Administration of Caffeine in Alternate Forms

Abstract

There has been recent interest in the ergogenic effects of caffeine delivered in low doses (~ 200 mg or ~ 3 mg/kg body mass) and administered in forms other than capsules, coffee and sports drinks, including chewing gum, bars, gels, mouth rinses, energy drinks and aerosols. Caffeinated chewing gum is absorbed quicker through the buccal mucosa compared with capsule delivery and absorption in the gut, although total caffeine absorption over time is not different. Rapid absorption may be important in many sporting situations. Caffeinated chewing gum improved endurance cycling performance, and there is limited evidence that repeated sprint cycling and power production may also be improved. Mouth rinsing with caffeine may stimulate nerves with direct links to the brain, in addition to caffeine absorption in the mouth. However, caffeine mouth rinsing has not been shown to have significant effects on cognitive performance. Delivering caffeine with mouth rinsing improved short-duration, high-intensity, repeated sprinting in normal and depleted glycogen states, while the majority of the literature indicates no ergogenic effect on aerobic exercise performance, and resistance exercise has not been adequately studied. Studies with caffeinated energy drinks have generally not examined the individual effects of caffeine on performance, making conclusions about this form of caffeine delivery impossible. Caffeinated aerosol mouth and nasal sprays may stimulate nerves with direct brain connections and enter the blood via mucosal and pulmonary absorption, although little support exists for caffeine delivered in this manner. Overall, more research is needed examining alternate forms of caffeine delivery including direct measures of brain activation and entry of caffeine into the blood, as well as more studies examining trained athletes and female subjects.

Fig. 1

Mean caffeine plasma concentration profiles following a 50-, 100- or 200-mg dose of caffeine, delivered as either a capsule or gum formulation to healthy male volunteers (12 subjects in each of the seven treatment groups) Reproduced from Kamimori et al. [24], with permission

Fig. 2

Mean caffeine plasma concentration profiles following a 200-mg dose of caffeine as a capsule or gum formulation to healthy male volunteers (12 subjects in each of the two treatment group). Inset shows plasma concentration profiles of the 200-mg dose delivered in capsule or gum formulation up to 90 min after caffeine administration Reproduced from Kamimori et al. [24], with permission

Fig. 3

Mean power output combined for males and females during cycling time trial. Data are presented as mean ± standard deviation. BJ beetroot juice, CAFF caffeine, CAFF + BJ caffeine with beetroot juice, CONT placebo. *Different from CONT and BJ (p < 0.01) Reproduced from Lane et al. [29], with permission

Fig. 4

Peak and average power profiles and ratings of perceived pain for five, 6-s sprints separated by 24 s active rest in control (CON), glycogen depletion and placebo (PLA), and glycogen depletion and caffeine (CAF) conditions. a Peak power; b mean power; and c perceived pain. Data are presented as mean ± standard deviation. ^§CON significantly greater than PLA (p < 0.05); # CON significantly greater than CAF (p < 0.05); ^#CAF significantly greater than PLA (p < 0.05); ^¥CON significantly less than PLA (p < 0.05); ^&CAF significantly less than PLA (p < 0.05) Reproduced from Kizzi et al. [47], with permission