In general this is a study with few risks. The weight vests used in this experiment are in daily use by thousands of people during exercise . During the experiment with medical students only one of the students experienced an adverse event. This student experienced mild dizziness which subsided within a few minutes after removing the weight vest and sitting down. To further minimize the risks in our future study the investigatorshave decided to include only healthy research subjects consuming no medications. The investigators will also have medically trained personnel available during the study and perform it in close vicinity to the Sahlgrenska University Hospital.