Nutritious diet is related to higher physical fitness in middle-aged people

A study published in the European Journal of Preventive Cardiology found that a nutritious diet is related to higher physical fitness in middle-aged people. Study author Dr. Michael Mi of Beth Israel Deaconess Medical Center, Boston, US, said, “This study provides some of the strongest and most rigorous data thus far to support the connection that better diets may lead to higher fitness. The improvement in fitness we observed in participants with better diets was similar to the effect of taking 4000 more steps each day.”
Cardiorespiratory fitness measures the body's ability to deliver and utilise oxygen during exercise. It considers the health of several organ systems, including the heart, lungs, blood vessels, and muscles. It is one of the most powerful indicators of health and lifespan. While exercise improves cardiorespiratory fitness, there are disparities in fitness among persons who exercise the same amount, indicating that other factors have a role. A healthy diet has been linked to various health advantages, but it is unknown if it is also linked to fitness.
This study aimed to see if a nutritious diet is related to physical fitness in community-dwelling individuals. The Framingham Heart Study includes 2,380 participants. The average age was 54, and 54% of the participants were female. To determine peak VO2, participants performed a maximal effort cardiopulmonary exercise test on a cycle ergometer.
Dr. Mi said, "In middle-aged adults, healthy dietary patterns were strongly and favourably associated with fitness even after taking habitual activity levels into account. The relationship was similar in women and men, and more pronounced in those under 54 years of age compared to older adults.”
The researchers performed further analyses to discover the potential mechanism linking diet and fitness. They examined the relationship between diet quality, fitness and metabolites, substances produced during digestion and released into the blood during exercise. 201 metabolites (e.g. amino acids) were measured in blood samples collected from a subset of 1,154 study participants. Some 24 metabolites were associated with either poor diet and fitness or favourable diet and fitness after adjusting for the same factors considered in the previous analyses. Dr. Mi said, "Our metabolite data suggest that eating healthily is associated with better metabolic health, which could be one possible way that it leads to improved fitness and ability to exercise.”
He noted limitations, "This was an observational study and we cannot conclude that eating well causes better fitness, or exclude the possibility of a reverse relationship, i.e. that fit individuals choose to eat healthily.”