Ron Havenhand: I have been using an Indoor Rower for about 10 years now, two or three times a week, rowing from 3,000 to 20,000 metres in a session, depending on how I feel. I am 61 and do not push things too hard, being content to maintain a reasonable level of fitness and help keep my weight under control at around 82kg. I find I can row at a moderate level of intensity with occasional periodic injections of rowing at a higher level of intensity (up to a minute at a time) without breathing problems. However, if I am out walking, say, and going up a moderate incline or a staircase, I start to feel quite breathless after a few minutes.Any ideas why this might be? I have never had heart problems or anything like that. My blood pressure is slightly raised and controlled through daily medication (which causes no problems at all whilst rowing - my GP is happy with my workout regime). I thought rowing was a good way of maintaining general all-round fitness. I do not do much work on treadmills because my knees will not stand the pounding. Terry O'Neill: High blood pressure is resistance to blood flow and can be caused by various medical conditions. When you exercise there is an increased demand for oxygen in the working muscles and this is carried in the blood. To meet this demand the heart rate increases to pump more blood into the arterial system and if you have high blood pressure then this will aggravate the condition.When you row, the machine is carrying your body weight and so when rowing at a moderate intensity the load is much less than climbing stairs or walking up an incline.Feeling breathless can be either insufficient oxygen getting to the working muscle or a build up of carbon dioxide in the blood or a combination of the two. Next time you are out walking, make a conscious effort to take deep breaths, not just inhaling but also exhaling. Deep inhalation will increase the pressure in the lungs and increase the flow of oxygen into the blood stream. By exhaling, you will clear any residual CO2 out of the lungs but it is important to keep your doctor informed about any developments.