesting enhanced collagen turnover.
Dose Dependency: Only the high-dose group demonstrated significant benefits; low-dose effects were comparable to placebo (p = 0.774).

Limitations

Population Specificity: Results apply only to recreationally active young men; generalizability to women, older adults, or athletes is unproven.
Subgroup Analysis: Findings were limited to the upper 50th percentile of responders, potentially reducing broad applicability.
Short Duration: The 8-week intervention period does not address long-term efficacy or safety.
Mechanistic Gaps: The study did not explore the biological pathways linking Shilajit to HYP changes or fatigue resistance.

Clinical Relevance

For supplement users, 500 mg/day of Shilajit may mitigate muscle strength loss during high-intensity exercise and support collagen metabolism, as indicated by elevated HYP. However, 250 mg/day showed no benefit, highlighting dose dependency. These findings could inform strategies for athletes or individuals experiencing exercise-induced fatigue, though further research is needed to confirm effects in diverse populations and real-world settings. The study underscores Shilajit’s potential as an ergogenic aid but does not establish optimal usage protocols beyond the 8-week timeframe tested.

Note: This analysis is restricted to the 2019 study (PMID 30728074) and does not incorporate external evidence. All conclusions reflect the original authors’ interpretations.