Active Lives, Stronger Bodies: The Role of Exercise in Maintaining Fat-Free Mass Across Ages
Exploring the effects of staying in shape earlier and later in life.
It's no secret that staying in shape preserves not just our physical appearance, but also our overall health and vitality as we age. The benefits of regular physical activity extend far beyond the aesthetic; they play a crucial role in maintaining fat-free mass, which is essential for optimal body function and longevity. As we navigate through life, from childhood to our golden years, the choices we make about how active we are can significantly influence our muscle mass and, consequently, our quality of life.
This study investigated the relationship between physical activity (PA) and fat-free mass (FFM) across different age groups, highlighting the importance of lifelong physical activity for safeguarding our health.
Key Points
Study Background and Objectives
The research aims to understand how physical activity influences fat-free mass during growth and in later life.
FFM is an indicator of muscle mass, which is essential for overall health, particularly in preventing conditions like sarcopenia (age-related muscle loss).
Methods
The study analysed data from 2000 participants aged 3 to 96 years, using the International Atomic Energy Agency Doubly Labeled Water database.
Total energy expenditure (TEE) and resting energy expenditure (REE) were measured to calculate physical activity level (PAL = TEE/REE).
FFM was assessed using isotope dilution methods.
Results
Determinants of FFM: PAL was identified as a significant determinant of body composition at all ages. For participants under 18 years, models explained 76% to 85% of the variation in FFM based on age, fat mass (FM), and PAL. Over 18 years, models explained 32% and 47% of the variation in FFM in females and males, respectively.
Increased FFM with Higher PA:
In younger participants (<18 years), very active individuals (PAL = 2.0) had significantly higher FFM compared to sedentary peers (PAL = 1.5).
At age 18, mean FFM differences were approximately 3.6 kg for females and 4.4 kg for males between active and sedentary individuals.
Age-Related Decline: Peak FFM occurs around age 30, after which there is a gradual decline. The study indicates that while higher PA levels can help maintain FFM in older adults, they may not completely prevent age-related losses.
Gender Differences: Females generally exhibited higher fat mass than males at all ages, influencing overall body composition.
