Low intensity extended duration effort is aerobic. Your anaerobic capacity weighs in when intense effort involving strength, speed and power is involved. A study published in the International SportMed Journal gives you some idea of the role caffeine can play in this type of training.
Researchers had 8 male subjects in their mid-20s engage in 4 constant load bouts of cycling to exhaustion. The first session was performed at 80% of peak power output with the next session increased to 90%, followed by 100% and finally 110% of peak powder output.
Subjects received either 6 mg of caffeine per kg of body weight (462 mg for a 170 pound guy) or a placebo. Time to exhaustion improved 12% to 17% with caffeine, and anaerobic work capacity was an average of 23% better. That's how you outlast and push past the competition.