As an exercise physiologist, I don’t want to be one of those “165-lb weaklings, who have never lifted a weight in their lives, telling you not to do full squats.” (This was a description I heard in a conversation with a former strength coach 1987 when I was working as director of fitness at a gym in Pittsburgh. He asked me about my background, and, when I told him I had a Master’s degree in Exercise Physiology, he looked at me and said, “You’re not like the rest of them.” I take that as a compliment still today.) More recently, though, I have also not wanted to be the fitness professional who throws around a lot of science-sounding terms but has little understanding of the physiological principles of exercise.
I enjoyed an article by Joe Giandonato and Josh Bryant1 (“Maximal Strength Training for Muscle Mass”) that reminded me of that conversation from over 30 years ago. It also underscored what I have be trying teach my students—that specificity is a core principle of adaptation to physical exercise.
Exercise is largely compartmentalized. It is somewhat of a continuum, of course, but, as soon as one move from the box of specificity, one begins to see diminishing gains. The compartments are easy. We begin with health-related components (cardiorespiratory endurance, muscle endurance, muscle strength, flexibility, and body composition) and neuromotor skill-related components (speed, power, agility, balance, coordination, and reaction time). Each might lend itself to the development of the next, but, make no mistake, they are distinct. Muscle endurance is not cardiorespiratory endurance, nor is it muscle strength. The activities we perform in the exercise session must be distinctly goal-oriented. Most exercise is not inherently ineffective; it just need to be correctly matched with the desired outcome.
As I taught my Physiology of Exercise class about the Fick Equation the other day, it occurred to me that herein lies a key to explaining the idea of specificity of training. The Fick Equation stated that oxygen consumption (VO2) is the product of heart rate, stroke volume (SV), and arterio-venous oxygen difference (a-vO2diff). As VO2 is the measure of cardiorespiratory endurance, it is clear that to increase cardiorespiratory endurance one has to improve these variables. Specifically, cardiorespiratory exercise increase SV (the capacity to eject blood from the heart with each beat) and a-vO2diff (the amount of oxygen that can be removed from the blood and used by the tissue). It is widely accepted that individual differences in VO2max are due to individual differences in SV, and differences resulting from training are the result of increases in both SV and a-vO2diff. These changes do not occur with any significance as a result of muscle endurance training or strength training (though one could contend that muscle endurance may have some nominal effect on a-vO2diff—though not enough to significantly effect on VO2).
Strength is a measure of maximal force output. Thus, strength training requires near maximal efforts to yield gains in strength. Strength can develop from progressive overloading at submaximal loads—i.e., over time the lifter will lift more weight—but the effect will be limited. Strength has neurological components (e.g., the recruitment of high-threshold motor units, motor unit synchronization, rate coding, etc.—to use some heavy physiological terms), as well as muscle hypertrophy. While the cross-sectional size of muscle is highly correlated with strength, this alone is not indicative of greater overall maximal strength. Herein, terms like sarcoplasmic hypertrophy v. myofibrillar hypertrophy come into play. The former involves the increase volume of the muscle with a lesser degree of change in the muscle proteins (myofibrils, e.g., actin and myosin). Maximal strength training will have the greatest effect on the latter, but can grow muscle with both types of hypertrophy.
Body composition spans the spectrum of cardiorespiratory to strength. It refers, simply to the relative proportions of fat and lean tissue in the body. One can affect body compositions (measured as percent body fat or %BF) by decreasing fat mass, increasing muscle mass, or both. Cardiorespiratory exercise favors fat loss. Strength training favors muscle mass.
Flexibility is sort of the odd one. It is not on the continuum, but is affected by and affects the other components. An appropriate stretching, as well as exercising through a full range of motion is, nevertheless, important.
Neuromotor skill-related training is important and distinct from cardio and strength training. This is often hard to grasp because cardio and strength require some level of neuromotor skill and, in turn, offer some adaptation in these areas, but…. These are clearly skill-related. Thus, their inclusion in the training session should be considered a technique training rather than strength- or cardiorespiratory-specific training. In other words, the effects are neurological and will not affect SV, a-vO2diff, sarcoplasmic hypertrophy, and/or myofibrillar hypertrophy.
I would summarize that for exercise to be “effective” it has to meet the principle of specificity (in addition to that of overload and progression). Cardiorespiratory exercise is that which affects SV and a-vO2diff—low-to-moderate intensity steady-state (LISS/MISS), high-intensity steady-state (HISS), long, slow-distance (LSD), tempo/Fartlek, interval training (e.g., HIIT), etc.). As we move toward muscle endurance training, we can expect some adaptation in a-vO2diff and some degree of sarcoplasmic hypertrophy and fat loss. Thus, high-intensity interval resistance training (HIIRT) and high-intensity resistance training (HIRT)—e.g. circuit training and burst or “Tabata” style training with body weight and/or light weights—are more effective for body composition training, with the latter being most effective for (sarcoplasmic) hypertrophy. Strength training has to push the limits of overload and intensity. (“Do you think balancing on a Bosu or doing a random CrossFit death circuit of the day is going to get you vastly stronger? If so, then, think again.”– Joe Giandonato and Josh Bryant1) So, choose your exercise wisely. Some of the trendy exercise programs look cool—and may be more or less effective—but know what effects it will generate and consider how it will work for you toward achieving your goals.
Be your best today; be better tomorrow.
Carpe momento!
https://www.t-nation.com/workouts/maximal-strength-training-for-muscle-mass?fbclid=IwAR0CT9bHjREx5NwSKXZOCoG2lvCbzDEf_0G9LHZ6boRvLy1LQ2w4DbTvZ2k#.XbyfrxzLo-c.facebook