As evidenced by the lack of believer response to the question of athletes praying for help from God, I propose that believers do not actually "believe" in any sense of the word that we normally accept. Belief in the supernatural claims of God or the paranormal, for them, is not really ever extrapolated into the world of physical reality, beyond the level of dream-like hypothesis where the contours of what is realy change whimsically.
The question of an athlete's use of prayer is not a frivolous or specious ambush on believer's claims, but rather a question that goes to the heart of whether or not religious belief can truly be called a "belief" at all, or whether it is simply a "what-if" concept that grows to the extent that it overwhelms rational judgement.
If one truly believes that God intervenes, as apparently those athletes who give credit to Him after winning an event do, then one must face the ethical conundrum of whether an athlete who prays for success is cheating in the same manner as one who takes drugs.
If such a notion sounds silly, it is only because "belief" in the supernaturalness of God seems to enjoy a special status as distinct from other beliefs -- a kind of exemption from actuality which allows one to hold the belief but never act upon its implications.
This exemption is NOT, however, an expression of faith, and faith is not a rationale for the exemption. Faith is simply what allows the belief to be held in the first place -- but once held, the belief is subject to logical consequences that believers consistently avoid.
A small number of believers do display an actual, non-exempted form of belief -- but they are almost always spurned by mainstream (belief-exempted) religion, not to mention the secular world, as being cultist whackos (and they are!). Believers who, for example, refuse medical treatment in deference to God's will, in fact exhibit belief which extends logically from faith into the real world. If one truly "believes" that God works miracles, rather than pretend-hypothesizing such, then why not leave it up to God for His will to be done?
If people who skydive believed in their parachutes in the same way that Christians "believe" in the supernaturalness of God, no sane person would ever skydive.