Winnie is good but your BP and cholesterol will skyrocket.
I am exclusively an endurance athlete, but I do gear to keep from shrinking down to a stick. Some bros have the genes to get huge, some bros (like me) have the genes to climb huge mountains...
I would actually tell you to seriously consider a bulking cycle. You will have a hell of a lot more endurance with a larger muscle pack on your frame. Not huge, just an athletic build, which is what I have...I could not have had it without a bulking cycle....
After that, I would also reccomend Primobolan. Not too popular these days, but boy, it fights catabolism MUCH better than winnie. It is exceptionally gentle on your system. In fact, it is used to keep aids patients alive and promote tissue retention and regeneration in burn victims.
The downside is that it is expensive. Winnie will help you get your red blood cells up, but the effects are not long lasting, and it will harden your arteries.
Most bros here aren't like us, they're dedicated bodybuilders. Winstrol is the drug of choice for them. But for you, needing to survive long hard training sessions for months on end without breaking down, well--primobolan is your answer.
A lot of bros will bridge their cycles with Primo so they don't lose any gains--it is very mild. Some people have chosen to stay on primo for years on end, just doing 100-200mgs a week.
Just as we aren't able to put on huge slabs of muscle like genetically gifted bodybuilders--they can't make and maintain the same cardio gais we can. That is why they NEED winstrol--to increase their red blood cell count. The cardio that they do, even pre contest is nothing compared to what we do. Last year I spent 18 hours on my feet above 10,000 feet climbing a coastal volcano with an extra 35 lbs of shit on my body...Endurance atheletes are a different breed. Powerlifters don't run marathons. Triathletes don't win strongman comps.
So from one endurance athlete to another: Bulk up a little, just a little, and stay conditioned durign the bulking cycle...and when you go into training for Tri-A, I have one word for you: Primobolan!
Peace
ZB