April 2019

How Much Do You Have to Lift to Get Strong…or Big?

A study that evaluated the required volume of weight lifting exercises necessary to effect muscle strength and size (hypertrophy) made all the news at the end of 2018. In what might be considered a large study of this type, 45 healthy, young males who were experienced with regular weight training were divided into three groups: low- (1-Set), moderate-(3-Set, and high-volume (5-Set). They all did the same lifts and same percentage of loading 3/wk for 8 weeks.

Ultrasound measurements of muscle size were done for biceps, triceps, and quadriceps. Strength tests were only done for squats and bench presses. Only bench press endurance was used as a gage of muscle endurance.

Astoundingly, the results showed that 1-Set of 8-12 repetitions done 3 x a week was virtually as good as doing 3-Sets of an exercise thrice weekly.

Too, muscle endurance was similarly improved regardless of volume. Furthermore, biceps size was improved with multiple sets but triceps size was hardly different between groups. Mid- and lateral-thigh muscle sizes were improved more in the 5-Set group but there was not much difference between the 1-Set and 3-Set groups when it came to leg muscle size changes.

However, what did not get mentioned in the news reports, after touting the value of a 13-minute workout vs a 39- and 65-minute workouts, was that the dropout rate for the study underpowered the statistical results. That, and the fact that some of the subjects were unable to complete some of the strength tests.

Thus, while the overall message was positive – that three 13-minute sessions/wk of resistance training is sufficient to see strength and hypertrophy gains – you might want to do a little more to ensure benefits.                 

MSSE Jan. 2019

Female Bone Density Impacted by Muscle Mass

Bone mineral density (BMD) is a concern for aging women and for certain athletes who tend to keep body weight low by under-eating or over-exercising. Most of the literature on osteoporosis suggests that what we do up to age 30 or so lays the foundation for how much BMD we enter middle age with.

A large multi-year study followed over 1800 Iowan families over a 15-year period. Starting at age 5, up through 17, DXA scans were performed at ages 5, 8, 11, 13, 15 and 17 to determine BMD. Also, physical activity records – reported and measured with accelerometers – were assessed each testing age to gage how much moderate and vigorous activity and sedentary behavior each kid did. Finally, leg muscle mass was measured by DXA.

The results were noteworthy for two reasons. First, those who had maintained higher levels of physical activity from childhood into adolescence had higher whole-body and regional BMD. Significantly, those with more leg muscle tended to have better proximal femur bone quality; in fact, this was more notable among females than males.

This suggested that muscle loading, despite lower overall muscle mass, was more important for young females to build more bone than it was for males.

Activities with “strong (de)accelerations of the body or with maximal-force muscle contractions” have already been shown to be superior for “augment[ing] muscle mass and bond strength.” This lead to the other conclusion that muscle was a mediator for BMD and should be considered not just a mechanical factor but an endocrine organ capable of exerting independent influence on young kids’ bones.                           

MSSE Jan. 2019

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