I used to see a 40-ish year old man with severe dilated cardiomyopathy (here's a typical chest xray). His ejection fraction was all of 22% and consequently he felt exhausted and breathless most of the time.
He'd snorted methamphetamine during most of his young adulthood, which is what ultimately caused the cardiomyopathy. I had a feeling he was still using, so I asked him if he'd relapsed recently. At first he said no, but when I reminded him that meth is heart poison, he finally confessed:
"I feel so crappy every day, I sprinkle a little on my cereal," he said. "Afterwards, I don't feel so tired."
Right. This falls under the category of Really Bad Ideas.