The Effect of Oxygen Supplementation in Training in Heart Failure Patients on Aerobic Performance and Quality of Life

The study population: The study recruited 24 patients with heart failure who came to the cardiac rehabilitation program at Laniado Hospital who met the inclusion criteria. After receiving an explanation of the study, the participants were asked to sign an informed consent form and were randomly divided into 2 training groups, with and without oxygen administration. A sample, using G-power software, medium effect size (0.3), power 0.8 and an error of 0.05 was found to be equal to 24 participants.

Measurement and evaluation tool:

Maximum effort protocol: to assess the maximum aerobic capacity, a graded exercise test was performed on a moving track according to the Bruce protocol. which began by walking at 2.4 km/h and a 10% incline, every three minutes the incline and speed were increased until the subject reported that he/she could not continue any longer. At the end of each step the heart rate was recorded Heart rate and the subjective degree of difficulty according to the Borg scale. The last stage reached by the subject was used to determine multiple values (calculated heart rate and maximum oxygen consumption).

Aerobic submaximal exercise protocol: the test consisted of walking on a track at an incline and speed determined according to the phase corresponding to the Bruce protocol in which the patient reached 80% of the maximum heart rate at the beginning of the training program, the participant was asked to persist in walking until he could not continue at the required pace and reached fatigue. Record the time and distance until the end of the effort.

A submaximal exercise protocol to compare single exercise conditions with and without oxygen: In order to compare the effect of supplementing oxygen in a single exercise some of the participants (n=20) performed a submaximal exercise protocol with and without oxygen in two consecutive sessions and in random order. The tests were performed on a rail at an incline and speed determined according to the phase corresponding to the Bruce protocol in which the patient reached 80% of the heart rate. In the test under oxygen conditions, oxygen supplementation of ~20% (5 liters per minute) was given using oxygen goggles, and in the test under conditions without oxygen supplementation (placebo) room air was given (5 liters per minute) using oxygen goggles. Every three minutes, the heart rate was recorded, the feeling of exertion and the level of lactic acid in the blood, the time and distance that the participants gulped until they reported that they could not continue with the given effort was recorded. The tests were done within 72 hours and in random order.