You Train Systems, Not Muscles Only
“What muscles am I working in this exercise,” the new client asked. “Leg press works primarily the quadriceps (front of thigh), with help from the gluteus maximus (buttocks),” I replied. This is a common exchange, especially with someone new to weight training. I then go on to add, “We train kinetic systems, not muscles only.” By kinetic system, I mean the following:
- the joint or joints doing the moving
- the muscles that do the work of shortening and lengthening to accomplish to movement
- the muscles that stabilize the body parts involved
- the tendons connecting muscles to bones
- the ligaments that hold the joints together
- the nerves and blood vessels supplying the system
- also the heart, lungs, brain and spinal chord
The weakest part of any system must be trained first. A good example is a leg curl for the hamstrings (back of thigh). The weakest part of this exercise is the last 20-degrees of flexion, when the knee is fully bent. I start all new clients on minimum resistance to be sure they work through the full range of motion. Only count the repetitions where you reach full flexion.
Injuries can also create a weak link in a system. I recently had a client who had shoulder surgery for rotator cuff repair. He recovered range of motion in physical therapy. Still, the affected shoulder was considerably weaker. We trained the weaker shoulder first by selecting a weight appropriate for it. I also had him lift a heavier weight with both arms and lower it with the weaker side. It should become as strong as the other fairly quickly.
How Hard Are You Working in the Weight Room?
In the last couple of years, I’ve come up with a scheme for measuring the level of fatigue achieved during weight training. I call it, “Four Degrees of Fatigue.” The American College of Sports Medicine’s Guidelines for Exercise Testing and Prescription (Guidelines) is the closest thing my profession has to a standards of practice. It recommends 2 to 4 sets, of 8 to 12 exercises, training all major muscle groups, working to the point that you can’t perform another rep in good form, somewhere between 8 and 12 repetitions (reps; 10 to 15 for novices and seniors). This assumes a gradual progression from where you are when you begin. If you’ve never been in a weight room in your life or it’s been a while, you’ll need to start low and go slow. This is where the Four Degrees of Fatigue comes in.
Zero Degrees of Fatigue: The weight or resistance is so light, that, even after 12 to 15 reps, it hasn’t gotten any harder. You think, “I could do this all day.” It’s useful for learning to perform the exercise, but there’s little training effect, if any. Feel free to add more resistance next set or workout, if you can do so without sacrificing form, technique and/or range of motion.
First Degree Fatigue: The resistance is sufficient to give you the sense of some fatigue. Repetition six is harder than one and number 10 is harder yet. Still, you’re able to get to 12 or 15 reps without feeling the urge to stop. This is sufficient training effect for novices and those who haven’t trained in months. It’s fine for your first 8 to 10 workouts.
Second Degree Fatigue: Now you’re starting to train significantly harder. At this point you’re using a resistance great enough to create considerable fatigue somewhere between 8—12 or 10—15 reps. As you do the exercise it gets harder fairly quickly until your think, “I could do another rep, but I really don’t want to.” After your eighth to tenth workout, begin working toward this level of fatigue.
Third Degree Fatigue: This is the level of fatigue referenced earlier in the Guidelines. The muscles become so fatigued, they simply fail. They may not fail completely, but you’re unable to do any more reps in good form, through a full range of motion. Avoid the temptation to jerk or throw the weight. That’s an injury waiting to happen.
In both second- and third degree fatigue are giving the system more work than it’s fully able to do. The system is then forced to adapt to the greater demand through a series of physiological processes. With some regularity you want to impose demands on all your kinetic systems to increase muscular strength and endurance. Select a weight that will allow you to reach the desired level of fatigue within 8 to 12 reps (10 to 15 for novices and seniors).
I should say something about sets. A set consists of all the repetitions of each exercise, performed one after another, without resting. If you’re a novice or in frail condition, you can make good progress with one set, provided you work hard and regularly. After 8—10 workouts, it’s okay to add a second set. “How many sets should I do?” is a common question. Research supports that, two sets are better than one; three sets are better than two; four sets are better than three; five sets are no better than three. If you’re an athlete, training for large gains in strength and size, go for more sets. If you’re training for general health, including weight loss and functionality, two sets are plenty.
There is no substitute for weight training. The benefits are many and the risks are few. If you’re new to it, get some expert instruction. Train consistently, two to three days a week, on non-consecutive days. Start low and go slow, while making progress and you’ll get to where you want to be. As always, if I can be of any help with this or anything else, please contact me at the below.
David Wheeler, MA, MS is Wellness & Health Recovery Coordinator at Premier Health & Fitness Center. He is an American College of Sports Medicine Certified Exercise Physiologist. David provides fitness training and health coaching for those contending with health challenges and for healthy adults who want to stay that way. He can be reached at firstname.lastname@example.org or 850-431-4835.