Smoking increases hemoglobin and hematocrit.

Btw I have smoked 2 cigarettes in my life, to see what the hype was about. Disgusting!

Although, I do like the aroma of some pipe tobacco.

As you said, due to the hypoxic conditions created by smoking. Same concept as those living at altitude.

Malmo can likely verify, but I have had in-depth discussions with many top Americans from the 70s and 80s and nearly all of them had stories about very good UK and Euro pros lighting up a celebratory cigarette once off of the track.

Wow, could this cure my anemia?

(reliable) source? -5/10

Prerace meal is a pound of spinach and a pack of cigs. The popeye way

I didn’t take the time to see if there was a newish study from the Cleveland Clinic. If there is a study from the Cleveland Clinic that shows this, there aren’t going to be that many sources that are more reliable.

It is an adaptive mechanism and not new. This has been known for a long time. The negatives, though, far outweigh any positives. Did the study show something new?

As an aside, a friend of mine used to tuck a cigarette into his sock when he was warming up for XC meets. When he was away from the coach and in the woods he would smoke it. He was a pretty decent runner and was in the 15:30 range for a 5k and was top 10 in Ohio at the state meet one year. He made sure the guys from the other schools could smell the smoke on him before the meet and I think he did it to sort of play with their heads. In the off season he was a regular smoker of cigarettes and weed. I would like to see how good he would have been if he didn’t smoke. He had two brothers that ran at Ivy schools and were really good yet he had more natural ability so he probably would have been good.

you wouldn't get a hypoxic environment outside of COPD which would not lead to any PRs

Not like PEDs do.
Smokers impacts the blood in two negative ways; causes chronic low grade carbon monoxide poisoning, and damages the lungs in about 20% of smokers. Carbon monoxide binds hemoglobin with >200 times the affinity of oxygen so smoking decreases your ability to absorb oxygen from the lungs and carry to the tissues via hemoglobin. The body compensates by raising your hemoglobin. So you’ll have higher hemoglobin but it’s less effective at doing it’s job.
A high hemoglobin in a smoker (>18) is one indication for supplemental home oxygen. All those patients with COPD carrying oxygen tanks around with them… are NOT ‘benefiting from smoking like PEDs’.

Bill Rodgers was a smoker.

There's a quote somewhere about Chris Chataway (who held the world record in the 5000m for about 10 days in 1954) not being able to finish a 5 mile cross country race unless someone was on the sidelines at the 3 mile mark with a lit cigarette. Chataway would take the cigarette, puff a few times, and then he could complete the race.

I've heard of some European cyclist using snus(smokeless tobacco). Obviously there's the cancer risk from using smokeless tobacco and dehydration from spitting. But nicotine in isolation have shown some benefits. Personally, I started dipping when I was in the military, mostly because I was bored and there was too much stand by and wait, so it was just something to do. And in the field it would work similar to caffeine as far as to keep me on alert and focus. Especially on days you're up for 24 hours or longer, operating on MREs. I never notice negative effects as far as running goes.