Being more of a morning person or an evening person can influence your health and muscle strength

Being more active in the morning or afternoon is not just a matter of personal preference. Chronotype, which is each person’s biological tendency to function better at certain times of the day, can play a significant role in preserving muscle mass, as well as its quality and strength, and also in metabolic health. Understanding this relationship can help explain why not everyone responds the same way to the same health routines.

This is one of the conclusions of a scientific review article signed by teams from the University of Barcelona, Bellvitge University Hospital, the Bellvitge Biomedical Research Institute (IDIBELL), the CIBER Area for Diabetes and Associated Metabolic Diseases (CIBERDEM) and the CIBER Area for Pathophysiology of Obesity of Nutrition (CIBEROBN) of the Carlos III Health Institute. The study was led by Professor Pablo M. Garcia-Rovés, from the Department of Physiological Sciences at the UB’s Faculty of Medicine and Health Sciences.

The paper, published in the journal Nutrients, analyses existing scientific evidence on the relationship between the biological clock, lifestyle habits (diet, physical activity and rest) and muscle maintenance, especially in the context of obesity and ageing.

“Chronotype determines how we organize ourselves throughout the day and can indirectly influence key factors for muscle health, such as rest, physical activity and eating schedules,” explains Roberto Barrientos-Salinas, a researcher in the Diabetes and Metabolism Programme at IDIBELL.

When schedules do not align with biology

According to the article, people with an evening chronotype tend to eat later, have less regular sleep patterns, and engage in less structured physical activity. This misalignment between the internal biological clock and social schedules can lead to less healthy lifestyles and impact muscle quality and metabolism.

The research team emphasizes that chronotype is not a matter of willpower or learned habits, but rather an individual biological characteristic determined by genetic and physiological factors.

Muscle, key to independence and healthy ageing

The study highlights the importance of muscle as an essential organ for health: beyond strength or mobility, it plays a decisive role in metabolism and in preventing age-related frailty. In this regard, researchers warn of the risk of sarcopenic obesity, a condition characterized by excess body fat combined with a loss of muscle mass and function, which can compromise quality of life in the long term.

A study analyses the existing scientific evidence on the relationship between the biological clock, habits and muscle maintenance, especially in the context of obesity and ageing.

Towards more personalized recommendations

The paper argues for the need for more personalized and integrated approaches that take into account the time of day when meals are eaten (chrononutrition), the timing of physical activity, and the duration and regularity of sleep.

“Taking chronotype into account can help to better tailor health recommendations and make them more sustainable over time, especially in programmes for weight loss, muscle loss prevention and the promotion of healthy ageing,” says Núria Vilarrasa, head of the Endocrinology and Nutrition Service at Bellvitge Hospital and researcher at IDIBELL and CIBERDEM.

Impact on clinical practice and public health

Although this is a review of the scientific literature, the authors point out that these conclusions may have relevant implications for clinical practice and public health, as they open the door to prevention strategies that are more tailored to each person’s individual characteristics.

“The main objective is for people to be active and avoid a sedentary lifestyle. However, a better understanding of their characteristics and habits allows for the design of more precise interventions that contribute to improving the health and functionality of the population. This approach may be particularly relevant in a society with irregular schedules and a progressively ageing population,” concludes Professor Garcia-Rovés, a member of the MitoHealth research group studying metabolism in obesity and associated diseases, and Serra Húnter associate professor at the UB.

Reference article: Barrientos-Salinas, Roberto et al. “Identifying Chronotype for the Preservation of Muscle Mass, Quality and Strength”. Nutrients, January 2026. DOI: 10.3390/nu18020221.