Caffeine and Exercise Performance - Caffeine: Chemistry, Analysis, Function and Effects - page 324

Table 17.4 Summary of areas that require investigation of the ergogenic

effects of caffeine.

1. To investigate the effect of fed state on ergogenic effects of caffeine.
2. To investigate the effect of training status on ergogenic effects of caffeine.
3. To investigate ergogenic effects of caffeine in persons of various gender, age, and
body composition.
4. To investigate ergogenic effects of caffeine during sprint- and power-based
exercise in sprint-trained athletes.
5. To investigate efficacy of other items containing caffeine, such as energy drinks,
chewing gum, etc., on exercise performance.
6. To investigate if chronic caffeine intake can promote exercise adherence and
tolerance to exercise in sedentary populations.
7. To investigate efficacy of acute or repeated caffeine intake on job performance in
firefighters, soldiers, and other personnel undergoing sustained operations.
8. To investigate efficacy of acute caffeine intake for resistance training
performance.
9. To investigate effects of various length of withdrawal on ergogenic effects of
caffeine.
10. To investigate effects of caffeine combined with exercise on weight loss in
overweight and obese individuals.
11. To compare ergogenic effects of caffeine across men and women of similar
training status.
12. To confirm if adenosine antagonism is the primary mechanism explaining
ergogenic effects of caffeine during intense exercise.

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power with caffeine. In strength-trained men completing supersets of leg press
and bench press, no effect of caffeine on performance was revealed (Jacobs et al
2003). Similarly, there was no effect of caffeine on 1-RM bench press and leg
press (Astorino et al 2008) or bench press and lat pull down in strength-trained
men (Williams et al 2008). Nevertheless, Beck et al (2006) reported a significant
increase in 1-RM bench press in men ingesting a caffeine-containing (201 mg)
supplement, although the magnitude of this increase was small (+ 2.0%). In elite
male athletes, bench press but not leg press performance was augmented with
caffeine (Woolf et al 2008). However, these data oppose findings (Astorino et al
2011) showing improved leg press performance in strength-trained men, yet no
change in bench press, shoulder press, or lat row performance. Compared to
placebo, Warren et al (2010) reported 4 and 14% improvements in muscle
strength and endurance with caffeine, with the ergogenic effect typically

observed in the knee extensors versus other muscle groups.
Overall, caffeine seems to augment muscle strength and endurance only
under specific conditions. The majority of data show minimal alterations in 1-
RM strength, repetitions completed at a given load, peak torque, or power.
Most studies reporting significant increases in performance are characterized
by higher doses (5-7 mg kg 21 ), use of open end point tests, and caffeine
combined with other constituents that may alter performance. Despite its
purported anti-fatigue properties, caffeine may not be ergogenic during

resistance training, especially when fixed end point tests are used.