Those without lung disease should be able to adapt to an altitude of 7200 ft pretty much immediately. I think the value of acclimatization doesn't hit until around 9-10,000 ft or so, where it will take time for the body to make physiological adjustments. Coming from sea-level would actually be an advantage in a sport like football because it is based on speed and the recovery at sea-level is faster. Training at low altitude long-term allows an athlete to train harder and faster and develop more fast-twitch muscle. However, since we are working out at this tough altitude all the time we should have better fitness. Football is not an endurance sport per se but the game is a couple hours long and recovery is important. Even though athletes from different elevations would be equal at 7000ft we SHOULD have the conditioning advantage, they will have the speed advantage. I would think the mental influence would be significant too. Both athletes suffer equally but it feels much scarier to the low-lander not being able to catch his breath.
Also, taking on oxygen during a game is totally cheating in my book. I never understood why they allowed that. The increase percentage of oxygen concentration from the canned air definitely makes up for the lack of oxygen due to pressure (correctly explained above). This would enable an athlete to recover faster on the sideline and also decrease muscular fatigue over the course of the game. Now maybe those guys in the Tour are shooting up with EPO in their hotel rooms but you sure as hell wouldn't see them pull up to the team car in the middle of the race and huff down some pure O2 on live TV- ridiculous!
Also, taking on oxygen during a game is totally cheating in my book. I never understood why they allowed that. The increase percentage of oxygen concentration from the canned air definitely makes up for the lack of oxygen due to pressure (correctly explained above). This would enable an athlete to recover faster on the sideline and also decrease muscular fatigue over the course of the game. Now maybe those guys in the Tour are shooting up with EPO in their hotel rooms but you sure as hell wouldn't see them pull up to the team car in the middle of the race and huff down some pure O2 on live TV- ridiculous!