Mark Sisson has become a very popular paleo promoter and I like a lot of what he has to say. His book is pretty good and I hate him for all the hair he has on his head. I wish it were true that going paleo was good for hair re-growth but its not.
As good as his nutritional info is, I came across a blog of his that has some inaccurate exercise information. Since he is so popular (WAY more popular than I am), and can influence many, I thought it was necessary to address these errs as they are both misleading and potentially dangerous.
I am not saying that Mark purposefully puts forth exercise recommendations that he knows are harmful. Nor am I suggesting that he doesn't know what he's talking about. So don't anyone think this is a Mark Sisson bashing blog. It is not.
In the blog Mark says:
...the idea that muscle significantly boosts resting metabolic rate is pretty much nonsense.
Well, it's actually not nonsense. I suppose we have to define "significantly." It seems to me that any increase in resting metabolic rate above 100 calories a day is significant.
Here is an article by Dr. Wayne Westcott that I think is a very good explanation of why and how weight lifting does indeed increase RMR significantly.
From the article:
However, if the strength-training program adds 3 pounds of muscle tissue for a total of 65 pounds of skeletal muscle, and if each pound of trained muscle now uses 7.2 calories per day at rest (a 1.5 calorie increase), then the new contribution to his resting metabolism is about 468 calories (65 pounds of muscle x 7.2 calories per pound = 468 calories).
This represents about 115 additional calories expended each day at rest (353 calories to 468 calories = 115 calories), which increases his resting metabolic rate by approximately 7 % (1,600 calories per day x 7 % = 112 more calories). This metabolic increase is consistent with the research findings by both Campbell, et al., and Pratley, et al.
The key here is not just the added muscle tissue, but the totality of the trained muscle. So in my opinion, it is somewhat misleading to say that an increased RMR attained via resistance training is nonsense.
Even though Mark correctly downplays the role of aerobic activity for fat loss, suggesting that resistance training does nada to help increase fat loss might lead people to believe they do indeed need to add aerobics into the fray to burn more calories and this is almost always a fat loss faux pas.
The other err Mark puts forth and the one I think is the worst offender is the following:
How does one get increased muscle mass? Why, by lifting heavy things.
Well, yes and no. It is one way - so long as you lift heavy things to complete muscle fatigue or "muscular success" as we call it at Serious Strength - or darn near it. But it is a dangerous way to be honest.
Dr. Ralph Carpinelli wrote a very good paper on why the heavier is better idea is nonsense. This does not mean that very light weights will work either. But to suggest to people that you must lift heavy objects to build muscle is, in my opinion, a tad on the side of "uh-uh."
From the paper:
The size principle states that motor units are recruited in an orderly manner from the smaller (lower threshold) to the larger (higher threshold) motor units, and that the recruitment is dependent on the effort of the activity. Greater recruitment produces higher muscular force. However, the pervasive faulty assumption that maximal or near maximal force (very heavy resistance) is required for recruitment of the higher-threshold motor units and optimal strength gains is not supported by the size principle, motor unit activation studies, or resistance training studies. This flawed premise has resulted in the unsubstantiated heavier-is-better recommendation for resistance training. [ J Exerc Sci Fit • Vol 6 • No 2 • 67–86 • 2008]
What this means is, you don't need to lift heavy things to gain added muscle and strength. And since you don't, you shouldn't as the heavier the weight is, the closer you come to injury.
My suggestion is to choose a weight or resistance that allows for at least 50-60 seconds of effort before muscular success occurs. This ensures that the load is not too heavy. But your behavior matters too of course. Yanking, thrusting or heaving into a light weight can also cause harm. Slow and steady wins the muscle!
As the Hippocratic oath states: "Do no harm." This is a good oath. Don't endanger yourself by lifting very heavy things and don't pound your joints to dust in the attempt to burn the extra calories that resistance training supposedly doesn't provide.
As Mark would undoubtedly agree, eat fatty, wild caught proteins and some locally grown plant matter only. Drink fresh water.
But lift moderately heavy weights slowly and infrequently. Forget calories entirely but know that your weight training is doing you great metabolic good.
And Mark, keep up the great work!