An article in the New York Times earlier this week addressed one of the topics Nita and I encounter frequently:
“Lifting heavy weights makes you big and bulky — or at least that’s the conventional wisdom. It’s the reason many women (and some men) who want slim and “toned” physiques opt for lighter weights, lifted more times. But the notion is not supported by science.”
People who train for “tone” rarely make much progress a “toned” physique because lifting lighter weights for more repetitions does not improve muscle tone as much as it improves mitochondria tone.
Mitochondria are the energy factories within cells. When a person lifts light weights with higher reps, a signal is sent to enhance the mitochondria rather than enhance the muscle tissue.
This effect is most pronounced in cardio vascular endurance training as noted in this review of the peer review literature:
“Prolonged endurance training elicits a variety of metabolic and morphological changes, including mitochondrial biogenesis, fast-to-slow fibre-type transformation and substrate metabolism.”
On the flip side, “heavy resistance exercise stimulates synthesis of contractile proteins responsible for muscle hypertrophy.”
Heavier weights send a signal to the body saying, “build more muscle so we can lift heavier weights” and thus increase muscle tone. The building of the muscle to increase muscle tone, known hypertrophy, burns as many calories, if not more, than the actual weight lifting.
Lighter weights send a signal that says, “enhance the mitochondria so we can move this weight more times.”
Even if a person is doing lower reps, lighter weights may not deliver much results.
This study found that “women may not self-select a relative intensity sufficient to stimulate meaningful improvements in muscular hypertrophy or strength.“
(Men will also not lift heavy enough or hard enough.)
Without hypertrophy, there is no improvement in muscle tone.
If you want to increase actual muscle tone and get the fat burning effects of weight training, lift a weight that is heavy enough you can only perform eight repetitions. This sends the signal to increase muscle tone, not mitochondria tone.
No one should ever fear building too much muscle by accident. It took Nita and I years of intense, deliberate training and precision eating to build as much muscle as we have.
In all our years in gyms and helping people get in better shape, Nita and I have never heard a person say, “I have too much muscle and need to gain some fat.”
To get a toned physique, train to build muscle, not mitochondria.
|
|
|
