The Metabolic and Performance Effects of Caffeine Compared to Coffee during Endurance Exercise

Abstract

There is consistent evidence supporting the ergogenic effects of caffeine for endurance based exercise. However, whether caffeine ingested through coffee has the same effects is still subject to debate. The primary aim of the study was to investigate the performance enhancing effects of caffeine and coffee using a time trial performance test, while also investigating the metabolic effects of caffeine and coffee. In a single-blind, crossover, randomised counter-balanced study design, eight trained male cyclists/triathletes (Mean±SD: Age 41±7y, Height 1.80±0.04 m, Weight 78.9±4.1 kg, VO2 max 58±3 ml•kg−1•min−1) completed 30 min of steady-state (SS) cycling at approximately 55% VO2max followed by a 45 min energy based target time trial (TT). One hour prior to exercise each athlete consumed drinks consisting of caffeine (5 mg CAF/kg BW), instant coffee (5 mg CAF/kg BW), instant decaffeinated coffee or placebo. The set workloads produced similar relative exercise intensities during the SS for all drinks, with no observed difference in carbohydrate or fat oxidation. Performance times during the TT were significantly faster (∼5.0%) for both caffeine and coffee when compared to placebo and decaf (38.35±1.53, 38.27±1.80, 40.23±1.98, 40.31±1.22 min respectively, p<0.05). The significantly faster performance times were similar for both caffeine and coffee. Average power for caffeine and coffee during the TT was significantly greater when compared to placebo and decaf (294±21 W, 291±22 W, 277±14 W, 276±23 W respectively, p<0.05). No significant differences were observed between placebo and decaf during the TT. The present study illustrates that both caffeine (5 mg/kg/BW) and coffee (5 mg/kg/BW) consumed 1 h prior to exercise can improve endurance exercise performance.

Quantitative estimation of the caffeine content in some energy drinks on the Ghanaian market

“…People with heart problems are advised against taking caffeine because it increases heart rate. It can also cause heart burns because it increases gastric acid production (Hodgson et al, 2013). Taken in high amounts, caffeine can also cause insomnia, tremors, nervousness and headaches (Smith, 2002).…”

Effects of high dose coffee intake on aerobic power in dragon female athletes

“…Numerous studies have shown that caffeine can act as an ergo-genic aid, in long-term exercise [5][6][7][8][9]. Caffeine's primary ergo-genic mode of action is on the CNS [10].…”

“…Most research, have investigated the effect of low or moderate doses of caffeine consumption on performance, perceptual responses and Neuromuscular factors prior to endurance exercise [7][8][9]13,14]. Nevertheless, there are a few studies that considered the effect of high doses of caffeine on endurance exercise [15,16].…”

“…In addition, a few studies indicated the effect of pre exercise coffee on endurance exercises [7,8,16,[18][19][20] and they demonstrated difference results. Hodgson et al (2013) utilized coffee and caffeine in their Research and shown that both of caffeine and coffee (5mg/kg) consumption one hour prior to exercise can improve endurance exercise performance [8].…”

Mécanismes de l’effet diurétique de la caféine

“…Ces effets pourraient expliquer la symptomatologie de reflux gastro oesophagien décrite par certains consommateurs de café [9]. Enfin, la caféine est dotée d'effets métaboliques sur la glycogénolyse et la lipolyse au niveau des muscles squelettiques, des reins et du foie, avec pour résultat global, une amélioration des performances physiques [10]. Outre les effets systémiques de la caféine que nous avons brièvement mentionnés, la caféine exerce un effet diurétique significatif lors d'une ingestion de 300 mg, soit 4 à 5 tasses de café [11,12].…”