Effects of caffeine chewing gum supplementation on exercise performance: A systematic review and meta-analysis.

The aim of this systematic review with meta-analysis was to determine the effect of caffeine gum (Caff-gum) on exercise performance-related outcomes. Several databases were searched for studies assessing the effect of Caff-gum in placebo-controlled protocols involving healthy adults. Random-effects meta-analyses using standardized mean differences (SMD) were performed to determine the effect of Caff-gum on exercise outcomes with several sub-analyses (training status, exercise type, timing and dose) for potential modifying factors. 14 studies were included, totalling 200 participants. There was a significant overall effect of Caff-gum compared to placebo (SMD = 0.21, 95%CI: 0.10-0.32; p = 0.001). Subgroup analysis showed improved performance for trained (SMD = 0.23, 95%CI: 0.08-0.37; p = 0.004), but not for untrained (SMD = 0.14, 95%CI: -0.02-0.29; p = 0.07) individuals. Caff-gum improved both endurance (SMD = 0.27, 95%CI: 0.12-0.42; p = 0.002) and strength/power (SMD = 0.20, 95%CI: 0.03-0.37; p = 0.03) performance outcomes. Caff-gum was ergogenic when consumed within 15 min prior to initiating exercise (SMD = 0.27, 95%CI: 0.07-0.4; p = 0.01), but not when provided >15 min prior (SMD = -0.48, 95%CI = -1.7-0.82; p = 0.25). There was no significant effect of Caff-gum with doses <3 mg/kg body mass (BM) (SMD = 0.20, 95%CI: -0.03-0.43; p = 0.07), but there was a significant effect when the dose was ≥3 mg/kg BM (SMD = 0.22, 95%CI: 0.07-0.37; p = 0.01). Caff-gum supplementation may be an effective ergogenic strategy for trained athletes involved in both endurance and strength/power exercise, using a recommended dose of ≥3 mg/kg BM consumed within 15 min of initiating exercise.HighlightsThis study determined the effect of Caff-gum on exercise performance, using a systematic review and meta-analysis. Fourteen studies, totalling 200 participants performing a variety of endurance and strength/power exercise tests were included. The relative Caff-gum dose ranged from 1.27-4.26 mg/kg BM and timing ranged from 120 min prior to exercise up to intra-test application.Caff-gum was shown to be an effective ergogenic aid for trained individuals involved in both endurance and strength/power exercise.Supplement dose and timing modified the efficacy of Caff-gum. Supplementation with Caff-gum was effective when provided in doses ≥3 mg/kg BM and within 15 min prior to initiating exercise.Trained endurance or strength/power athletes seeking to benefit from caffeine in the form of chewing gum should supplement within 15 min prior to initiating an exercise task, in doses ≥3 mg/kg BM.

Effect of butanolic fraction of Desmodium adscendens on the anococcygeus of the rat.

The chemical composition of plants can vary according to factors such as soil and time of collection. Desmodium adscendens (Sw.) D.C. var. adscendens (Papillionaceae) is a plant employed in the treatment of asthma in Ghana, Africa. Studies have shown that butanolic extract inhibits contraction of the ileum and trachea in guinea pigs. In Mato Grosso, this plant is used only in the treatment of ovarian inflammation. The objective of this work was to verify if the plant found in Mato Grosso also relaxes smooth muscle and to understand better its action. The cumulative application of the butanolic fraction relaxed the contraction maintained in the isolated anococcygeus of a rat, induced by high potassium, but not that induced by phenylephrine. Relaxation was not altered by methylene blue. The butanolic fraction reduced in a concentration-dependent way the maximum response of concentration-response curve to calcium in the anococcygeus muscle. The results suggest that the butanolic fraction acts, at least partly, through the blockade of voltage-sensitive Ca+2 channels.

Effect of butanolic fraction of Desmodium adscendens on the anococcygeus of the rat

The chemical composition of plants can vary according to factors such as soil and time of collection. Desmodium adscendens (Sw.) D.C. var. adscendens (Papillionaceae) is a plant employed in the treatment of asthma in Ghana, Africa. Studies have shown that butanolic extract inhibits contraction of the ileum and trachea in guinea pigs. In Mato Grosso, this plant is used only in the treatment of ovarian inflammation.The objective of this work was to verify if the plant found in Mato Grosso also relaxes smooth muscle and to understand better its action.The cumulative application of the butanolic fraction relaxed the contraction maintained in the isolated anococcygeus of a rat, induced by high potassium, but not that induced by phenylephrine. Relaxation was not altered by methylene blue. The butanolic fraction reduced in a concentration-dependent way the maximum response of concentration-response curve to calcium in the anococcygeus muscle. The results suggest that the butanolic fraction acts, at least partly, through the blockade of voltage-sensitive Ca+2 channels