Drinking strong coffee before exercising increases fat-burning, new study finds
> Subjects ingested 3 mg/kg of caffeine or a placebo at 8am and 5pm
3mg/kg is over 250mg of caffeine for an average weight man. Twice a day makes that 500mg.
An 8.4oz can of Red Bull contains 80mg of caffeine. They were giving these people an amount of caffeine equivalent to 6 cans of Red Bull. Not a perfect comparison because Red Bull contains other ingredients, but that's still a lot of caffeine. For another point of reference, that's 2.5 shots of 5 hour energy (200mg caffeine per bottle).
To top it off, the subjects were caffeine-naive, so they had no caffeine tolerance. They must have been feeling extremely energetic.
No wonder they burned more fat. I'm not sure this is going to translate to your casual coffee drinker or someone with a high caffeine tolerance.
My favorite thing about 'study finds' articles on HN is that I get to read the comments and see people instantly tell me why the article (or sometimes paper as well) is terrible.
I mean this sincerely too, since it's a very low-effort and quick way to find what is often some pretty critical flaws in the presented conclusions.
This is not surprising to anyone who has ever walked into a GNC, or other health food store... is it even news? They’ve been selling shit like “redline” for many years to do exactly this.
Power fat burner: caffeine + blood thinner. That’s most of what things like redline do. Is it going to work if you don’t exercise? Nope, but it sure as hell does help if you are exercising.
I’d really only recommend it to people focused on losing a lot of weight. If you’re trying to lose 10lbs it’ll never make a difference. If you’re trying to lose 100lbs though, then yeah, 6-12 months worth of slightly increased metabolic rate will probs have a net positive affect.
This past year I've been doing a lot of heavy manual labor; excavating large areas using a pick axe and shovel, hauling it away in a wheel barrow. And moving large ~200lb granite boulders in a wheel barrow ~1/3rd a mile up a slight grade from a nearby mountain.
At the same time I started drinking a strong pot of Earl Gray tea every morning to try get my butt in gear and outside in the dirt quicker. Normally I'm not a caffeine user. For the first week of this, my teeth would chatter and hands shake after finishing the pot of tea, it was very reminiscent of a cocaine bump. And it certainly worked well for motivating me to get busy.
But something I learned was my endurance went to shit on the caffeine. I was super impatient and wanting to do everything as fast as possible, while doing fundamentally slow long-haul heavy-mode operations. It turned out I got less done with the caffeine than without. I'd quickly burn myself out inadvertently trying to move everything faster than they were ever going to move with just my manpower. It was like the stimulant tricked me into operating deep in the realm of diminishing returns where I'm putting in 200% effort for 10% faster movement, while making myself frustrated with how long it's taking.
Now I don't think caffeine is particularly useful for anything physical that doesn't resemble a sprint, at least not for me. The psychological effects just increase the likelihood of burnout by mistreating an endurance task as a sprint.
Caffeine is performance-enhancing, raises metabolism (temporarily), and suppresses hunger.
Unfortunately, it's readily-apparent that you can never outrun your fork, so forget about "burning calories" through cardio. The goal of fitness to lose weight ought to be weightlifting to gain as much muscle mass as possible to raise one's BMR. Passive metabolism is about the only way to do it without enrolling in BUD/S. In general, gymrattery and endless treadmill running are wasted effort.
I believe this is the paper: https://jissn.biomedcentral.com/track/pdf/10.1186/s12970-020...
Seems as though we're talking about MFO (maximal fat oxidization) of 10.7% in the morning and 29% in the afternoon. Interestingly you see an increase in VO2max as well - which I believe is essentially blood oxygen.
A few things I'll point out though:
1. This is just 15 men, aged 32 +/- 7 years. Doesn't quite seem like enough people to definitively draw a conclusion.
2. They are described as 'caffeine-naĂŻve' (which I assume means they do not normally consume caffeine) - so it's unclear if this effect would be the same to somebody who already regularly drinks caffeine.
This from the study was very interesting to me:
> In athletes, it is known that endurance performance is poorer early in the morning and late at night compared with the afternoon [6], and that MFO and Fatmax are higher in the afternoon compared to the morning whether in non-athlete male students [7], in untrained normal-weight and obese individuals [8], or in endurance-trained athletes [9]. The difference has been explained by the higher body temperature, the enhanced neural activation and contractile properties of the skeletal muscle, and the higher plasma catecholamine concentrations found in response to exercise in the afternoon compared to the morning and evening [10, 11].
So it seems like regardless of if you had caffeine or not, it is better to work out in the afternoon vs. in the morning
We've known that caffeine increases aerobic capacity for half a century now. I don't see what new information this study is bringing to the table. If you take caffeine and your aerobic capacity increases, then you will either do more work, or perform at a lower percentage of your lactate threshold. In both cases, you metabolize more fat.
I no longer give much attention to nutrition or sports performance studies that test a handful of people for a few weeks. It's simply not enough people, not a long enough study, and probably not controlled enough. My guess is that there are or will be (a) study(ies) with pretty much the opposite outcome.
Years ago "studies showed" that caffeine had an anabolic effect that aided muscle growth. Now it seems that the opposite is "thought" to be true. [https://pubmed.ncbi.nlm.nih.gov/28177708/]
"15 caffeine-naive men" mean age 32 years.
Now we know why the N is so low. /s
From the study:
> This began with the same warm-up protocol, followed by increments of 50 W every minute until self-reported exhaustion
Am I wrong to think that this is simply "caffeine gives you energy to push yourself harder"? They controlled calorie intake, so simple CICO would suggest a longer exercise period needs to dig into fat reserves.
Based on my personal anecdote, drinking caffeine before athletic activities gives me the energy to more consistently work at the edge of my physical limits. When I'm sleepy, I just don't care to push myself as hard.
Regardless of this study's merits this makes some intuitive sense, since caffeine is a stimulant and a moderately performance enhancing drug. In my marathon training I consume caffeinated food as a quick "pick me up" after the first 90 minutes or so of exertion.
If you are able to run faster... well guess what... you'll also consume more calories!
The article title is misleading since the participants didn't actually drink coffee. I know, they said they ingested caffeine 'equivalent to', but it's a little misleading. There are other compounds in coffee which could increase or decrease the effects of just caffeine so it's best to not just assume it would be the same.
>15 men participated in the study
This is no where near the number of participants that would be needed to make such a broad claim
Alright, caffiene = vasoconstriction and exercise means high bpm.
Wouldn't this be a recipe for cardiac arrest?
[1] https://care.diabetesjournals.org/content/25/2/364
In [1], it is shown that caffeine decreases insulin sensitivity in cells. E.g., muscle cells use less insulin.
[2] https://academic.oup.com/endo/article/142/6/2702/2989741
In [2], it is shown that insulin inhibits mitochondrial oxidation of fatty acids.
These two findings support the finding in OP - if muscle cells use less insulin due to higher caffeine levels, they use more fatty acids oxidation.
Follow up question. Does intense exercise metabolize caffeine faster?
I usually can’t sleep if I have caffeine after 2pm but if I drink it in the evening but before a big workout I don’t notice any trouble sleeping.
I’ve always avoided caffeine before exercise because I’ve worried about overexerting myself and getting an injury from going all out. I wonder if there’s research on this factor?
This has been known for a long time and it's fairly well studied. I suppose the more interesting part for them was studying the daily variation in fat burning.
Be interested to see a percentage increase in fat burning (I.e. is it worth nailing a coffee or not if you are a big fat coder looking to shift a few pounds)
But coffee induces stomach acid reflux, which is definitely not what you want during exercise, so catch-22 here.
If my calculations are correct taking a strong cup of coffee (very strong actually), will burn 6 grams more fat per sustained hour of training.
And still we don't know if total energy output was the same, because coffee can be a stimulant so may drive you to work harder.
Kind of old news at this point right? It’s been touted as a “life hack” for at least a decade. I remember reading about this in the four hour body book. That was published in 2010. It was also based on prior studies.
If you are old and/or have a heart condition, you probably don't want to consume a lot of caffeine before working out.
Not having a heart attack is a lot healthier than fat loss, just saying.
caffeine, aspirin, and ephedra - while ephedra is banned, this combo has been long known for fat burning properties. it is unsuprising that strong coffee also works.
If I drink a full cup of good coffee before exercise I'll likely die of heart attack. My heart is starting to literally ache after I get 3 normal gulps of coffee and wait for 15 minutes.
Other anti-oxidizing drinks like green tea do help a lot though.
It really depends on the person. I was a former coffee addict and even though I mostly have quit coffee for full 10 years now I still can't get back to regularly consuming it. It's either half a cup once two weeks or a very shitty 2-3 days after.
This has been known for years, if not decades. I fail to see it as "news".
I haven't read this study, but I read about this from other studies 20 years ago.
There was not a caffeine without exercise arm. Clearly sponsored by Big Exercise.
it is of course good to get confirmation that taking a stimulant that is also a diuretic increases fat-burning - as I believe most people would suspect - but I don't think that confirmation is headline level good.
> A total of 15 men (mean age, 32) participated in the research
A sample size of 15. Seriously?
Is this really a eureka moment? I mean this has been pretty obvious.
If they approached me, I would have been a happy 16th participant.
Prisoners have known this for decades!
Or can give you a heart attack no?
anti depressants also makes you quite sensitive to caffeine
... in mice.