Do You Think One Could Faint From Not Eating Or Drinking Much Fluids Before Their Usual And Other Intensive Training Sessions?

Posted on Thu, 3 May 2018

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Thu, 3 May 2018 Answered on

Tue, 30 Apr 2024 Last reviewed on

Question : Our daughter has been a busy University Student for the past 4.5 years. In that time due to long study hours her exercise regime was near non existent. We coached her to join a gym. She had been attending for approx i month and had reached 2 klms a day on the walk treadmill. She was contacted by the Gym she joined to attend a meeting with a Personal Trainer. She was running late due to studying to the wee hours . She did not eat breakfast before she went. She hadn't eaten since the dinner time the night before ( 6 pm) . She went through her usual training session and then the Personal Trainer came along and insisted she do another training session with more intensive activities. Our daughter feinted. She was taken to hospital where they tested sugar ( ok) , undertook a ECG ( ok) and her blood pressure , low just after she feinted, returned to normal. She bounced back quick from her feint. This is the only time she has ever feinted in her life. We believe it was due to the fact she hadn't eaten or drunk much fluid before undertaking double her training session and because she was still working up to a fitness routine, she needed time to get a level of fitness before embarking on more strenuous training exercises. Do you think the feint could have been from not eating or drinking much fluids before not only her usual training but another intensive training session after her usual. ?
As a School Student she ran long distance and short distance and participated in lots of sports and never feinted.

Answered by Dr. Sagar Makode (1 hour later)

Brief Answer:
Likely cause is dehydration and vagal syncope

Detailed Answer:
Hello,
The likely cause in her is dehydration and subsequent vagal activation. This leads to fall in bp, low pulse rate leading to fainting. I guess there is no family history of any cardiac disease or sudden unexplained cardiac death, just to rule out possibility of Hcm. However, she should get one echo done to definitely rule out structural heart disease like HCM. So additionally echo is recommended in her.
In management, she should have gradual escalation of exercise program, plenty of fluids and avoid dehydration. Its better to limit the exercises to mild to moderate level till we get echo done.
Hope this helps you and get back if you have any doubts.

Above answer was peer-reviewed by : Dr. Yogesh D