What to know about weighted vests in your exercise routine

For years, the military and law enforcement have used weighted vests for conditioning. Today, thanks in part to social media, more regular folks are strapping them on to get more out of their workouts.

Adding a weight-bearing element to your workout can help build bone density, increase functional strength and improve balance. But weighted vests aren’t for everyone, and wearing one that doesn’t fit right or is too heavy can cause problems. Before you slip one on, there are things to consider.

Bones are living structures that respond to pressure and stresses, says Bashir Zikria, the chief of sports medicine at the Johns Hopkins University School of Medicine Department of Orthopedics. So, regular use during weight-bearing activities — such as walking, or body-weight exercises like planks and push-ups — can stimulate bone growth and help slow or prevent bone loss.

“It’s called Wolff’s Law — the more weight you put on the bone, the more it will respond,” Zikria says. “The bones get stronger when you use them and weaker when you don’t.” Like muscles growing with exercise, he says, bones change based on how much pressure or load you put on them.

Kristen M. Beavers, a professor of internal medicine at the Wake Forest University School of Medicine, refers to weighted vests as portable exercise equipment: “They’re a way to sneak loading — adding weight — into everyday activities.”

Mixed research

Research on weighted vests’ effectiveness is mixed.

A study published in June, led by Beavers and other researchers from Wake Forest, enrolled 150 people in their 60s living with obesity. They divided the participants into three groups: those pursuing weight loss alone, weight loss plus daily use of a weighted vest, and weight loss plus resistance training.

Researchers were unable to prove that wearing a weighted vest or participating in resistance training prevented bone loss in older adults seeking to lose weight. All three groups achieved similar, significant weight loss, ranging from 9 to 11.2% of body weight, and a similar rate of significant decreases in hip bone mineral density.

But in another study, conducted by the University of Gothenburg in Sweden and published in May, 51 adults wore either a heavy (11% of body weight) or light (1% of body weight) weighted vest for eight hours a day over five weeks. Ultimately, those who wore the heavy vests showed a decrease in waist circumference and an increase in lean mass in the areas where the loaded weight had been used.

Separately, a 2000 study by the Bone Research Laboratory at Oregon State University followed 18 postmenopausal women for five years. The study found that using a weighted vest in conjunction with jumping exercises prevented significant bone loss in older postmenopausal women.

What to look for

On social media, posts by fitness influencers tout the benefits of a weighted vest or rank their quality, but often don’t include information about what to consider before trying one.

If you plan to use a weighted vest for an extended period, Austin Current, author of “Science of Strength Training: Understand the Anatomy and Physiology to Transform Your Body,” recommends buying a higher-quality brand from a company with a proven track record of good customer service.

“There are plenty of cheap options online with different types of resistance, whether the weights are sandbags or filled with dust or sand from metal shavings,” he says. “That’s not something you want to breathe in if it breaks or starts to leak.” Vests cost anywhere from $30 to $300, but they can sell for as much as $700.

Fit and comfort can influence the likelihood that you will use a weighted vest. Current says to measure yourself based on the vest company’s sizing charts to achieve the best fit for your structure and build. “You want the vest to have a snug fit — waist straps alongside shoulder straps can certainly help individualize your fit,” he adds.

“Resistance through a vest helps preserve muscle, which is crucial for metabolism and long-term fat loss,” Zikria says. He advises starting with 5% to 10% of your body weight — you don’t want it to be too heavy. “Just like anything else, you can get injuries and cartilage damage,” he says.

Current agrees. Starting with a vest that is too heavy can be ambitious but also dangerous. “Too much, too fast is typically a recipe for injury,” Current says. He suggests staying within a weight that allows for a natural gait.

“Long term, your body is very adaptive, like curling a five-pound weight will only be hard at the beginning,” Current says. “As you get stronger, you’re going to notice that [a] five-pound weight becomes very light, and you likely need something heavier to continue to progress.” He suggests using a vest that allows you to increase the weight gradually.

A note of caution

Zikria recommends that people who are overweight or have back problems, as well as those with past knee injuries and cardiac or respiratory histories, stay away from weighted vests. “If someone is really obese, they already have a load on their joints,” he says.

“With a cardiac respiratory history, if it’s not controlled or you haven’t been evaluated, I would hold off because you’re increasing load and output from the heart,” Zikria adds. “When people put extra load on their joints, they can actually cause more significant symptoms … than actually being of benefit.”

How to get started

• Weighted vests can make balance and coordination challenging, so first try them out at home or in a safe place with a carpeted area or a mat. “You want to be in a more controlled environment where it’s a little safer to fall,” Current says.

• If you haven’t been going on walks or you haven’t been active, try walking several times a week without a vest. Current suggests that after a week or two, if you’re not experiencing any joint issues with your feet or with adjusting to your new activity levels, then start using a weighted vest.

• Add weights gradually, starting with 5% of your body weight. “You’re walking distances at faster paces, increasing weight in the vest, something a little bit more progressive in terms of strength training — adding more and more to make it effective,” Current says.

• Limit the time you wear a weighted vest for walking, hiking, running or lifting. Current notes that wearing it outside those time frames will probably not add any benefit and may lead to discomfort and injury.

“A weighted vest should be seen as an addition to your body weight, not a replacement for more traditional and progressive resistance training,” Current says. “If you’re new to strength training and have been performing body weight exercises, adding a weighted vest to your routine can help progress the resistance on all your exercises, which is a great start.”