The recent criticism of sport drinks I’ve heard is that many of them are acidic—mainly for reasons of taste. Acid temporarily softens and long-term can slowly erode your teeth.
Just like acid forms pockets in limestone rock (e.g. southern France and lots of other places in Europe)—it can erode pockets out of the surface of your teeth. I speak from sad personal experience (acid not from sport drinks).
. (can try web searches on like “acid erosion teeth”.)
. (hint: lots of fruit juices are significantly acidic.)
Another source of acid in the mouth is normally occurring bacteria that digest sugars (maybe they digest other carbohydrates too, but sugars seem to be what they like best). The body’s normal defense against this is lots of saliva production to dilute the acid (and help swallow the sugar). For sugar in a sport drink, I guess the drink itself would help dilute the resulting acid—(if it were a brand which is not already significantly acidic).
So currently I’m in a “reform” phase where I drink on tours either plain water or decaf coffee with milk.
Caffeine:
Sometimes I used to drink full-caffeine coffee during a tour, but since then I read that it doesn’t help with athletic performances longer than an hour - (though it is well-known to provide a temporary boost in aerobic performances much shorter than an hour)
EPO:
It’s a normal substance in our body. We would die after some period of time without it.
Frequent skiing at altitudes typical for the European Alps stimulates production of additional EPO. So if you think EPO is in itself an evil substance, then consider moving to Norway so you can ski at lower altitude.
Likewise using altitude-simulation tents/rooms or other means of breathing reduced-oxygen air stimulates additional EPO. It’s a (currently?) sport-legal method of manipulating EPO that avoids injections - (though I assume it’s less effective than injections).
I would guess that the percentage of top ski-mountaineering racers using altitude-simulation tents is significantly larger than zero.
The basic problem with EPO is that it works: it does its job of increasing the concentration of red blood cells. Result A: more oxygen to the muscles.
Result B: increased risk of unintended clotting.
Small increase in red blood cell count ==> Small increase in incidence of embolisms + strokes
Large increase in red blood cell count ==> Large increase in incidence of embolisms + strokes
So if you spend lots of time skiing in the Alps, you’re slightly increasing the risk of having an embolism or stroke (other things being equal, which they usually aren’t).
Myself, I’ll keep doing it.
Ken