Scientists Linked Low Muscle Strength To A Higher Risk Of Infection

We tend to think about muscle in terms of what it lets us do. It helps us lift heavier weights, carry groceries, get up off the floor, and stay mobile as we get older. But muscle isn't just sitting there waiting for you to use it.

Skeletal muscle is metabolically active tissue that communicates with other systems throughout the body. It plays a role in blood sugar regulation, inflammation, metabolism, and, perhaps less obviously, immune function.

The prospective study included 458,332 adults from the UK Biobank who were followed for a median of 12.5 years.

At the beginning of the study, researchers assessed participants' muscle mass, strength, and physical performance. They then grouped them based on whether they had no sarcopenia, probable sarcopenia, or confirmed sarcopenia.

Sarcopenia is the progressive loss of muscle mass and strength that becomes more common with age. While we often associate it with frailty in older adults, researchers are learning that losing muscle can have consequences throughout the body.

A pretty clear pattern emerged: The less muscle participants had, the greater their long-term risk of infection.

Compared with people without sarcopenia, those with probable sarcopenia had an 18% higher risk of developing infections or infectious diseases. For people with confirmed sarcopenia, that jumped to 34% higher risk.

Importantly, both handgrip strength and muscle mass were independently associated with infection risk. The relationship also remained after researchers accounted for factors like age, sex, socioeconomic status, lifestyle, and existing health conditions.

One of the most interesting things we've learned about skeletal muscle is that it's not simply a movement organ. It also functions almost like an endocrine organ, releasing signaling molecules called myokines that communicate with tissues throughout the body.

Some of these myokines help regulate inflammation and influence how immune cells function. Muscle also acts as a reserve of amino acids, including those the body can draw on during periods of physical stress or illness. When you're fighting an infection and your immune system suddenly needs more resources, having that reserve matters.

The nice thing is, you don't need an elaborate training routine to start protecting the muscle you have. Strength training a couple of times a week can go a long way, whether you're lifting weights at the gym, using resistance bands at home, or doing bodyweight exercises. What matters most is that your muscles are regularly being challenged.

And you can't talk about maintaining muscle without talking about protein. Getting enough throughout the day gives your body the amino acids it needs to repair and build muscle after those workouts. Spreading protein across your meals can also help make sure your muscles are getting that building material more consistently.

We tend to think of muscle loss as something to worry about much later in life, but maintaining muscle gets harder as we age. That makes building and protecting it now one of those habits that can pay off for decades.

We often talk about "supporting immunity" through what we eat, how much we sleep, or the supplements we take. This research adds another habit to that conversation: keeping our muscles strong.