Dr. Lex Verdijk – Associate Professor

Department of Human Biology

NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University


Prof. Dr. Luc van Loon – Professor of Physiology of Exercise and Nutrition

Department of Human Biology

NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University




The role of physical activity and nutrition in the regulation of age-related loss of muscle mass and function

Our research group is specialized in in vivo human metabolic research, and the main fields of interest include skeletal muscle metabolism, exercise metabolism, sports and clinical nutrition, and aging. Our research aims to increase knowledge that will enable us to define more effective exercise and nutritional interventions to improve health and functional performance in health, disease, and with aging. We study human metabolism on a whole-body, tissue, and cellular level, with skeletal muscle as the main tissue of interest. The use of stable isotope methodology has a special interest in our group. Using this methodology, we have shown that the muscle anabolic response to food ingestion is dependent on the type, dose, and timing of protein intake. Furthermore, we have shown that ageing is associated with a blunted anabolic response to protein ingestion, termed ‘anabolic resistance’, which likely represents a key factor in the age-related loss of muscle mass and function. Importantly, physical activity sensitizes skeletal muscle tissue, thereby facilitating the muscle anabolic response to protein intake. In contrast, physical inactivity (such as with bed rest, immobilization, or a sedentary lifestyle) reduces the anabolic response, thus inducing anabolic resistance. We use the leads from acute and short-term studies to develop more prolonged intervention strategies, combining both exercise and nutritional interventions, aiming to optimize muscle health and function, both in clinical populations and to support overall healthy ageing of our society.

Main aims

  • To elucidate the mechanisms that regulate skeletal muscle metabolism and the skeletal muscle adaptive response to exercise and physical (in)activity
  • To increase our understanding of the mechanisms responsible for the age-related loss of muscle mass and strength, including a sedentary lifestyle and the impact of short, successive periods of muscle disuse following illness, falls, fractures, and/or (elective) surgery
  • To investigate how nutrition and nutritional compounds can alleviate the loss of muscle quality and quantity which is experienced with aging and by many patient populations, and to study how nutrition can support subsequent active rehabilitation.


  • Human intervention studies; exercise and nutrition
  • Stable isotope tracer methodology to study (skeletal muscle) tissue turnover
  • Metabolic biomarkers in blood (digestion/absorption kinetics, amino acid profile, lipid profile, glucose homeostasis, etc)
  • Skeletal muscle phenotyping (muscle biopsies)
  • Body composition / imaging (DXA, CT, MRI)


  • TKI/Health Holland
  • ZonMW
  • Industry