But there’s growing evidence from Baar’s lab and others’ that the full RICE approach may, in fact, impede recovery, not speed it.

Instead, newer research about the microscopic environment inside sore, injured joints and tissues suggests moving and exercising in the right ways is key to recovery. Some of the researchers have even coined a new acronym for how best to treat these injuries. It’s all about, they say, PEACE and LOVE.

What happens when you hurt yourself?

Most experts agree the RICE acronym first appeared in the 1978 bestseller The Sports Medicine Book by physician Gabe Mirkin. It caught on fast, because it made such intuitive sense. Don’t move or use a sore joint or limb, numb it with ice and anti-inflammatories, and reduce any swelling with compression and elevation.

The overriding concern with this approach was to fight the sudden flare of inflammation that accompanies injuries. It was thought to exacerbate tissue damage.

But science has reconsidered the role of acute inflammation since 1978. “Our bodies evolved the inflammatory response to kick-start the healing process,” said Jean-François Esculier, a physical therapist and clinical associate professor of medicine at the University of British Columbia in Kelowna who studies and treats sports injuries.

Studies show that inflammation begins almost immediately after an acute soft-tissue injury, as nearby blood vessels widen to increase blood flow to the stricken area. The blood carries a host of immune cells that rapidly start to mop up and remove cellular debris caused by the injury.

You also get a rush of prostaglandins, a hormone-like substance that triggers pain and swelling but also, in mouse experiments, stimulates nearby stem cells to start dividing and creating new muscle or collagen cells to repair and replace injured tissue.

The effects of ice and ibuprofen

Aspects of this inflammatory process can cease or slow if you ice the injury or take ibuprofen.

“Icing constricts blood flow,” Esculier said, so fewer immune cells reach the injury, and the composition of those cells may change.

In a 2021 mouse study, some animals with slight muscle damage wore tiny ice packs over the injury; others didn’t. In the un-iced legs, a host of inflammatory cells appeared quickly, cleared debris and disappeared when anti-inflammatory cells moved in, with full tissue recovery in less than two weeks.

In the iced legs, immune cells arrived later, in smaller numbers and removed less debris. Healing remained incomplete after two weeks.

Any delay in healing in people is probably slight, though, said Justin Shaginaw, a physical therapist with Penn Sports Medicine in Philadelphia and former athletic trainer for the US men’s soccer team. “If pain is significant enough, and ice helps,” he said, “use it.”

Ibuprofen also affects the inflammatory response, Esculier said, by blunting the release of prostaglandins and reducing pain. But fewer prostaglandins can mean fewer stem cells near the injury get the message to fire up and start making replacement cells.

As a result, ibuprofen, like icing, “can interfere and slow the healing process,” said Stuart Warden, a physical therapist and associate dean for research at Indiana University Indianapolis, who has long studied athletes and injuries.

If you need pain relief, consider acetaminophen, the active ingredient in paracetamol, which is not an anti-inflammatory, Esculier said.

What’s wrong with too much rest?

Probably the greatest problem with RICE, though, most experts agree, is the R – rest.

It’s “often misinterpreted as ‘put your feet up and do nothing,’” Warden said.

But immobility causes rapid loss of muscle mass and tendon and ligament strength, Baar said, not only around the injured area but in the rest of the limb. When his group attached 3D-printed casts to rodents’ legs to keep them still, the animals began losing muscle mass within days.

This decline happens in part because immobility stills the biochemical signals that otherwise stream through muscle cells with every contraction, cuing the cells to adapt and grow stronger, Esculier said.

The more strength and flexibility you lose with immobility, “the longer it takes to fully recover,” Shaginaw said.

Staying off some injuries, such as a badly sprained ankle or sore knee, may be necessary and advisable for a day or even two, Warden said. (If you can’t bear weight on a joint after more than a day, you should probably see a doctor.)

“Movement is important” for healing after an injury, Baar said, and the sooner, the better. But it needs to be the right kind of movement.

Gentle exercise, as early as possible

“You need low-load, long-duration” exercise, Baar said, that doesn’t place too much tension on the injury but gets some force moving through the entire affected tissues. By slightly activating muscles in the injured area, gentle movement helps initiate healing there and avoid scarring, which can permanently weaken damaged tissue.

Sketch, for instance, the alphabet in the air with your foot after an ankle sprain, he said. Start as soon as possible after the injury, preferably within hours or even minutes, if you can. Repeat frequently that day and the next.

Or push with your affected limb against a fixed object, Warden said, such as a wall. This kind of movement causes what are known as isometric contractions, where a muscle contracts without lengthening or stretching, avoiding further straining torn or twisted tissues.

Skip fast, jerky moves, Baar said.

If your injury involves a leg, start walking as soon as you can, Warden said. If you can’t bear full weight, use crutches, but “walk normally,” he said. “Don’t limp.”

A role for PEACE and LOVE

Even Mirkin eventually changed his mind about RICE, Esculier pointed out. In a 2015 post on his personal website, Mirkin wrote that “now it appears that both Ice and complete Rest may delay healing, instead of helping”.

So, in 2019, Esculier and his colleague Blaise DuBois proposed a new protocol and related acronyms for dealing with an injury, PEACE and LOVE, which stand for:

The acronyms may be slightly laboured – “there are too many e’s,” Warden said – but the protocols’ fundamental advice and that of most experts boils down to a few simple messages that, if followed, may have you back to full activity faster and more fully than if you rely solely on RICE.