Skipping Leg Day Could Kill Your Knees
We've all seen those funny images of guys and girls with huge upper bodies and scrawny legs, and we all know that skipping leg day can lead to serious musculature imbalances. But did you know that leg day is necessary for more than just big muscles? In fact, as a recent study discovered, your knees need leg day as much as your leg muscles do.
An early 2017 study found that women with a higher BMI in their legs (less musculature, more body fat) tended to have a higher risk of osteoarthritis than women with a lower BMI (more muscles, less fat). It's a well-known fact that a higher BMI overall can increase the risk of arthritis. After all, more fat equals more weight (pressure) on the joints, leading to faster and potentially uneven wear and tear.
But this study found that leg BMI had a direct influence on knee health. Excessive weight on the legs can lead to faster wear on the knees, increasing the chance of osteoarthritis in the knee joints. Women with less muscle tissue and more fat on their thighs will run the risk of knee problems later in life.
Oddly enough, men with a higher BMI tend to have more muscle tone in their legs than women. The higher BMI also led to an increase in contractile (muscle) tissue in their legs, meaning they tend to have stronger legs than men with a lower leg BMI. The study found that men didn't have a higher risk of osteoarthritis problems even when their leg BMI was higher than normal.
We all know that training our legs is an important part of our fitness routine. After all, our legs do most of the work when we run, cycle, or perform high-intensity training. Strengthening our legs also helps to reduce the impact to our joints, preventing degeneration of the cartilage and reducing the risk of arthritis.
For women, leg day just got a lot more important. After all, if high leg BMI (more fat, less muscle) means a greater risk of arthritis, it's vital for women to spend more time training their legs. Increasing contractile (muscle) tissue in the legs can help to prevent knee osteoarthritis. By doing fat-burning exercises (cardio, HIIT training, general strength training, etc.), women are able to reduce overall BMI, including the fat that naturally gravitates to their legs.
1. Adam G. Culvenor PT, PhD, David T. Felson MD, MPH, Jingbo Niu Dsc, Wolfgang Wirth PhD, Martina Sattler MSc, Torben Dannhauer PhD and Felix Eckstein MD., "Thigh muscle specific strength and the risk of incident knee osteoarthritis: The influence of sex and greater body mass index," Arthritis Care & Research, doi: 10.1002/acr.23182, published online 8 February 2017.