Optimising the effect of exercise training: identifying physiological and genetic factors that determine muscle & cardiovascular adaptation to exercise training

The beneficial effects of exercise training are well known. Training improves the size and function of the cardiovascular system and reduces the risk for cardiovascular disease. Furthermore, training also leads to better and stronger muscles and tendons. However, recent work found large inter-individual variability in adaptation, with some subjects reporting no change or even a decline in fitness, cardiovascular health and muscle function. These remarkable findings raise several questions that have clinical importance.
In this project, the PhD-student will focus on 3 important questions that eventually help to understand the large heterogeneity in adaptation to exercise training. Understanding the reasons for this heterogeneity in training response may give insights into the mechanisms controlling these adaptations. More importantly, and clinically relevant, this information will form a crucial step towards personalised exercise prescription and optimise the strong effects of exercise training, especially since a low responder to one type of exercise might be a high responder to a different type. Accordingly, this PhD-project contributes to the concept of ‘exercise is medicine’.

Question 1: Does this mean that these individuals adopt the wrong type?
Some people may benefit more from endurance training, whilst others demonstrate large improvements after resistance training. First, we will document the inter-individual variability in adaptation. Secondly, to better understand the heterogeneity in adaptation to training, the student will compare the magnitude of cardiovascular adaptations to both types of training within subjects. Finally, the student will compare the magnitude of adaptations in cardiovascular and muscle/tendon function for a type of training, to assess if cardiovascular and muscle/tendon adaptations match.

Question 2: What stimuli during an acute bout of exercise predict subsequent adaptation? [1]
A widely accepted physiological ‘rule’ is that improvement in strength/function is achieved by changing the homeostasis of a system. This could mean for exercise training that improvement in cardiovascular function after training depends on the acute changes in blood flow during exercise and/or vascular function after exercise. This topic will be examined in detail in this PhD-project.

Question 3: Are there genetic profiles that contribute to the lack of adaptation to training?
The magnitude of cardiovascular or muscle/tendon adaptation to exercise training may be associated with specific gene polymorphisms, or variants, whilst the gene polymorphisms for cardiovascular adaptation may differ from those involved in adaptations of the muscles/tendons. By identifying specific gene polymorphisms that contribute to adaptation, we will be able to understand why some subjects respond more to exercise training, but also why endurance training may be more effective than resistance training within subjects (and vice versa).