Are You Actually Getting Stronger?
If you have been following us over the last couple of years, you may have noticed that we are big proponents of strength training as an essential pillar of physical health and fitness.
This is because strength training is one of the few known approaches proven to reduce injury risk and improve chronic pain conditions.
On top of that, strength training improves our blood pressure and metabolism and helps our bodies to store glucose for energy in a way that doesn’t involve converting it to fat.
It makes both daily and high level tasks easier to perform.
It vastly improves bone density and reduces falls, frailty, and physical dependence in older adults.
Most amazingly, it reduces “all-cause mortality,” or the chance of death by any cause. Meaning people who strength train live longer.
Plus, it never hurts to look a lot better in the mirror.
But sadly, despite all of these amazing no-brainer benefits, only 23% of individuals participate in some sort of strength training with only 16% reporting that they train more than once per week (according to a recent study in the British Journal of Sports Medicine).
This is especially alarming as it has been found that humans lose about 3-8% of muscle mass per decade after the age of 30.
This then begs the question: if daily life isn’t enough of a stimulus to retain muscle mass and strength over our lifetimes, then what does it take to build these attributes?
To answer this question, we must first define what “strength” actually means. The American College of Sports Medicine (ACSM) defines muscle strength as “the ability of a muscle or muscle group to exert a MAXIMAL external force.”
The key word here is “maximal.” Strength comes into play at the very limits of our force output capabilities.
In order to build this attribute, therefore, we must train at intensities that are near our maximal force output capabilities. Specifically, the ACSM recommends training with weights at a minimum of two times per week, starting around 60-70% of one’s 1 Rep Maximum (1RM) for 1-3 sets of 8-12 reps for beginners and then progressing to weights that are 80-100% of one’s 1RM for 2-6 sets of 1-8 reps for more advanced individuals. Furthermore, once the weights start to get closer to one’s 1RM and the total attainable reps are less, it is recommended to take longer breaks of 2-3 minutes or even longer in order to allow one’s energy stores to replenish enough to be able to give a full effort on subsequent sets.
This is precisely where many individuals miss the mark; they make the mistake of thinking they are doing enough to build or maintain strength, when in reality they are not doing nearly enough weight in relation to their true 1RM.
One relatively obvious but extremely common trap that people fall into is believing that, since they are on their feet a lot throughout the day and have active jobs, they are doing enough for their muscles and don’t need to strength train. In the vast majority of these cases, the forces experienced throughout the day are extremely submaximal and don’t come close to the percentages recommended above which approach one’s 1RM. Even for jobs that require heavy furniture lifting, for example, the weights, movements, reps, and rest periods are generally too variable to be able to facilitate strength adaptations.
Another common mistake is for endurance athletes, such as runners and skiers, relying on their aerobic training alone to preserve muscle strength. The reality is that the acts of running, skiing, and even biking are accumulations of extremely submaximal movements (for most individuals) and taxes our “fuel tank” as opposed to our ability to produce and withstand large forces. In fact, a study comparing monozygous (genetically equivalent) twins, one sedentary and the other a dedicated runner for 30 years, found that the runner scored higher on cardiovascular metrics but notably worse than the sedentary twin in muscle size, strength, and fast twitch fibers.
The final scenario is arguably the most challenging for people to navigate, as it looks and feels the most like strength training. High Intensity Interval Training (HIIT) and/or circuit training is justifiably all the rave right now, because it is challenging, efficient, effective, and often social. It is a great form of exercise because it frequently combines lots of styles into one. In the case of building strength, however, the fast pacing and short rest breaks common with HIIT can come at the expense of building strength even when weights are involved. The high repetitions at lower 1RM percentages characteristic of most HIIT and circuit programs tend to favor endurance adaptations over strength, which is compounded by the relatively short rest breaks between sets. This taxes one’s cardiovascular endurance and muscular “fuel efficiency” but takes away from one’s ability to exert maximal or near-maximal force over the course of several sets. When performing a lot of HIIT training it is important leave some time for strength training.
The biggest theme to take away is that if we aren’t building strength, we’re losing it. Running, performing HIIT training, and being generally active are fantastic habits to be encouraged to improve health, but this does not preclude one from needing a strength training routine as well. Muscular strength and muscular endurance are two separate attributes and training one is rarely enough to address the other. By eschewing purposeful heavy strength training, we run the risk of injury and future frailty.
Dr. Brooks Kenderdine
PT, DPT, CSCS, USAW-1
Co-Owner | The PATH Rehab & Performance
