@MacMadame Per the review/editorial in the BMJ, it appears it may actually be harmful to athlete's hearts based on the pharmacology of the drug and its physiological effects. Per other studies in mouse and human/athlete models, it's cardioprotective effects happen only in individuals who have previously experienced myocardial infarction or myocardial ischemia - and I doubt that many athletes have previously had a heart attack.
"Off label" simply means it hasn't been fully approved by a government regulatory body for use in a specific condition/population it's being used for; NOT that there's no studies to back up that use. Journals regularly publish research on "off label" uses. Many things we don't think of as "off label" are technically "off label." Heck, we know morphine treats pain well and have been using it for childhood acute pain since the '70s, but as of 2012 it was still "off-label" to prescribe it to kids - it may still be that way. So saying there are no studies to support its off label use is not misleading - if it's been used off label for 10+ years in such a widespread manner, one would expect at least a couple small studies.