The only steroid that would really benefit an athlete would be EQ because it increases red blood cell count and doesnt cause a whole lot of water retention. Unless you are on TRT and are using the test to keep your test levels in the normal range, I wouldn't add testosterone into your cycle lay out. It'll cause water retention and make you slower.
I would forgo steroids altogether and use SARMS instead. Even steroids like EQ will probably hurt your performance, not improve it.
Steroids like EQ also open up a whole bag of worms of other issues because they are suppressive of natural testosterone production. After using EQ, you would need to run a full PCT which gets very expensive.
SARMS are going to be your best option as an athlete. Steroids will increase strength, but they will also cause a lot of water retention and negatively impact endurance. Your sports performance will actually probably be worse on the steroids then before you started the cycle. You might actually be slower when using the steroids because of the amount of body weight and water retention you gain on the cycle.
SARMS on the other hand will directly increase endurance, fat loss and recovery. They aren't as strong as steroids in terms of strength and muscle gains but you get all the good, with none of the side effects. They don't cause water retention, are only minimally suppressive of natural testosterone production and aren't liver toxic. You will still increase strength on SARMS, just not to the same extent that you would on steroids.
The SARMS triple stack (S4 + ostarine + cardarine) would be a great first cycle to run:
http://www.evolutionary.org/the-SARMS-triple-stack-protocol
Cardarine will directly increase fat loss and endurance
Ostarine will increase recovery
S4 will increase strength and lean mass
You get the best of everything with the triple stack
After the triple stack, run a mini PCT. 4 weeks of the following:
HCGenerate ES at 5 capsules/day
SARMS are minimally suppressive, there is no risk of aromatization (therefore no estrogen related side effects) and legal to use. You can get everything you need off sarms1.com, n2bm.com and ag-guys.com