WHY DO WE FEEL GOOD FROM EXERCISING?

We know that we feel good about physical activity, but many questions about why we feel good about exercise remain to be answered. Carl Johan Sundberg, professor of molecular and applied occupational physiology at the Department of Physiology and Pharmacology at KI, researches what actually happens in the body when we exercise and how it contributes to increased health and improved physical functioning.

Regular exercise leads to a lot of things: in skeletal muscle and heart, new blood vessels and mitochondria are formed - the cell's powerhouse. Blood pressure improves. Various inflammatory substances in the blood become less active.

The mechanisms are now being mapped on several levels: from how the presence of different proteins changes and how it affects the body, to the underlying genetic and epigenetic mechanisms.

- Epigenetics, ie the factors that govern how active individual genes should be, has become increasingly interesting. One of the key questions is why different people respond so differently to exercise; and there it is now believed that both genetics and epigenetics are of great importance.

A related question is whether regular exercise leaves epigenetic traces in a muscle? Simply put: will it be easier to train a muscle if it has been trained before? Does it carry any kind of molecular memory, even when the visible traces of a previous workout have disappeared? ( text below from https://ki.se/forskning/epigenetiks-betydelse-for-traning)

The importance of epigenetics for exercise

We know that we feel good about physical activity, but many questions about why we feel good about exercise remain to be answered. Carl Johan Sundberg, professor of molecular and applied occupational physiology at the Department of Physiology and Pharmacology, researches what actually happens in the body when we exercise and how it contributes to increased health and improved physical functioning.

- Regular exercise leads to a lot of things: in skeletal muscle and heart, new blood vessels and mitochondria, the cell's powerhouse, are formed, says Carl Johan Sundberg. Blood pressure improves. Various inflammatory substances in the blood become less active. We want to understand the mechanisms behind such changes.

The mechanisms are mapped on several levels: from how the presence of different proteins changes and how it affects the body, to the underlying genetic and epigenetic mechanisms.

- Epigenetics, ie the factors that govern how active individual genes should be, has become increasingly interesting to us. One of our key questions is why different people respond so differently to exercise; and there we believe that both genetics and epigenetics are of great importance.

A related question is whether regular exercise leaves epigenetic traces in a muscle? Simply put: will it be easier to train a muscle if it has been trained before? Does it carry any kind of molecular memory, even when the visible traces of a previous workout have disappeared?

An ongoing study will hopefully provide answers to that. In the basement below us, subjects first trained the endurance of one leg for three months, and then returned a year later to train both legs. The trials are over; now the results are analyzed.

Training for different patient groups is another important theme in Carl Johan Sundberg's activities. In a current study, he will, together with nursing researchers, study how breast cancer patients during ongoing chemotherapy are affected by different types of exercise.

- Many patients feel unwell as a result of the chemotherapy and some suffer from muscle pain. Physical activity is considered important to reduce discomfort and increase patients' well-being, but today we do not know which exercise is best suited. Nor do we know how much it differs between different patients or how genes are activated.

Another current study is a comparison between interval training and "regular" cardio training.

- At high work intensity, above the lactic acid threshold, the biochemical environment in our muscles is different. We activate other types of muscle fibers that are not normally involved in a normal lukewarm in the training track. This means that the body also responds completely differently to such training.

The Kickstart Team