Caffeine, Exercise and Your Sleep: The Link Could be Sign. Different From What You Expect - Sleep Better W/ Caffeine?

Caffeine, Exercise and Your Sleep: The Link Could be Sign. Different From What You Expect - Sleep Better W/ Caffeine?

caffeine coffee ergogenic exercise health sleep sleep duration sleep quality stimulants

Coffee and exercise both effect sleep, but their effects don't simply add up. The study at hand does yet suggest that your preworkout coffee won't ruin your sleep.

I have to admit, the following are not results of peer-reviewed research, but with a 2x2 week design, participants being randomized to exercise (4 workouts per week) or be sedentary and to consume caffeine or placebo prior to exercise or rest, it looks methodologically complex, but sound and, more importantly, interesting enough to make it into the SuppVersity news ... I mean, it's about coffee ;-)

With that being said, the scientists, who were hopefully less biased than I am, required their subjects to refrain from any extra regular physical activity and or coffee / caffeinated beverage consumption outside of the conditioning/treatment sessions, in which they didn't drink coffee, but 350-mL of Gatorade with or without a rel. low dose of 3mg/kg caffeine.

You can learn more about coffee and caffeine at the SuppVersity

For Caffeine, Timing Matters! 45 Min or More?

Coffee - The Good, Bad & Interesting

Three Cups of Coffee Keep Insulin At Bay

Caffeine's Effect on Testosterone, Estrogen & SHBG

The Coffee³ Ad- vantage: Fat loss, Appetite & Mood

Caffeine Resis- tance - Does It Even Exist?

The authors' data analysis involved the usual mixed analysis of variance with treatment (placebo or caffeine) and condition (exercise or sedentary) as between subjects factors. In addition, time as the repeated measure, and the subjects' usual caffeine intake and BMI were included as covariates.

Figure 1: Mean sleep duration (h) in the different arms / phases of the 2x2 week RCT (O'Brien. 2016).

As the data in Figure 1 tells you, the statistical analysis yielded an independent main effect of
condition (sedentary/exercise) on the number of hours the subjects actually slept (this is not "time spent in bed"). In that, it did matter, whether the subjects worked with or without caffeine, but both, the effects of exercise (SED vs. EX | Figure 1), and as those of caffeine (see PLA vs. CAF | Figure 1) are not exactly what you probably expected:

• Effects of exercise - Subjects who exercised in the lab self-reported less time (hours) sleeping [F(1,18) = 4.5, p = 0.049] compared to sedentary. In that, there was a trend for an independent effect of treatment (placebo/caffeine) on hours slept (p = 0.08),
• Effects of caffeine - Subjects who received placebo self-reported less time (hours) sleeping compared those who received caffeine (that was not what you'd expect based on previous evidence). In that, there were no interactions by usual caffeine intake.

Now, one's sleep duration is only one out of several parameters that will determine whether or not you rise and shine refreshed; plus, since all subjects had average sleep times in the "green zone" of 6.5-8h per night, they were all sleeping enough - irrespective of exercise and/or caffeine. The parameter of actual interest is thus the subjects' subjective sleep quality and its relationship to their perceived tiredness in the AM / over 24h, which were both assessed with questionnaires in the study at hand.

Figure 2: Sleep quality and perceived tiredness over the course of the 2x2 week RCT (O'Brien. 2016).

For the former, i.e. the subjects' sleep quality, the data in Figure 2 signifies that here was a significant time x treatment x condition interaction on overall sleep quality [F(11,198) = 1.92; p = 0.038]. In that,  the subjects' sleep quality decreased over time in subjects who exercised compared to condition controls (sedentary). In contrast to what you'd expect, though, it were not the subjects who worked out and consumed caffeine who had the lowest sleep quality, but those "who exercised and received placebo [who] had the lowest overall average sleep quality" (O'Brien. 2016).

What may come as a surprise is that this decline in sleep quality had no effect on the subjects' perceived tiredness (Figure 2, right), which showed a main effect of time for ‘Body Feels Tired’ [F(11, 154) = 2.1; p = 0.026], but no treatment (placebo/caffeine) or condition (sedentary/exercise) interactions - which is unquestionably odd. About as odd, as the misleading statement that "[p]oorest sleep quality ratings associated with caffeine and exercise" (O'Brien. 2016) from the scientists' own summary of the results. Now, don't get me wrong. This statement is correct, but only if we are talking about the individual effects of exercise / sedentary and caffeine / placebo, on their own. The way O'Brien et al. phrased it, does however appear to suggest that the subjects' sleep was worst during the exercise + caffeine trials... Now, that, in turn, is what you probably expected the study to show, but another brief glance at the data in Figure 2 (left) confirms: caffeine did not mess with the subjects' sleep quality. In fact, the group with the most stable sleep quality are the sedentary coffee drinkers . eventually, you could thus argue that they had the best sleep quality!

High Dose Caffeine Restores Insulin Sensitivity and Limits Sugar-Induced Total + Visceral Fat Gain . That's in contrast to the still prevalent message that caffeine would ruin your insulin sensitivity | more

Bottom line: As the authors point out, "[e]xercise and caffeine did not have the hypothesized results on sleep quality and duration" (O'Brien. 2016). Instead of improving the sleep quality of the subjects, as it has been observed previously in both, middle-aged and older adults (Yang. 2012) and young healthy sleepers (Flausino. 2012), exercise clearly reduced the young subjects' sleep quality in the study at hand. As O'Brien et al. point out, this may have been a function of the novelty of the exercise and subsequent "physical discomfort that disrupted sleep quality and duration" of the previously untrained subjects in the study at hand, so that the results would change over time / be different if the study had used trained individuals.

Another important subject characteristic that may have "messed" with the results were the sujects' individual habitual caffeine consumption (100mg/day on average). Even though their habitual intakes were low, the fact that caffeine did not, as it did in previous studies, per se mess with the subjects' sleep quality, but rather improved it, could, as O'Brien et al. suggest, be due to "[w]ithdrawal reversal" of which the scientist argue that it appears to be "the primary action mechanism of caffeine [in the study at hand]" (O'Brien. 2016). Practically speaking, this would mean that "[r]eversing [the] negative state [of being on caffeine withdrawal] through caffeine administration improved [not decreased the subjects'] sleep quality and duration" (O'Brien. 2016 | my emphasis). How realistic this assumption is does yet appear questionable, with std. deviations of <50mg/day, the subjects don't seem to be caffeine junkies and with a dosage of only 3mg/kg per day (all subjects were normal weight, so that's probably in the 200-300mg range) switching from a caffeine to a no-caffeine group in the 2nd of the 2x2 week phases doesn't appear to be likely to induce significant "caffeine withdrawal", either. I am thus doubly curious to see the (hopefully) full dataset, when this intriguing study is eventually published (also because the the caption of Figure 1 in the "FT" says that there was no interaction with habitual caffeine intake for sleep duration, at least). In the mean time, I'd suggest you simply listen to your body. The effects of exercise and caffeine on one's sleep are, after all, just as so many things, highly individual | Comment!

References:

• O’Brien, E, et al. "Caffeine and Exercise Affect Sleep Duration, Quality and Perceived Tiredness." Department of Exercise and Nutrition Sciences---University at Buffalo, Buffalo, NY (Poster presentation).
• Yang, Pei-Yu, et al. "Exercise training improves sleep quality in middle-aged and older adults with sleep problems: a systematic review." Journal of physiotherapy 58.3 (2012): 157-163.

High Dose Caffeine Restores Insulin Sensitivity and Limits Total as Well as Visceral Fat Gain Due to High Sugar Diets

High Dose Caffeine Restores Insulin Sensitivity and Limits Total as Well as Visceral Fat Gain Due to High Sugar Diets

caffeine coffee fat gain glucose management health high sugar insulin sensitivity lose fat obesity sugar type II diabetes visceral fat

Yes, the study at hand is on caffeine, but the results are relevant for coffee, too.

A decade ago, the medical community though coffee would dehydrate you, would make you insulin resistant and would increase your risk of heart disease. Recent studies show that coffee does not negatively affect your hydration status (Killer. 2014), that higher coffee consumption is associated with reduced diabetes risk and increasing your coffee consumption can reduce your risk of T2DM (Akash. 2014) and that a "daily intake of ∼2 to 3 cups of coffee appears to be safe and is associated with neutral to beneficial effects" on coronary heart disease, congestive heart failure, arrhythmias, and stroke (O'Keefe. 2013).

Against that background it may not be as surprising as it would have been 10 years ago that Joana C. Coelho, et al. (2016) found caffeine to be able to restores insulin sensitivity and glucose tolerance in high-sucrose diet rats. And yet, I personally believe that it is still worth pointing out the results of this study as the high sucrose diet the mice were fed is the same "high sugar diet" about which you will read all over the news that it is to blame for the obesity and diabetes epidemic.

You can learn more about coffee and caffeine at the SuppVersity

For Caffeine, Timing Matters! 45 Min or More?

Coffee - The Good, Bad & Interesting

Three Cups of Coffee Keep Insulin At Bay

Caffeine's Effect on Testosterone, Estrogen & SHBG

The Coffee³ Ad- vantage: Fat loss, Appetite & Mood

Caffeine Resis- tance - Does It Even Exist?

Against that background, it is particularly interesting to take a closer look at the data from Coelho's study, because it is the first to actually provide a valid explanation for the observed improvements in glucose sensitivity in response to the ingestion of caffeine.

Figure 1: 16-wk food intake, weight gain, fat gain and visceral fat gain according to caffeine intake (Coelho. 2016).

Now, the bad news is that significant effects were only observed for the highest dose of caffeine, ie..e 1g/L drinking water. That appears to be ridiculously high, but is in fact only "very high". If you do take into consideration that a wistar rat consumes only 100 ml/kg body weight per day, that's a dosage equivalent of 100 mg/kg for a rodent and thus ~16 mg/kg for a human being or ~6-7 cups of coffee (over a 24h period).

University of Memphis: Caffeine can help control the increase in blood lipids and oxidation after inhaling (10 minutes) a high calorie + high fat milk shake, controlled trial involving twelve healthy men shows (Crone. 2016).

Yes, the dosage is high, but actually less may have more benefits, and...  the most relevant benefits (reduced fat gain) were seen at a dosage that would be equivalent to only 4-5 cups of coffee, which happens to be roughly what epidemiological studies show to be in the zone of maximal benefits. Don't mistake this as a recommendation to guzzle liters of coffee, though... and that even if another recent study shows that 400mg of caffeine will lower the fatty acid onslaught and oxidation 12 men experience after consuming a large high fat milk-shake (Crone. 2016)... and speaking of coffee: you may also want to make sure to get a dark roast, because the latter has just been found to improve glucose metabolism and redox balance even if it is low in caffeine (Di Girolamo. 2016). 

While I am not sure how healthy the chronic consumption of these amounts of caffeine actually is. I am aware of several people who get their 6-7 cups of regular coffee per day and are in perfect health. With that being said, the latter may be at least partly due to the the highly beneficial effects of caffeine on the expression of glucose transporter 4 (GLUT4) and insulin receptor expression and phosphorylation (not shown in Figure 2) in the visceral fat depots of coffee connaisseurs.

Figure 2: Effects of different doses of caffeine on GLUT4 and insulin receptor expression in rats (Coelho. 2016).

The above elevations were accompanied by profound increases in protein kinase B (Akt) expression and activity, as well - an observation the scientists regard as being evidence of the fact that "[c]hronic caffeine administration improved whole-body glucose homeostasis and insulin signaling pathways in adipose tissue" (Coelho. 2016).

This conclusion cannot be questioned. What can be questioned, though, is the scientists assumption that this would occur only with high doses of caffeine and in response to increases in GLUT4 and insulin receptor expression in the visceral fat. Why's that? Well take a look at the figure in the bottom line: it shows that significant improvements in glycemia were improved at all dosages. The latter wouldn't have been possible if the lower dosages wouldn't have had an effect on glucose uptake, as well. Whether that's an effect in muscle cells (which would be great), needs further investigation. The previously discussed effects of caffeine on muscle glycogen storage (learn more), on the other hand, would suggest just that: an effect on skeletal muscle, and or a reduction in gluconeogenesis which could, among other things, be triggered by coffee's / caffeine's ability to inhibit the reactivation of glucocorticoids by 11β-hydroxysteroid dehydrogenase type 1" (Atanasov. 2006).

As you can see sign. improvements in glycemia occured even with the lowest amount of caffeine in the drinking water. And that in spite of the fact that the GLUT4 and insulin receptor levels in the visceral fat did not increase significantly... well, maybe those in the rodents' muscle did?

Bottom line: I am not suggesting that the rodent study at hand would provide enough evidence to suggest that everyone should drink at least 4 cups of high caffeine coffee per day. What I do suggest, however, is that the study at hand provides more evidence on potential mechanisms that explain why coffee drinkers are plagued less often by metabolic disease.

With that being said, I would like to remind you that the abuse of caffeine to combat a lack of sleep and/or overtraining may make you dig a deep black hole out of which you will be able to crawl only within weeks of abstinence... and I am talking about abstinence from caffeine and exercise, assuming that it was the combination of both that got your into trouble | Comment on Facebook!

References:

• Akash, Muhammad Sajid Hamid, Kanwal Rehman, and Shuqing Chen. "Effects of coffee on type 2 diabetes mellitus." Nutrition 30.7 (2014): 755-763.
• Atanasov, Atanas G., et al. "Coffee inhibits the reactivation of glucocorticoids by 11β-hydroxysteroid dehydrogenase type 1: A glucocorticoid connection in the anti-diabetic action of coffee?." FEBS letters 580.17 (2006): 4081-4085.
• Coelho, Joana C., et al. "Caffeine Restores Insulin Sensitivity and Glucose tolerance in High-sucrose Diet Rats: Effects on Adipose Tissue."
• Crone, et al. "Impact of Meal Ingestion Rate and Caffeine Coingestion on Postprandial Lipemia and Oxidative Stress Following High-Fat Meal Consumption." Journal of Caffeine Research (2016): Ahead of print. DOI: 10.1089/jcr.2016.0004.
• Di Girolamo, Filippo Giorgio, et al. "Roasting intensity of naturally low-caffeine Laurina coffee modulates glucose metabolism and redox balance in humans." Nutrition (2016).
• Killer, Sophie C., Andrew K. Blannin, and Asker E. Jeukendrup. "No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population." PloS one 9.1 (2014): e84154.
• O'Keefe, James H., et al. "Effects of habitual coffee consumption on cardiometabolic disease, cardiovascular health, and all-cause mortality." Journal of the American College of Cardiology 62.12 (2013): 1043-1051.

Caffeine Keeps You Going When You'd Usually Rack the Weight - Does That Cause an Increase in Muscle Damage?

Caffeine Keeps You Going When You'd Usually Rack the Weight - Does That Cause an Increase in Muscle Damage?

caffeine CK coffee lactate performance rhabdomyolysis training

With only 65mg of caffeine, an espresso provides only ~12.5% of the amount of caffeine used in the study at hand.

If you've kept an eye on the latest caffeine research you may have noticed that there's an increasing number of studies that fails to find significant performance enhancing effects of caffeine during resistance training sessions (Trevino. 2015). Does this mean that caffeine, a substance that is by the way on the World Anti-Doping Agency's list of prohibited substances useless for gymrats? Certainly not.

One thing most of these studies have in common is that they tested the subjects' strength or power production during short workouts. Studies that investigate the effects of caffeine in higher volume contexts, on the other hand (e.g. Lang. 2015; Thomas. 2015), confirm that caffeine is rightly the most (ab-)used ergogenic among fitness enthusiasts.

You can learn more about coffee and caffeine at the SuppVersity

For Caffeine, Timing Matters! 45 Min or More?

Coffee - The Good, Bad & Interesting

Three Cups of Coffee Keep Insulin At Bay

Caffeine's Effect on Testosterone, Estrogen & SHBG

The Coffee³ Ad- vantage: Fat loss, Appetite & Mood

Caffeine Resis- tance - Does It Even Exist?

One thing that has recently caught my attention on Facebook is the claim that the performance enhancing effects of caffeine put you at risk of rhabdomiolysis, i.e. the potentially dangerous breakdown of muscle tissue. In theory, it'd appear logical to assume that an agent that has repeatedly been proven to significantly lower the perceived exertion/fatigue as well as muscle pain during exercise could lead to a greater degree of muscle damage during exercise.

Figure 1: Graphical overview of the experimental design of Ribiero's study (Ribiero. 2016).

To test the hypothesis that acute caffeine ingestion could attenuate leg power, and increase blood lactate at the expense of increased muscle damage, researchers from the Federal University of Rio de Janeiro recruited six male pro handball athletes who layed in the first division of the Brazilian National League of Handball (HBNL).

"All of them had at least 5 years of experience in the sport and trained for about 4 hours a day, 4-5 days a week. No athlete had a previous medical history of cardiopulmonary disease or used any medication during the study. The athletes reported intake of ~ 60 mg of caffeine per day (~ 1 cup of coffee)" (Ribiero. 2016).

In a randomized, placebo-controlled, double-blind crossover study, the subjects reported to the laboratory at two occasions after an 8-h fast and at least 24h of caffeine abstinence. 60 minutes after having a standardized breakfast, which consisted of bread, white cheese, and orange juice (CHO: 87 g, 348 kcal; PTN: 13.5 g, 54 kcal; LIP: 7 g, 63 kcal; Total: 465 kcal), they consumed either placebo (PLA), or caffeine (CAF; 6mg/kg body weight) and remained seated for another 60 minutes.

But this is not resistance training! While you're absolutely right, jumping is at least as notorious for producing muscle damage as regular resistance training. It is thus unlikely that leg presses or squats would have produced a greater degree of muscle damage than this intense VJ protocol.

After the 60-minute delay during which the serum caffeine levels rose to peak values (see previous SuppVersity article), they performed a short warm-up and a standardized vertical jump test the scientists describe as follows:

Figure 2: Mean leg power during VJ (Ribiero. 2016).

"The VJ performance was evaluated by the jump platform System Optical (Cefise®, São Paulo, Brazil). This equipment consists of a laptop with the software "Jump System" (version 1.0, São Paulo, Brazil), connected by a cable to a resistive (or capacitive) platform (equipped with infrared optical sensors). The timer software is triggered by the feet of the subject at the moment of release from the platform, and will be stopped at the moment of touchdown. This equipment has the same principle of “Ergojump” to inform the flight time (ms) and contact (ms). 

The error of measurement, when compared with film analysis has been reported to be in the order of ± 2% (18). The athlete was positioned, barefoot, in the interior of the platform and the jumps were performed starting from a standing position until approximately at an angle of 90° knee, using help from upper limbs at the time of the VJ execution" (Ribiero. 2016).

The VJ data were analyzed by average leg power (Watts/Kg) generated by the athletes. In that, the scientists separated the total number of vertical jumps into tertiles, so that they could have an understanding of the behavior of the jumps in the 1st tertile (i.e., theoretically better performance), in the 2nd tertile (i.e., theoretically an average performance), and 3rd tertile (i.e., theoretically a drop in performance).

Your muscle is not the only thing that could be overtaxed - Even though the ability to perform more sets / work out more intensely / longer may not have affected the primary marker of muscle damage in the study at hand, the chronic consumption of high doses of caffeine may still pose a risk to your central nervous system and contribute to sympathetic overtraining. Therefore I'd still recommend you stick of max. 400-600 mg caffeine per day and, instead of increasing the dosage, when it stops working, take a "caffeine break" whenever you stop noticing the "caffeine spike".

This allowed Ribiero et al. to make comparisons between groups and to assess the effects of supplementation. Effects of which the data in Figure 3 tells you that they became evident only in the latter tertile of jumps:

Figure 3: Nonlinear regression analyses (polynomial regression 3rd order). Leg of the power generated in each sets of athletes with tertiles in placebo (PLA) and caffeine (CAF) trials (Ribiero. 2016).

As you can see in Figure 2, the subjects hit the wall in said third tertile in the placebo trial. In the supplement trial, on the other hand, the performance decline was significantly ameliorated - not only, but especially during the first and second set (black squares and white circles). This effect becomes even more obvious when you take a look at the leg power the subjects exerted on the jump platform during the jumps in the 1st, 2nd and 3rd tertile (plotted in Figure 2): compared to the use of placebo caffein improved the leg power the of athletes in the 3rd tertile (p <0.05) by 5.23%.

At the same time, however, it lead to a highly significant increase in blood lactate levels (+42.59%) after the execution of vertical jump test (p <0.05). In contrast to what the initially discussed hypothesis would suggest, though, this increase in lactate was not accompanied by significant increases in serum CK levels of the athletes (see Figure 4).

Figure 4: On average, the increase in CK was even lower in the caffeine trial - albeit not significantly (Ribiero. 2015).

So what does that mean? Well, the most obvious answer certainly is that using caffeine to boost your performance beyond "natural limits" is not going to increase your risk of rhabdomiolysis. On the other hand, the study doesn't say anything about the effects on the central nervous system and whether your CNS, not your muscle, could be overtaxed by "going beyond failure" with caffeine.

The potential negative effects of chronic caffeine consumption on the central nervous is a problem I've mentioned in the red box and discussed in previous articles about caffeine.

Unfortunately, this problem has not been sufficiently studied, yet. So, if you're looking for a supplement related topic for your master thesis, boys and girls, the effects of chronic pre-workout caffeine consumption at different dosages on the central nervous system could be just the topic you've been looking for ;-) | Comment on Facebook!

References:

• Lang, K., and E. B. LaFountaine. "Effects of caffeine as an ergogenic aid on weight lifting regimes in male collegiate athletes." International journal of exercise science: Conference proceedings. vol. 12. no. 1. 2015.
• Thomas, Gabrielle. Is coffee an effective pre-workout drink?–The effects of ingesting naturalistic doses of caffeine on one-repetition maximum muscular strength and muscular endurance in females. Diss. Cardiff Metropolitan University, 2015.
• Ribiero, et al. "Caffeine attenuates decreases in leg power without increased muscle damage." Journal of Strength and Conditioning Research (2016): Publish Ahead of Print | DOI: 10.1519/JSC.0000000000001332
• Trevino, Michael A., et al. "Acute Effects of Caffeine on Strength and Muscle Activation of the Elbow Flexors." The Journal of Strength & Conditioning Research 29.2 (2015): 513-520.

Coffee Beats Caffeine in the Gym: More Reps + Higher Total Volume on Squats Due to Ingredients Other Than Caffeine

Coffee Beats Caffeine in the Gym: More Reps + Higher Total Volume on Squats Due to Ingredients Other Than Caffeine

bench press caffeine chest coffee decaf decaffeinated decaffeinated coffee leg traning performance squats

You don't necessarily have to bring fresh beans to the gym. A simple Nescafé instant coffee will serve the purpose, study shows. And it's going to work better than equal doses of straight caffeine.

As a SuppVersity reader you will know that coffee is much more than a brown liquid that contains caffeine. Many of its proven health effects I have discussed here and in shorter news items on Facebook are after all related to the combination of anti-oxidant and stimulant agents in coffee - a brew that is so much more than just the sum of it parts.

Against that background it is only logical that Darren L. Richardson and Neil D. Clarke from the Department of Applied Sciences and  at the Faculty of Health and Life Sciences of the Coventry University in the UK wanted to expand on the previously reported results by Trexler et al. (2015 | previously mentioned at the SuppVersity).

You can learn more about coffee at the SuppVersity

For Caffeine, Timing Matters! 45 Min or More?

Caffeine Helps PWO Glycogen Loading

Three Cups of Coffee Keep Insulin At Bay

Caffeine's Effect on Testosterone, Estrogen & SHBG

The Coffee³ Ad- vantage: Fat loss, Appetite & Mood

Caffeine Resis- tance - Does It Even Exist?

Trexler et al. found that coffee improved leg press 1-RM performance to a greater extent than caffeine, while both coffee and caffeine attenuated the reduction in total work performed compared with placebo. Accordingly, Richardson and Clarke started their research, which was a randomised, latin-square, crossover, placebo-controlled trial, in which each subject attended the strength and conditioning suite on six occasions, with the hypothesis that the ingestion of coffee would exhibit at least some advantages over a equally dosed caffeine "placebo".

Figure 1: Graphical illustration of the experimental protocol on all five test occasions (Richardson. 2016).

To test this hypothesis, the researchers recruited nine resistance trained males [(Mean±SD age: 24±2 years, weight: 84±8 kg, height: 180±8 cm, 1-RM for the squat (135±28 kg) and bench press (102±20 kg)]. Each subject attended the strength and conditioning suite on six occasions, the first being a familiarisation session to establish one repetition maximum (1-RM) for the squat and bench press, before they completed five sessions of the same the experimental resistance training protocols.

"Trials were performed within half an hour on separate days to ensure an accurate comparison of strength and to limit strength fluctuations due to the effects of circadian variation (Duncan. 2011). Trials were separated by at least two days in order to allow recovery and to ensure complete caffeine washout. As caffeine has a highly variable half-life in healthy individuals of between 1.5-9 hours (Syed. 2005) subjects were instructed to avoid caffeine ingestion for a minimum of 12 hours and strenuous exercise for 24 hours prior to each trial to avoid fatigue (Beaven. 2013).

The actual exercise protocol consisted of squats and bench presses at 60% 1-RM until failure.  Each subject performed the exercise protocol following the ingestion of...

• 0.15 g/kg caffeinated coffee (COF; 3.4g per 100g coffee = 5.1g/kg body weight), 
• 0.15 g/kg decaffeinated coffee (DEC; 5mg caffeine per kg coffee = almost zero), 
• 0.15 g/kg decaffeinated coffee plus 5 mg/kg anhydrous caffeine (D+C), 
• 5 mg/kg anhydrous caffeine (CAF), or 
• a placebo (PLA; 5 mg·kg-1 maltodextrin from MyProtein, Manchester, UK).

Decaf? Well, the reason the scientists did use both, straight caffeinated and decaffeinated coffee with caffeine should be obvious: Unlike the comparison of Nescafé original (3.4g of caffeine per 100g) vs. its decaffeinated version coffee, the comparison of DEC with D+C ensured identical polyphenol concentrations in the decaf-base.

How to make the most of coffee or caffeine pills... time them correctly. If you haven't done so or cannot remember the conclusions I have drawn in my article on caffeine / coffee timing, I highly suggest you head over to this SuppVersity Classic to (re-)read it!

That's something which cannot be guaranteed for the caffeinated vs. decaffeinated versions of the same brand of coffee.

"[In all] trials [coffee poweder and caffeine] were dissolved in 600 ml of hot water (68.9±2.5ºC) and served in mugs. The anhydrous caffeine and placebo trials were provided in capsule form (two opaque gelatine capsules) and ingested with 600 ml of water (16.4±3.8ºC). At the start of each trial, subjects had a maximum of 15 minutes to fully consume either the treatment beverage or capsules and water and were then required to rest for the remainder of the hour, after this time the warm up began. [...]  A 24-hour dietary recall was completed by each subject during the familiarisation session, and was photocopied and handed back to the subjects in order for the same diet to be followed prior to subsequent trials" (Richardson. 2016).

Let me briefly do the math for you: With the dosages and body weights mentioned before, subjects in all caffeine groups ended up receiving roughly the same amount of caffeine (when there was caffeine in the beverage), namely: COF: 433±40 mg, DEC: 2±0 mg, D=C: 425±39 mg, CAF: 425±39 mg.

Figure 2: Changes in total weight lifted in response to the 5 treatments (Richardson. 2016).

Against that background it is all the more interesting that the coffee and decaf + caffeine group had a significant edge during squats (see Figure 2, right). "Isn't it strange, then that we don't see the same benefit on the bench?", you may be asking yourself, now... No, it isn't! Neither Beck, et al. (2008) nor Hendrix et al. (2010, bench press was part of a circuit training her) found benefits of caffeine supplementation on bench press performance in trained individuals, in similarly designed studies.

Total flavonoid and nonflavonoid contents of all coffee and instant cappuccino brews, prepared only with water. Results are expressed as mg GAE/L ± SD (Niseteo. 2012).

How healthy is decaffeinated coffee? The chemicals that were originally used to remove the caffeine from the beans are no longer a problem. Furthermore, studies show that decaffeinated coffee contains on average (there are differences between brands, obviously) about as many anti-oxidants as its regular cousin (Niseteo. 2012). Decaf has also been shown to have dose-dependent beneficial effects of decaffeinated coffee on endothelial function in healthy subjects (Buscemi. 2009) and similar effects on T2DM risk markers in experimental (Wedick. 2011) and epidemiological studies (Huxley. 2009).

Yet, even though decaffeinated coffee is much better than its reputation, buying it only to reintroduce caffeine for performance purposes doesn't really make sense if it's not done in a scientific study to differentiate the effects of caffeine and other coffee ingredients.

Duncan, et al. (2011) who conducted a very similar study 3 years later, however, found performance increments for the upper body, too (~10% increased total volume in the caffeine trial). Whether this difference to the previously mentioned studies by Beck et al. and Hendrix, et al. can be explained by the fact that Duncan et al. required their likewise trained subjects to be "only moderate caffeine users (ingesting approximately 200 mg·d-1, range 169-250 mg·d-1)" (Duncan. 2011), remains to be seen. While this is in fact ~100mg less than the average intake of the subjects in the study at hand, i.e. Richardson & Clarke (2016), other studies appear to suggest that the habitual caffeine intake has less influence on the performance effects than you would think.

Figure 3: Individual effect on weight lifted during both trials (left) and mean felt arousal (right | Richardson. 2016).

An alternative, but similarly speculative explanation for the differences may be that the effects of caffeine on upper body and eventually less taxing exercises is not as relevant as it is for squats. Thus the overall effect could be more pronounced during leg exercises and the benefits for bench presses and co too small to reach statistical significance in view of the fact that all studies appear to suggest that there are hyper- (like the guy on top of Figure 3, left) and almost-non-responder which mess with the statistical significance of the data.

Caffeine-Resistance? Genetic & Environmental Factors Determine If You Feel or Don't Feel the "Boost" | Plus: 11 Non-Genetic Factors That In- & Decrease Caffeine's Effect | more

Whatever the reason, performance increase is performance increase! "Coffee and decaffeinated coffee plus caffeine have", as Richardson & Clarke point out "the ability to improve performance during a resistance exercise protocol, although possibly not over multiple bouts" (Richardson. 2016). What they forget to mention, though are the important differences between the effects of coffee or re-caffeinated decaf, on the one, and caffeine, alone, on the other hand. If we 'correct' that, we have to conclude that Richardson and Clark have been able to show that the real deal, i.e. coffee with all its original or reintroduced ingredients, and not its distilled main ingredient, caffeine, in pill or powder form should be a resistance trainee's stimulant of choice | Comment on Facebook!

References:

• Beaven, C. Martyn, et al. "Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance." Applied Physiology, Nutrition, and Metabolism 38.6 (2013): 633-637.
• Beck, Travis W., et al. "The acute effects of a caffeine-containing supplement on bench press strength and time to running exhaustion." The Journal of Strength & Conditioning Research 22.5 (2008): 1654-1658.
• Buscemi, S. I. L. V. I. O., et al. "Dose-dependent effects of decaffeinated coffee on endothelial function in healthy subjects." European journal of clinical nutrition 63.10 (2009): 1200-1205.
• Duncan, Michael J., and Samuel W. Oxford. "The effect of caffeine ingestion on mood state and bench press performance to failure." The Journal of Strength & Conditioning Research 25.1 (2011): 178-185.
• Hendrix, C. Russell, et al. "Acute effects of a caffeine-containing supplement on bench press and leg extension strength and time to exhaustion during cycle ergometry." The Journal of Strength & Conditioning Research 24.3 (2010): 859-865.
• Huxley, Rachel, et al. "Coffee, decaffeinated coffee, and tea consumption in relation to incident type 2 diabetes mellitus: a systematic review with meta-analysis." Archives of internal medicine 169.22 (2009): 2053-2063.
• Niseteo, Tena, et al. "Bioactive composition and antioxidant potential of different commonly consumed coffee brews affected by their preparation technique and milk addition." Food chemistry 134.4 (2012): 1870-1877.
• Syed, Shariq A., et al. "Multiple dose pharmacokinetics of caffeine administered in chewing gum to normal healthy volunteers." Biopharmaceutics & drug disposition 26.9 (2005): 403-409.
• Trexler, Eric T. Effects of creatine, coffee, and caffeine anhydrous on strength and sprint performance. THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL, 2015.
• Wedick, Nicole M., et al. "Effects of caffeinated and decaffeinated coffee on biological risk factors for type 2 diabetes: a randomized controlled trial." Nutrition journal 10.1 (2011): 1.

Caffeine + Green Tea = Plus 10% Fat Oxidation & Energy Expenditure at Rest and During Sprint Interval Exercise

Caffeine + Green Tea = Plus 10% Fat Oxidation & Energy Expenditure at Rest and During Sprint Interval Exercise

caffeine coffee EGCG energy expenditure fat burner fat oxidation green tea GTE lose fat metabolic rate REE

From a health perspective it may be good that green tea does not contain all-too much caffeine. From a fat loss perspective, it clearly lacks caffeine.

When it comes to dietary supplements, people like to pay tons of money for unproven ingredients with funky names and dubious or non-existent safety profiles; agents that have been scientifically proven to work, are safe and cheap, on the other hand, are non-sellers or at least considered to be non-effective.

Obviously, I cannot really explain why that is the case (I suspect it is because people effect drug-like effects without drug-like side-effects from supps and are thus always on the lookout for the "next big"... hoax), I can tell you, though, that a recent study that is going to be published in one of the upcoming issues of the Journal of Strength and Conditioning Research (Jo. 2015) shows that caffeine and green tea, two supplements that belong to the previously described category, are everything but useless.

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In said study, Edward Jo and colleagues investigated the effects of a caffeine + green tea polyphenol mix (250mg caffeine + 400mg of a green tea extract with 50% EGCG and 5mg of caffeine per serving) on (a) metabolic rate and fat oxidation at rest, as well as following a bout of sprint interval exercise (SIE) and (b) the performance during a standardized sprint-interval test.

The study was a double-blind, randomized, placebo-controlled, crossover study that involvd 12 subjects (male: n=11; female:1 n=1) whose antroprometric data, i.e "body mass=76.1±2.2 kg; height= 169.8±1.6 cm; BMI= 22.7±3.0 kg/m2; body fat %= 21.6±2.0% [DXA data]" (Jo. 2015), already tell you that they were healthy recreationally active, but not necessarily athletic (it may be worth mentioning that they were relatively stim-naive with an intake of < 201mg of caffeine per day).

Figure 1: Energy expenditure (kcal/h) and fat oxidation (g/day) measure before (at rest) and during (during SIE) the sprint interval exercise 10 and 55 minutes after the ingestion of caffeine + GTE or placebo (Jo. 2015).

During the two testing sessions at the Human Performance Research Laboratory of the California State Polytechnic University, the subjects' resting energy expenditure (REE) was measured for 45 minutes starting 10 minutes after the ingestion of the aforementioned caffeine + polyphenol mix - a mix that was consumed on an empty stomach after an 8-h overnight fast (don't be fooled by the way the scientists report their data in "g/day" and kcal/day - I changed the latter, already but the values for fat in g would have become to small - we are talking about 45 + 30 min and a 24h measurement here).

Don't confuse increases in fat oxidation w/ fat loss: I guess we have to credit the supplement industry for propagating the myth that the ratio of fat to glucose you were burning was in anyway directly related to losing body fat. I am not sure how often I've written this on this blog or told someone in the gym: that is not the case. You can burn 20% more fat and still store more body fat if you increase your energy intake from exactly enough to already too much. The connection between fatty acid oxidation which would actually be a better term for the phenomenon we are talking about is complicated and a decreasing respiratory exchange ratio, i.e. a reduction of the ratio of glucose to fat that's used to fuel your metabolism is not a reliable predictor of fat loss.

After the initial 45-minutes, during which the subjects' resting energy expenditure had been measured, the subjects were placed on a computer-integrated cycle ergometer on which they performed a standardized 30 minute sprint interval exercise (SIE) protocol., the scientists describe as follows:

"Sprint-Interval Exercise Protocol. The SIE protocol was performed on the Velotron DynaFit Pro cycle ergometer and comprised of four 30-second maximal effort intervals each separated by 5 minutes of low-intensity, constant workload cycling (Figure 2). First, the ergometer was properly adjusted for the subject. Adjustment specifications for each subject was recorded during their familiarization visit and repeated for all experimental trials. Subjects initiated the SIE protocol with a 5-minute interval of low-intensity cycling at a constant workload of 75W. Immediately after, subjects cycled with maximal effort for 30 seconds against an added resistance that is 7.5% of BW for males and 7.2% for females. These two intervals were repeated three additional times. After the last 30-second sprint interval, the subjects performed an additional low-intensity 75W interval plus an extra 3 minutes of cool-down at a constant workload of 30W. The total duration of the SIE protocol was 30 minutes" (Jo. 2015).

A workout that had little effect on the effect of the caffeine + green tea combo which did, as you can see, when you compare the "at rest" and "during SIE" values in Figure 1, increase the energy at rest and during sprint interval training to a similar extent. More specifically, the increase in energy expenditure and fat oxidation was - within the margin of inter-individual variability - in the range of +10% during both conditions.

Figure 2: Illustration of the sprint interval exercise test performed 55 min after ingesting the supplement (Jo. 2015).

In view of the fact that we may safely assume that this effect should last for at least 2-3h this can be a practically relevant effect if it is complemented by a reduced energy intake and a caloric deficit. If the latter is not present, even the extremest increases in fat oxidation and energy expenditure will fizzle out and be as irrelevant as the effect of the caffeine + green tea combination on exercise average and peak power (W) during the sprint training, Jo et al. observed in their study... and "Yes!", that is disappointing, but in view of the low dose of caffeine and the non-existent effects of green tea on performance during a test like this not really surprising.

Did you know this SuppVersity Calssic? "Post-Workout Coffee Boosts Glycogen Repletion by Up to 30% and May Even Have Sign. Glucose Partitioning Effects | learn more!

Bottom line: I admit, they certainly sound less exciting as the latest exotic herb from the rain-forest or a substance that is listed only under its funky chemical name on the label, but unlike your average "innovative breakthrough metabolic activator" caffeine and green tea will deliver. The 10% increase in metabolic rate and the accompanying increase in fat oxidation won't make you lose slabs of body fat, but the effects are pronounced enough to expect a measurable effect on the success of your next diet / cut. A cut, by the way, that will still require a significant reduction in energy intake, even if your energy expenditure and fat oxidation. So, don't be a fool and confuse a 10% increase in fat oxidation w/ a 10% increase in fat loss that occurs in the absence of dieting on an ad-libitum diet | Comment!

References:

• Jo et al. "Dietary Caffeine And Polyphenol Supplementation Enhances Overall Metabolic Rate And Lipid Oxidation At Rest And After A Bout Of Sprint Interval Exercise." Journal of Strength & Conditioning Research: Post Acceptance: November 23, 2015. doi: 10.1519/JSC.0000000000001277