Some highlights from my twitter between January and April, with additional commentary. I tend to tweet about recent scientific findings and other stuff I find interesting.
Do raspberries stunt muscle growth?
Tweet: “I’m a sucker for raspberries and sometimes eat them by the pound as a treat with cinnamon or cacao. Raspberry ketones may have some interesting effects: ‘Anti-obese action of raspberry ketone’. But this study makes me think twice, since it appears raspberry ketones have anti-androgenic effects. Nothing conclusive in live human subjects though.”
Comment: “Anti-androgenic effects” means that raspberry ketones (RK) block androgenic receptors, which should have negative implications for muscle growth. Since I eat a lot of raspberries, I decided to look into this.
In the discussion of the full text version of the study it was extrapolated, from rodent and cell culture studies, that the anti-androgenic effects of RK translates to an intake of ~10 mg/kg body weight, or 800 mg for the average male. Considering raspberries by themselves contain about 2-3 mg RK per 100 g dry weight, it would take about 30-40 kg/70-90 lbs of raspberries per day to reach those levels.
Suffice to say, there’s no need cut down on your raspberry intake. However, where these findings might be relevant is in the context of RK supplements, which provide anywhere between 100 mg and 500 mg (!) of RK per capsule.
The cortisol paradox
Tweet: “I have a brutal cold. Ever wondered why symptoms are always worse in the evening (runny nose, sneezing etc)? It’s due to cortisol. Cortisol peaks in the morning, which has an anti-inflammatory effect. As cortisol goes down in the evening, the inflammatory response goes up – your immune system can ‘run wild’ again = runny nose, sneezing etc.”
Comment: Cortisol gets a bad rep, but much points towards acute elevations being beneficial, as the above example shows, and not detrimental. A low morning peak in cortisol is why some people feel sluggish after waking and short term effects of cortisol administration, via dexemathasone, elevates mood, increases leptin and provides performance enhancing effects (glucocorticoids such as prednisone and dexamethasone are on the World Anti Doping Agency’s list of banned substances). The key word here is short-term. Chronically elevated cortisol, by stress or medication, is a another story. All the positive effects are basically reversed (mood is depressed, leptin is decreased, etc). When this happens depends on dose, but studies usually show that these sides occur after 3-4 days of cortisol treatment.
No best time to train?
Tweet: “It’s fascinating how some of the best workouts get done under the worst conditions. Mindset plays a much larger role than people realize. I had some killer sessions after 20 hr + fasts, semi-drunk/with a scorching hangover or with barely an hour of sleep. Or like today, after having been out of commission for almost a week due to a cold.”
Comment: Well, the tweet pretty much says it all. I’ve had some crappy workouts under “ideal” conditions and some great ones under the worst possible conditions. And vice versa, of course.
Knowledge-based work and overeating
This was originally a comment on Lyle’s article. More specifically this part:
“Moving on to the other topic of the paper we get to KBW, again referring to activities such where you’re sedentary but engaged in large amount of mental activity. The paper mentions work, school, even video games and computer ‘chatting’ (you Facebook people know who you are) and other related activities as potential examples of KBW.
And, as you might expect, while similarly sedentary like sleeping, the impact of KBW on appetite and body weight regulation tend to be rather negative. The brain, unlike skeletal muscle, can’t use fat for fuel and studies have shown that intense thinking can screw blood glucose levels; this is relevant as some work shows that falling or lowered blood glucose can stimulate hunger.”
Tweet: “The study you quoted on ad lib feeding and KBW, the exercise used in that study was perceived as a stressor by the women (as shown by higher cortisol levels vs the control condition), and that’s a significant confounder. KBW is not the trigger for overeating, stress is. I don’t think this was made clear enough in the article. Is there a link between non-stressful KBW and higher calorie intakes in a similar fashion? I don’t think so. Could chatting and WOW contribute to overeating in a similar fasion? Perhaps if they are perceived as stressful events.”
Comment: My point here was that it’s impossible to say that it’s KBW per se that predisposes towards overeating, but rather the stress caused by it. It’s not likely that unstressful and leisurely KBW would have the same effects on glucose metabolism and appetite.
Juicing with aspirin?
Tweet: “NSAIDs such as aspirin and ibuprofen inhibit adaptations to resistance training when taken prior to the workout…but actually helps if taken AFTER the workout…and quite significantly so vs placebo: ‘Timing of ibuprofen use and bone mineral density adaptations to exercise training’. Maybe we’ll see people juicing up on aspirin soon”
Comment: An undesirable side-effect of NSAIDs (Non Steroidal Anti-Inflammatory Drug) is inhibition of prostanglandin synthesis, which results in impaired bone formation. Increased bone formation is one of the adaptations to weight training. Needless to say, taking NSAIDs in conjunction with weight training is something you’d want to avoid. However, animal studies have previously shown that this effect only occurs when NSAIDs are taken prior to mechanical loading. The aim with this study was to test whether this was true for humans as well.
The participants in this study were split into three groups and studied for nine months, during which they were weight training three times a week.
- IBUP/PLAC: Received 400 mg ibuprofen prior to weight training, and placebo after.
- PLAC/PLAC: Received placebo prior and after training.
- PLAC/IBUP: Received placebo prior to weight training, and 400 mg ibuprofen after.
The results showed that bone density in IBUP/PLAC decreased by 0.2%. Regular weight training was not sufficient to compensate for the negative effects of consistent ibuprofen intake.
PLAC/PLAC showed a small and predictable increase of 0.4% in bone density.
And here’s the kicker: PLAC/IBUP showed an increase of 2.1% in bone density. So post-workout ibuprofen intake basically increased bone formation by 500% compared to placebo, which is pretty crazy.
What’s the explanation here? The researchers speculate that ibuprofen may protect against, or dampen, the surge in inflammatory cytokines which occur post-workout. Inflammatory cytokines acutely inhibit bone formation, so NSAIDs could theoretically combat this by anti-inflammatory action.
However, another perspective on this, not mentioned in the paper, is that exposure to inflammotory cytokines, and other metabolic by-products such as free radical formation, is necessary for optimal training adaptation.
Regardless of the precise mechanism behind the effects of NSAIDs on bone formation, it’s safe to say that if you need to take them, do it post-workout.
Lifting weights for toning is horseshit
Tweet: “NY Times: Lifting light weights for “toning” is horseshit: The Claim: For Better Muscle Tone, Go Lighter and Repeat. That’s what I’ve been saying for years…but it’s good to see the mainstream catching on.”
Comment: I’ve never believed that women’s training routines should look much different from men’s training routines in terms of the general setup. The only thing I change is expanding the repetition interval.
I typically use a double progression model where the load is increased when x reps are performed. So for a male, I might tell them to increase the weight by 2.5% or 5 lbs when 8 reps are performed. This usually translates to 5 lbs in most movements, except deadlifts and squats, since 5 lbs is the bare minimum in terms of plates available.
For women, an increase of 5 lbs usually translates to an increase in 5% load or more, which results in a drop off of more reps. Let me give you an example.
- Male, bench press (rep range 6-8, increase at 8 reps)
- 200 x 8 to 205 x 7 (+2.5%). Loss of 1 rep, assuming strength is unchanged.
- Female, bench press (rep range 6-9, increase at 9 reps)
- 80 x 9 to 85 x 6-7 (+6.2%). Loss of 2-3 rep, assuming strength is unchanged.
I tend to stick to the 6-8 rep range for most – not all – upper body movements. If I would have used the same rep range for women, they’d sometimes hit 5 reps or less when increasing the load, which is why I expand the range. This is particularly important for dumbbell movements. For example, going from 20 lbs dumbbells to 22 lbs dumbbells would equate a 10% increase in load and the loss of 4 reps or more. In such cases, I use a 6-10 rep range.
Vegetarian diets and muscle growth
Tweet: “Vegetarian diets aren’t optimal for muscle growth: see my comment in ‘Book Review: Muscle Gaining Secrets’.
Comment: This was in response to someone who asked me about data for my claim that vegetarian diets aren’t optimal for muscle gains. I brought it up because Ferruggia advocates a vegetarian diet – or so I thought. He actually advocates a vegan diet, which is even worse. Anyway, you can see my response in comments, but the gist of it is this:
Studies have concluded that a protein intake of 2 g/kg body weight is needed to optimize muscle gains. However, these studies are based on non-vegetarian diets. Why is this important? It’s not only about total protein intake, it’s about the BCAA content of the diet. BCAAs, and particularly leucine, are the amino acids most intimately involved in controlling muscle protein synthesis. BCAA content in relation to total calorie content of different foods:
- Whey protein: 25% BCAA
- Animal protein: 17-18% BCCA
- Egg white protein: 18% BCAA
- Soy protein: 15-18% BCAA
- Cottage cheese: 10-13% BCAA
- Beans and peas: 4-5% BCAA
- Nuts: 2% BCAA.
Speaking of nuts, they’re probably the most overrated food deemed “healthy” by the mainstream. I talked about this in “Scorch through your fat loss plateau”.
As you can see, plant protein doesn’t rank very high in terms of BCAA content. It’s likely that a vegetarian diet containing 2 g/kg protein would have a much lower BCAA content than a 2 g/kg protein non-vegetarian diet. Meaning that, in order to get the same effect, you’d have to eat more total protein to reach the same BCAA content than a non-vegetarian diet. Unless you’re planning on consuming tons of soy protein (which might have adverse effects).
Now, for a ovo-lacto vegetarian with a decent base of nutritional knowledge it wouldn’t be too hard to get quality protein by adding a lot of cottage cheese, egg protein and even whey protein. The real issue as I see it is mainly with vegans and some vegetarians that don’t have a clue about what sources to get quality protein from.
Protein trumps fat for satiety
Tweet: Protein trumps fat for satiety: ‘Postprandial ghrelin and PYY responses of male subjects on low carbohydrate meals to varied balancing proportions of proteins and fats’
Comment: Nothing new here, just a firm reminder about why I advocate high-protein diets for maintaining low body fat in the long term. It’s not that I believe high protein intakes beyond a certain point leads to improved muscle growth, but rather due to the effects on satiety and metabolism (via TEF). Read more here: “Maintaining low body fat”.
P.S. I fixed the “Like”-button below, so now it shows you liked the specific post/article and not just my site.