Effects Of Caffeine On High-Intensity Performance
Nelson Marlborough Institute of Technology
Literature Review
Caffeine & High-Intensity Power Out-Put
Author:
10/16/2013
Diploma in Applied Fitness
Exercise Science
Table of Contents
What are the effects of caffeine on power output during high-intensity performance?
1 Introduction
The effect caffeine (CAFF) elicits on sustained endurance performance is well founded (Costill, Dalsky, & Fink, 1978; Graham, & Spriet, 1991; Trice, & Haymes, 1995; Erickson, Schwarzkoff, & McKenzie, 1987). However, comparatively less research has been conducted on the ergogenic potential of CAFF on anaerobic performance (Wiles, Coleman, Tegerdine, & Swaine, 2006; Crowe, Leicht, & Spinks, 2006). Furthermore, several studies that have been carried out on CAFF ingestion and the response to high-intensity exercise have …show more content…
conflicting results (Greer, Morales, & Coles, 2006; Crowe et al, 2006; Doherty, Smith, Hughes, & Davison, 2004). CAFF is one of the most widely consumed drugs in the world (Greer et al, 2006) it is readily available in many forms including, over the counter medications and foods such as coffee, tea and chocolate. CAFF is known to cause side effects comparable to anxiety, sleeplessness and restlessness which could possibly be detrimental to an athlete’s performance.
Therefore this review is to alert athletes, coaches and trainers to the scientific evidence surrounding caffeine ingestion and its effects on peak power output during high-intensity exercise. This is important for anyone involved in high-intensity training/coaching in that it can help determine whether or not there are benefits of CAFF supplementation. Moreover, this will help gain an understating of optimal CAFF dosage.
Research entailing the effects of CAFF on power output was acquired via searching the Sports Discus database through Nelson Marlborough Institute of Technology library. Resourcing from journals such as; Journal of Sports Science; International Journal of Sport Nutrition and Exercise Metabolism; Applied Physiology, Nutrition, and Metabolism
Key words; High-intensity, effects, anaerobic, caffeine, performance, peak power, physiological
2 Table of Literature
Summary of literature pertaining to caffeine ingestion and power output
Study (year)
No. and sex
Habitual use
Dosage
Population
Workload
Findings (power output)
Crowe et al,
2006
12 M
+
5 F
3 M + 1 F, light – mod
80 - 200 mg/d
6 mg/kg non- specifically trained, regular team sport players
2 x 60 sec max cycle
peak power slower time to peak power
Greer et al,
2006
18 M
0 - habitual users 5 mg/kg
non-specifically trained, recreationally active 30-s Wingate
peak power
Astorino et al,
2011
15 M light – heavy
120 – 600 mg/d
2 mg/kg
5 mg/kg non-specifically trained, recreationally active
2 x max cycle bouts of 40 revs
peak power with
5 mg/kg caffeine
Doherty et al,
2004
11 M light – mod
95 – 275 mg/d
5 mg/kg specifically trained cyclists
1 min all out cycle
mean power
Wiles et al,
2006
8 M
N/S
5 mg/kg specifically trained cyclists
1 km all out max cycle sprint
peak power
mean power
Kilding et al,
2012
10 M
N/S
3 mg/kg specifically trained cyclists
3 km max cycle
Peak power
mean power
max = maximal; min = minutes; M = male subjects; F = female subjects; N/S = not specified;
= indicates no difference; = indicates increase; reps = repetitions
3 5 Paper Summaries
3.1 Physiological and cognitive responses to caffeine during repeated, high-intensity exercise (Crowe et al, 2006)
Young healthy male and female subjects were placed in groups of control, CAFF (6mg/kg) or placebo and commenced a 2 x 60 s maximal cycle test, peak power was recorded. This resulted in no significant effect of CAFF ingestion on peak power however did produce a notably slower time to peak power in the second bout. According to this study, ingestion of CAFF (6mg/kg) up to 90 minutes prior to an all out maximal 60 second cycle will have no significant effect on the ability to produce peak power but may result in slower time to peak power. (98 words)
3.2 Wingate performance and surface EMG frequency variables are not affected by caffeine ingestion (Greer et al, 2006)
Eighteen recreationally active young male subjects consumed capsules containing either CAFF (5mg/kg) or placebo one hour prior to performing a Wingate test, power output was recorded every 5 seconds of the 30 seconds. An increase of peak power in 12 subjects and mean power in 11 subjects was recorded although was not significant. The data from the present study suggests that CAFF ingestion (5mg/kg) 1 hour prior to a 30 second all-out Wingate test will not have an ergogenic effect on peak power output. (84 words)
3.3 Effect of caffeine intake on pain perception during high-intensity exercise (Astorino et al, 2011)
Regularly active men (15) whom consume > 100mg/d of CAFF were tested for peak power out-put during 2 x all-out bouts on a cycle ergometer consisting of 40 repetitions of knee flexion and extension. One hour prior to the test subjects were given either CAFF (5mg/kg), (2mg/kg) or placebo treatment. 5mg/kg of CAFF resulted in a significant increase of power during knee flexion and extension compared with placebo. Based on the evidence found in this study it would be beneficial to ingest 5mg/kg of CAFF one hour prior to short bursts of high-intensity cycling if the desired outcome is increased peak power output. (103 words)
3.4 Caffeine lowers perceptual response and increases power output during high-intensity cycling (Doherty et al, 2004)
Trained male cyclists (11) with season best 40-km performance ingested either treatment of CAFF (5mg/kg) or placebo and were tested one hour later for power output during a 1 minute all out maximal cycle conducted on the participants own bikes. Peak power and mean power output increased significantly in the CAFF treatment during the high intensity performance compared to the placebo treatment. Evident in the present study is the ingestion of CAFF one hour prior to an all out maximal cycle of sixty seconds has a significant increased effect on peak and mean power out-put. (95 words)
3.5 The effects of caffeine ingestion on performance time, speed and power during a laboratory-based 1km cycling time trial (Wiles et al, 2006)
Competitive male road race cyclists (8) whom are experienced and habitual to high-intensity training took part in the test designed to closely mimic track racing conditions. Receiving treatment of CAFF (5mg/kg) or placebo one hour prior to testing which consisted of an all-out maximal sprint for 1 km with power output being recorded. Increases were seen in peak power, mean power and performance time when express relative to the placebo treatment. The ingestion of CAFF (5mg/kg) one hour prior to a 1 km cycling time trial is suggested for an increase in overall performance. (94 words)
4 Review Summary and Practical Application
The majority of the case studies being reviewed have auspicious results regarding the effects of CAFF on peak power output during short bouts of high-intensity cycling. Whiles et al, 2006; Doherty et al, 2004; Astorino et al, 2011 similarly finding the ingestion of 5mg/kg of CAFF one hour prior to short bouts of high- intensity cycling resulted in an increase of peak power out-put. Subjects from Whiles et al, 2006 & Doherty et al, 2004 were specifically trained athletes, whom consume light-moderate levels of CAFF regularly or not specified. Whereas Astorino et al, 2011 tested non-specifically trained subjects who also consumed similar or higher levels of CAFF on a regular basis, this variation suggests that peak power out-put will increase for specifically trained or non-specifically trained populations. However more research is required.
In contrast to these results Crowe et al, 2006 & Greer et al, 2006 found no change in peak power out-put after the ingestion of CAFF during bouts of high-intensity cycling when compared to placebo treatment. Similar to Astorino et al, 2011 these studies both tested non-specifically trained subjects and used a CAFF dosage the same as, or very close to that of Whiles et al, 2006; Doherty et al, 2006 & Astorino et al, 2011. Also of importance Greer et al, 2006 tested subjects that were naive to CAFF and still found contradicting results. These equivocal data suggest that there is variation in subjects’ ability to improve performance with CAFF, which is possibly mediated by discrepancies in CAFF metabolism (Gonzalez, Kalow & Tang, 1992).
As a matter of fact Crowe et al, 2006 found CAFF may have been detrimental to performance resulting in a much slower time to reach peak power in the second exercise bout. However the exercise protocol differs between the studies and therefore it is possible that the subjects could have paced their efforts during the second exercise bout despite being instructed to do otherwise.
It is tempting to suggest that the ingestion of CAFF (5mg/kg) one hour prior to high-intensity exercise will increase the ability to produce peak power however more research is needed to further back up current findings. Furthermore, the studies being reviewed have their limitations. First, the findings can only be applied to power production via lower body exercise characterized by contractions of the knee flexors and extensors. The same findings cannot be said for upper body resistance or total body sports. Second, out of the 79 participants across the studies all of them were of younger generation and only 5 were female subjects therefore more research across a variety of populations is required. Finally it’s clear that the majority of power increases came from specifically trained subjects it seems this could have an advantage regarding CAFF effect on power production however more research on this subject is vital.
(Costill, Dalsky, & Fink, 1978) (Graham & Sprite, 1991) (Trice & Haymes, 1995) (Erickson, Schwarzkoff, & McKenzie, 1987) (Wiles, Coleman, Tegerdine, & Swaine, 2006) (Crowe, Leicht, & Spinks, 2006) (Greer, Morales, & Coles, 2006) (Doherty, Smith, Hughes, & R.C.R, 2004) (Gonzlaez, Kalow, & Tang, 1992) (Kilding, Overton, & Gleave, 2012)
5 Bibliography
Costill, D., Dalsky, G., & Fink, W. (1978). Effects of caffeine ingestion on metabolism and exercise performance. Medicine and science in sports and exercise, 155-158.
Crowe, M., Leicht, A., & Spinks, W.
(2006). Physiological and cognitive responses to caffeine during repeted, high-intensity exercise . International journal of sport nutrition and exercise metabolism, 528-544.
Doherty, M., Smith, P., Hughes, M., & R.C.R, D. (2004). Caffiene lowers perceptual response and increases power output during high-intensity cycling. Journal of sports science, 637-643.
Erickson, M., Schwarzkoff, R., & McKenzie, R. (1987). Effects of caffeine, fructose and glucose ingestion on muscle glycogen utilization during exercise. Medical science of sports and exercise, 579-583.
Gonzlaez, G. L., Kalow, F. J., & Tang, B. K. (1992). Bio-transformation of caffeine, paraxanthine, theobromine, and theophylline by cDNA-expressed human CYP1A2 and CYP2EA. Pharmacogenetics, 73-77.
Graham, T., & Sprite, L. (1991). Performance and metabolic responses to high caffeine dose during prolonged ecercise. Journal of applied physiology, 2292-2298.
Greer, F., Morales, J., & Coles, M. (2006). Wingate performance and surface EMG frequency variables are not affected by caffeine ingestion. Applied physiology, nutrition, and metabolism,
597-603.
Kilding, A., Overton, C., & Gleave, J. (2012). Effects of caffeine, sodium bicarbonate, and their combined ingestion on high-intensity cycling performance. International journal of sport nutrition and exercise metabolism, 175-183.
Trice, I., & Haymes, E. (1995). Effects of caffeine ingestion on exercise in duced changes during high-intensity, intermittent exercise. International journal of sports exercise, 37-44.
Wiles, J., Coleman, D., Tegerdine, M., & Swaine, I. (2006). The effects of caffeine ingestion on performance time, speed and power during a laboratory-based 1 km cycle time-trial. Journal of sports science, 1165-1171.
Literature Review
Caffeine & High-Intensity Power Out-Put
Author:
10/16/2013
Diploma in Applied Fitness
Exercise Science
Table of Contents
What are the effects of caffeine on power output during high-intensity performance?
1 Introduction
The effect caffeine (CAFF) elicits on sustained endurance performance is well founded (Costill, Dalsky, & Fink, 1978; Graham, & Spriet, 1991; Trice, & Haymes, 1995; Erickson, Schwarzkoff, & McKenzie, 1987). However, comparatively less research has been conducted on the ergogenic potential of CAFF on anaerobic performance (Wiles, Coleman, Tegerdine, & Swaine, 2006; Crowe, Leicht, & Spinks, 2006). Furthermore, several studies that have been carried out on CAFF ingestion and the response to high-intensity exercise have …show more content…
conflicting results (Greer, Morales, & Coles, 2006; Crowe et al, 2006; Doherty, Smith, Hughes, & Davison, 2004). CAFF is one of the most widely consumed drugs in the world (Greer et al, 2006) it is readily available in many forms including, over the counter medications and foods such as coffee, tea and chocolate. CAFF is known to cause side effects comparable to anxiety, sleeplessness and restlessness which could possibly be detrimental to an athlete’s performance.
Therefore this review is to alert athletes, coaches and trainers to the scientific evidence surrounding caffeine ingestion and its effects on peak power output during high-intensity exercise. This is important for anyone involved in high-intensity training/coaching in that it can help determine whether or not there are benefits of CAFF supplementation. Moreover, this will help gain an understating of optimal CAFF dosage.
Research entailing the effects of CAFF on power output was acquired via searching the Sports Discus database through Nelson Marlborough Institute of Technology library. Resourcing from journals such as; Journal of Sports Science; International Journal of Sport Nutrition and Exercise Metabolism; Applied Physiology, Nutrition, and Metabolism
Key words; High-intensity, effects, anaerobic, caffeine, performance, peak power, physiological
2 Table of Literature
Summary of literature pertaining to caffeine ingestion and power output
Study (year)
No. and sex
Habitual use
Dosage
Population
Workload
Findings (power output)
Crowe et al,
2006
12 M
+
5 F
3 M + 1 F, light – mod
80 - 200 mg/d
6 mg/kg non- specifically trained, regular team sport players
2 x 60 sec max cycle
peak power slower time to peak power
Greer et al,
2006
18 M
0 - habitual users 5 mg/kg
non-specifically trained, recreationally active 30-s Wingate
peak power
Astorino et al,
2011
15 M light – heavy
120 – 600 mg/d
2 mg/kg
5 mg/kg non-specifically trained, recreationally active
2 x max cycle bouts of 40 revs
peak power with
5 mg/kg caffeine
Doherty et al,
2004
11 M light – mod
95 – 275 mg/d
5 mg/kg specifically trained cyclists
1 min all out cycle
mean power
Wiles et al,
2006
8 M
N/S
5 mg/kg specifically trained cyclists
1 km all out max cycle sprint
peak power
mean power
Kilding et al,
2012
10 M
N/S
3 mg/kg specifically trained cyclists
3 km max cycle
Peak power
mean power
max = maximal; min = minutes; M = male subjects; F = female subjects; N/S = not specified;
= indicates no difference; = indicates increase; reps = repetitions
3 5 Paper Summaries
3.1 Physiological and cognitive responses to caffeine during repeated, high-intensity exercise (Crowe et al, 2006)
Young healthy male and female subjects were placed in groups of control, CAFF (6mg/kg) or placebo and commenced a 2 x 60 s maximal cycle test, peak power was recorded. This resulted in no significant effect of CAFF ingestion on peak power however did produce a notably slower time to peak power in the second bout. According to this study, ingestion of CAFF (6mg/kg) up to 90 minutes prior to an all out maximal 60 second cycle will have no significant effect on the ability to produce peak power but may result in slower time to peak power. (98 words)
3.2 Wingate performance and surface EMG frequency variables are not affected by caffeine ingestion (Greer et al, 2006)
Eighteen recreationally active young male subjects consumed capsules containing either CAFF (5mg/kg) or placebo one hour prior to performing a Wingate test, power output was recorded every 5 seconds of the 30 seconds. An increase of peak power in 12 subjects and mean power in 11 subjects was recorded although was not significant. The data from the present study suggests that CAFF ingestion (5mg/kg) 1 hour prior to a 30 second all-out Wingate test will not have an ergogenic effect on peak power output. (84 words)
3.3 Effect of caffeine intake on pain perception during high-intensity exercise (Astorino et al, 2011)
Regularly active men (15) whom consume > 100mg/d of CAFF were tested for peak power out-put during 2 x all-out bouts on a cycle ergometer consisting of 40 repetitions of knee flexion and extension. One hour prior to the test subjects were given either CAFF (5mg/kg), (2mg/kg) or placebo treatment. 5mg/kg of CAFF resulted in a significant increase of power during knee flexion and extension compared with placebo. Based on the evidence found in this study it would be beneficial to ingest 5mg/kg of CAFF one hour prior to short bursts of high-intensity cycling if the desired outcome is increased peak power output. (103 words)
3.4 Caffeine lowers perceptual response and increases power output during high-intensity cycling (Doherty et al, 2004)
Trained male cyclists (11) with season best 40-km performance ingested either treatment of CAFF (5mg/kg) or placebo and were tested one hour later for power output during a 1 minute all out maximal cycle conducted on the participants own bikes. Peak power and mean power output increased significantly in the CAFF treatment during the high intensity performance compared to the placebo treatment. Evident in the present study is the ingestion of CAFF one hour prior to an all out maximal cycle of sixty seconds has a significant increased effect on peak and mean power out-put. (95 words)
3.5 The effects of caffeine ingestion on performance time, speed and power during a laboratory-based 1km cycling time trial (Wiles et al, 2006)
Competitive male road race cyclists (8) whom are experienced and habitual to high-intensity training took part in the test designed to closely mimic track racing conditions. Receiving treatment of CAFF (5mg/kg) or placebo one hour prior to testing which consisted of an all-out maximal sprint for 1 km with power output being recorded. Increases were seen in peak power, mean power and performance time when express relative to the placebo treatment. The ingestion of CAFF (5mg/kg) one hour prior to a 1 km cycling time trial is suggested for an increase in overall performance. (94 words)
4 Review Summary and Practical Application
The majority of the case studies being reviewed have auspicious results regarding the effects of CAFF on peak power output during short bouts of high-intensity cycling. Whiles et al, 2006; Doherty et al, 2004; Astorino et al, 2011 similarly finding the ingestion of 5mg/kg of CAFF one hour prior to short bouts of high- intensity cycling resulted in an increase of peak power out-put. Subjects from Whiles et al, 2006 & Doherty et al, 2004 were specifically trained athletes, whom consume light-moderate levels of CAFF regularly or not specified. Whereas Astorino et al, 2011 tested non-specifically trained subjects who also consumed similar or higher levels of CAFF on a regular basis, this variation suggests that peak power out-put will increase for specifically trained or non-specifically trained populations. However more research is required.
In contrast to these results Crowe et al, 2006 & Greer et al, 2006 found no change in peak power out-put after the ingestion of CAFF during bouts of high-intensity cycling when compared to placebo treatment. Similar to Astorino et al, 2011 these studies both tested non-specifically trained subjects and used a CAFF dosage the same as, or very close to that of Whiles et al, 2006; Doherty et al, 2006 & Astorino et al, 2011. Also of importance Greer et al, 2006 tested subjects that were naive to CAFF and still found contradicting results. These equivocal data suggest that there is variation in subjects’ ability to improve performance with CAFF, which is possibly mediated by discrepancies in CAFF metabolism (Gonzalez, Kalow & Tang, 1992).
As a matter of fact Crowe et al, 2006 found CAFF may have been detrimental to performance resulting in a much slower time to reach peak power in the second exercise bout. However the exercise protocol differs between the studies and therefore it is possible that the subjects could have paced their efforts during the second exercise bout despite being instructed to do otherwise.
It is tempting to suggest that the ingestion of CAFF (5mg/kg) one hour prior to high-intensity exercise will increase the ability to produce peak power however more research is needed to further back up current findings. Furthermore, the studies being reviewed have their limitations. First, the findings can only be applied to power production via lower body exercise characterized by contractions of the knee flexors and extensors. The same findings cannot be said for upper body resistance or total body sports. Second, out of the 79 participants across the studies all of them were of younger generation and only 5 were female subjects therefore more research across a variety of populations is required. Finally it’s clear that the majority of power increases came from specifically trained subjects it seems this could have an advantage regarding CAFF effect on power production however more research on this subject is vital.
(Costill, Dalsky, & Fink, 1978) (Graham & Sprite, 1991) (Trice & Haymes, 1995) (Erickson, Schwarzkoff, & McKenzie, 1987) (Wiles, Coleman, Tegerdine, & Swaine, 2006) (Crowe, Leicht, & Spinks, 2006) (Greer, Morales, & Coles, 2006) (Doherty, Smith, Hughes, & R.C.R, 2004) (Gonzlaez, Kalow, & Tang, 1992) (Kilding, Overton, & Gleave, 2012)
5 Bibliography
Costill, D., Dalsky, G., & Fink, W. (1978). Effects of caffeine ingestion on metabolism and exercise performance. Medicine and science in sports and exercise, 155-158.
Crowe, M., Leicht, A., & Spinks, W.
(2006). Physiological and cognitive responses to caffeine during repeted, high-intensity exercise . International journal of sport nutrition and exercise metabolism, 528-544.
Doherty, M., Smith, P., Hughes, M., & R.C.R, D. (2004). Caffiene lowers perceptual response and increases power output during high-intensity cycling. Journal of sports science, 637-643.
Erickson, M., Schwarzkoff, R., & McKenzie, R. (1987). Effects of caffeine, fructose and glucose ingestion on muscle glycogen utilization during exercise. Medical science of sports and exercise, 579-583.
Gonzlaez, G. L., Kalow, F. J., & Tang, B. K. (1992). Bio-transformation of caffeine, paraxanthine, theobromine, and theophylline by cDNA-expressed human CYP1A2 and CYP2EA. Pharmacogenetics, 73-77.
Graham, T., & Sprite, L. (1991). Performance and metabolic responses to high caffeine dose during prolonged ecercise. Journal of applied physiology, 2292-2298.
Greer, F., Morales, J., & Coles, M. (2006). Wingate performance and surface EMG frequency variables are not affected by caffeine ingestion. Applied physiology, nutrition, and metabolism,
597-603.
Kilding, A., Overton, C., & Gleave, J. (2012). Effects of caffeine, sodium bicarbonate, and their combined ingestion on high-intensity cycling performance. International journal of sport nutrition and exercise metabolism, 175-183.
Trice, I., & Haymes, E. (1995). Effects of caffeine ingestion on exercise in duced changes during high-intensity, intermittent exercise. International journal of sports exercise, 37-44.
Wiles, J., Coleman, D., Tegerdine, M., & Swaine, I. (2006). The effects of caffeine ingestion on performance time, speed and power during a laboratory-based 1 km cycle time-trial. Journal of sports science, 1165-1171.