Automated research refresh updated the product evidence set.
Before: Evidence 83 · Safety 72 · Effectiveness 79 · Confidence 69
After: Evidence 73 · Safety 72 · Effectiveness 68 · Confidence 68
Yes4All Cast Iron Kettlebell, Strength Training Kettlebells 5-80 Lb (5,10,15,20,25,30,35,40,45,50,60,70,80 Lb) for Full Body Workout, Push up, Strength Training - Single & Kettlebell Set of 2 for Men
Adjustable hand grip trainer for progressive resistance built for grip, wrist, and forearm training.
Direct product evidence5 papers indexed · 5 claims mapped
Resar evidence panel
0–100 · cited research only
Evidence Score
73
Strong
Safety Score
72
Strong
Effectiveness Score
68
Good
Research Confidence
68
Good
Product Fit Score
60
Good
Bottom line
Moderate evidence (Strong) — promising research, but read the caveats before buying.
Product fit is weaker — dose, price, or practical use may not align with what studies tested.
Evidence Score
73
Strong
Price
$12.60
Resar may earn an affiliate commission on this purchase. Commissions never change scores — see our affiliate disclosure and conflicts policy. Scores reflect cited research, not medical advice.
Compare others in FitnessTop research
The strongest studies behind this product
Ranked by evidence hierarchy and how closely each study matches this product. Start with the strongest study, then read down. Every claim needs a trail.
Strongest studySupporting evidence86% relevance
Effects of supervised high-intensity hardstyle kettlebell training on grip strength and health-related physical fitness in insufficiently active older adults: The BELL pragmatic controlled trial
Other · 2021
What the research shows
Mean increase in grip strength: +7.1 kg (right), +6.3 kg (left).
Direct product evidenceRead study
2345
Supporting evidence80% relevance
Effects of Wrist Stability Training Combined with Grip Strength Exercise on Pain and Function in Patients with Nonspecific Chronic Wrist Pain
Other · Medicina · 2024
Direct product evidence
Indirect evidence74% relevance
The Effect of Forearm Position, Hand Dominance, and Gender on Hand Grip Strength in Healthy Young Adults
Other · 2026
Category-level evidence
Indirect evidence68% relevance
Grip Strength: An Indispensable Biomarker For Older Adults
Other · Clinical Interventions in Aging · 2019
Category-level evidence
Indirect evidence62% relevance
The Longitudinal Associations of Handgrip Strength and Cognitive Function in Aging Americans
Other · Journal of the American Medical Directors Association · 2020
Category-level evidence
Scores reflect these cited studies, not medical advice. Expand the full evidence detail below for protocols, dose context, and reported side effects.
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Claim ledger
Every claim, mapped to its source
Each product claim below is tied to a specific paper with study type, match strength, and limitations. Nothing here is medical advice — it is a research trail you can audit.
Claim match reflects how closely a specific paper supports this benefit — not AI confidence or medical certainty.
ClaimEvidence directnessMatchStudy type
Full evidence detail
Study-by-study breakdown
Each paper below is ranked for this listing. Start with the highest match, then expand any study for a plain-language readout.
How to read this section
- Match % - how closely the study matches this product (not overall scientific quality).
- Evidence type - study design (RCT, review, etc.) and whether it is direct, category-level, or indirect.
- What it found - short summary and quoted extract from the paper metadata. Not medical advice.
Direct product evidenceThis study closely matches this product or its active ingredient.
In plain language
Sixteen men and sixteen women (≈68 yr) completed a 3‑month supervised hardstyle kettlebell program after a 3‑month control period. Grip strength increased by 7.1 kg (right) and 6.3 kg (left) (p < 0.001). Additional benefits included improved walking distance, leg strength, and reduced resting heart rate. [1]
What the study reported
Verified extract — not AI generated
“Mean increase in grip strength: +7.1 kg (right), +6.3 kg (left).”
How it was used
Supervised sessions 3 times/week for 12 weeks; progressive hardstyle kettlebell loads averaging 100,977 kg total across participants.
Side effects noted
Four non‑serious adverse events reported; no major injuries.
Caveats
Small sample (n=32), short‑term (12 weeks), limited to insufficiently active older adults; no long‑term follow‑up.
Transparency
Score history
Human review is pending for this listing.
Automated research refresh updated the product evidence set.
Before: Evidence 69 · Safety 72 · Effectiveness 63 · Confidence 70
After: Evidence 83 · Safety 72 · Effectiveness 79 · Confidence 69
Reviews
Shopper feedback
4.7
average rating
9,260 Amazon reviews were available from the listing metadata.