My father had been hospitalized several times in recent months and lost significant leg strength with each bout. Lately, he was put on hospice due to heart failure, and his legs ceased to be of any use after about two weeks. After living a great life, he sadly passed on March first, 2023, at 93, three days before his 94th birthday. He had a massive heart attack when he was about 52. His Funeral is today at 1:30. I wrote about why he had a bad heart here. His heart was so damaged they gave him poor odds of survival. They told him he would die young, even if he survived the next few weeks. They told him not to exert himself. He complied initially but then started lifting weights and walking. He regained his youthful vitality, which kept him alive for the next 42 years. This post explains why. He taught me many things. One of his last lessons was about being confined to bed and its many downsides, even if it is sometimes unavoidable. This post is dedicated to him.

We draw upon the muscle mass of the legs with illness; they are vital for maintaining our metabolic health. I always say muscle is medicine because studies show that the more you have, the better your odds of survival from illness and injury, especially with age. Here's why:

After age 30, adults lose 3-8% of their muscle mass per decade. The condition is called sarcopenia, and this post I wrote a few years ago can tell you more about it. It starts slowly, and the rate of muscle loss can reach 15% per year in later years. It progresses until 50% of muscle mass is gone by our seventies. A systematic review published in 2018 found that 41% of nursing home residents have sarcopenia, four times higher than the overall prevalence. 1 These studies and others show that sarcopenia leads to more hospitalizations, a greater likelihood of nursing home care, and a generally lower quality of life. 

Hospitalizations also cause rapid muscle loss, especially in the legs, so sarcopenia can lead to increased hospitalization, which can lead to abrupt muscle loss, and on and on. What I just described is known as a feedback loop. Once the patient can't walk, their muscle mass quickly diminishes, and health rapidly declines until death. In other words, muscle loss and hospitalizations feed into each other, causing rapid downward spirals in health, ultimately leading to death. Additionally, bed rest damages the patients' metabolism, another risk factor for diabetes, obesity, and early death. This post will cover leg muscle wasting with hospital stays and what to do about it.

As I just said, with advancing age, it becomes increasingly likely that even a brief period of bed rest could initiate a serious decline in muscle strength, and a tipping point to rapid death may occur. A 2016 study of ten healthy 23-year-olds on bed rest for ten days showed their leg strength decreased by 6 to 10 percent. Even worse, their insulin sensitivity, which leads to diabetes, decreased by 29% on average. 2 Data from a 2007 study on bed rest in older adults suggested that the loss of lean tissue in healthy older adults during bed rest far exceeded the losses experienced by younger patients. 3 Survivors of critical illness experience significant skeletal muscle weakness and physical disability, which can persist for at least five years. 4

There are several explanations for why the legs are the primary target. Standing activates the leg muscles, so laying down causes almost complete disuse. The arms can still function close to normal when in bed, so they are spared. Muscle disuse causes atrophy. Studies demonstrate that the main cause is a lack of protein synthesis, even in high-protein diets. 2 This explanation lends credence to the adage, use it or lose it. 

Another explanation is that the stress hormone cortisol also contributes to losing strength and muscle tissue. Cortisol causes tissue breakdown and can often be high in hospitalized patients for obvious reasons. A 2006 study showed that patients with high cortisol suffered three times more muscle loss than those with normal levels. 5

Loss of strength is worse than the loss of muscle tissue. Strength loss occurs at twice the rate in older patients and leads to loss of functional capacity. In older adults, the loss can exceed 11%. 6,7 Functional capacity refers to one's ability to perform tasks associated with daily life. We are in trouble if we can't walk around the grocery store and carry the packages.

 More needs to be understood about the metabolic changes seen with bed rest. However, impairments in metabolic health following prolonged bed rest include a decline in glucose tolerance and insulin sensitivity, a decrease in resting fat oxidation, an increase in mitochondrial reactive oxygen species production, and a decline in basal metabolic rate. The mitochondria are responsible for energy production through ATP, so it makes sense that inactivating the large muscles of the legs results in less energy production, mitochondrial damage, and, ultimately, insulin resistance. 2 

Bed rest is usually unavoidable, so it is a double-edged sword. Data from studies demonstrate that the losses after one week take twelve weeks of training to undo. 8 Unfortunately, no protocol requiring three months of training after a one-week hospital stay exists, suggesting that repeated lifelong bed rest are equivalent to or worse than normal sarcopenic changes seen with age. I strongly suggest daily resistance training to combat both sarcopenia and bed rest. Unfortunately, the training has to be done when the bed rest is over; however, light activity may still be needed weeks or months after an illness or injury, which may hamper recovery. Haber et al. determined that aerobic exercise, like cycling, induces beneficial changes. In case of inability to exercise, whole-body vibration therapy vastly improves leg strength, knee strength, sit-to-stand performance, and jumping height.

Dietary countermeasures have been studied. Muscle loss in all age groups has been observed despite diets meeting or exceeding the recommended daily allowance (RDA) for protein. Supplements of the essential amino acids have been used, resulting in muscle synthesis remaining unchanged. Notably, leucine is the rate-limiting amino acid for muscle. Therefore, supplementing with it is especially important. 9 

No matter how hard we try, we lose muscle and strength as we age. I know bedrest is unavoidable when gravely ill; however, awareness that this happens is half the battle. Resistance training is a prerequisite for health and longevity. Additionally, remaining active when we can and eating a diet of unprocessed whole foods devoid of processed carbohydrates and processed seed oils like corn or canola is the best way to stay healthy and stave off the effects of sarcopenia and other significant chronic diseases like heart disease, obesity, and diabetes.