Acute response to strength training in congenital heart disease

This study is looking for young people aged between 15 and 24 years old. They are interested in two main groups: young people who have been diagnosed with a congenital heart condition (a heart problem they were born with) and a comparison group of healthy young people.

If you have a congenital heart condition, you can take part if your heart condition is considered mild to moderate (doctors call this New York Heart Association class I or II – meaning you don't have discomfort during normal activities, or you might feel some tiredness or breathlessness but not when resting). Healthy participants will be matched to the heart condition group based on their age, sex, and how much exercise they normally do.

You cannot take part if you have certain conditions, such as severe heart problems like very weak heart pumping or very narrow heart valves. You also can't join if you have a history of dangerous heart rhythm problems, or if other health issues (like problems with your lungs, nerves, or bones) stop you from safely doing the required exercise. If you're 15, 16, or 17, your parent or guardian will need to give their permission, and you'll also need to agree yourself.

If you decide to take part, you will have two visits to the University of Exeter. These visits will be at least four days apart but within a 28-day period.

During your first visit, you'll complete some questionnaires, have your body measured (including your height, weight, blood pressure, heart rate, and oxygen levels), and do some muscle strength tests. You'll also do a cycling fitness test while wearing a breathing mask, which helps the researchers find your safe exercise limits. Finally, they'll test your maximum lift for certain strength exercises to set specific weights for your workout.

Your second visit will involve a single, supervised workout session. This includes a 10-minute warm-up, a 10-minute period to get familiar with the exercises, and then about 30 minutes of strength training. You'll do exercises like squats, calf raises, deadlifts, and leg extensions, gradually increasing the weight over three sets. Throughout this session, your heart rate and oxygen levels will be continuously monitored, and your blood pressure will be checked. You'll also fill out short questionnaires about how hard you feel you're working and how much you're enjoying it. After this visit, for the next three days, you'll be asked to do simple check-ins about any muscle soreness you might feel. You'll be asked to avoid any tough exercise for 48 hours before each visit.