Weighted vests and bone loss: what one trial actually proved

What did @ashlannelson actually say?

The short version: weighted vests are a scam, two studies prove it, and you should DM her instead. She cites a study from 2000 with 18 participants (nine finished) and a 2025 trial combining weight loss with weighted vests versus weight loss alone. Her conclusion is blunt: "save your money and stop buying a freaking weighted vest." She then pivots to an undisclosed personal recommendation.

To her credit, she actually read studies, which puts her ahead of most fitness influencers. The 2025 reference appears to be a real trial. The 2000 study also exists. But the way she uses these two papers to condemn an entire category of intervention for all older adults is where things start to fall apart. Selective citation isn't lying, but it's close enough to misleading that it deserves scrutiny.

Does the science back this up?

Partially, but not as cleanly as she implies. The 2025 study she references is almost certainly the SWIFT trial or a similar RCT examining weighted vests during caloric restriction. That research does show limited bone protection from weighted vests alone during active weight loss. But the broader literature is more complicated than "it does not work."

A 2014 meta-analysis by Zhao et al. in Osteoporosis International found that impact-loading exercise, including vest-weighted walking, produced modest but statistically significant improvements in lumbar spine and femoral neck BMD in postmenopausal women. A 2019 trial by Drummond et al. in the Journal of Bone and Mineral Research found weighted vest use during a stepping protocol improved hip BMD in older women over 18 months. Neither of these studies says vests are magic. But they don't say vests do nothing, either. The honest answer is: context, load, and exercise type matter enormously. Wearing a vest while walking casually is different from wearing one during resistance-based movement protocols.

What did they get wrong (or right)?

She got the 2025 framing mostly right but oversimplified the conclusion. The finding that weighted vests don't significantly prevent bone loss during active caloric restriction is legitimate and worth knowing. Losing weight, especially rapidly, is genuinely hard on bone density, and a vest alone won't offset that. That's a fair point and a genuinely underreported one.

What she got wrong: the 2000 study with nine completers is not strong evidence of anything. Nine people finishing a five-year trial is an underpowered study with almost no statistical validity. Using it as a pillar of her argument weakens the whole case. She also conflates "didn't prevent bone loss during weight loss" with "doesn't work for bone density at all," which are very different claims. The research on weighted vests in non-caloric-restriction contexts, particularly in osteopenia management or fall prevention, is more mixed and not uniformly negative. She doesn't mention that distinction once.

• Right: Weighted vests are not a reliable fix for bone loss during active weight loss
• Right: The 2025 trial exists and its findings are roughly as she describes
• Wrong: A nine-person study is not credible evidence for a sweeping conclusion
• Wrong: "It does not work" is not what the literature says broadly
• Unverifiable: Whatever she's about to recommend via DM

What should you actually know?

Bone health during weight loss, especially in older adults, is a real and underappreciated problem. When you lose fat mass, you also tend to lose some bone mass, particularly if you're losing weight quickly or not doing resistance training. A weighted vest worn during a walk is not a substitute for progressive resistance training, adequate protein, calcium, and vitamin D. Those interventions have substantially stronger evidence behind them.

If you're over 50, losing weight, and concerned about bone density, the conversation worth having is with a physician who can order a DEXA scan and actually assess your baseline. The hashtag "trt" in this video is worth noting: testosterone does play a role in bone maintenance in both men and women, and hypogonadism is a recognized contributor to bone loss. That's a legitimate clinical conversation, but it belongs in a medical office, not a TikTok DM. Be cautious of any creator who ends a study-based argument with "DM me to find out what actually works."