In Strength Training, Tempo refers to the speed at which an exercise is performed. Many Strength Training movements have a Concentric (lifting), Eccentric (lowering), and Isometric (pausing) component. In a Barbell Shoulder Press, for example, the Concentric phase is the pressing of the bar overhead, while the Eccentric phase would be the lowering of the bar back to the start position. Per recognized Strength Coach Charles Poliquin (http://main.poliquingroup.com/), the Eccentric phase occurs when a muscle contracts while lengthening. Meanwhile, the Concentric phase occurs as a muscle contracts and shortened.
Tempo and Time Under Tension (TUT)
Recent studies have shown that a very deliberate Tempo might induce growth in stubborn muscles. One such study (1) reported that the leg extension exercise executed at 30% of maximum effort (a relatively light load) with a slow lifting movement (six seconds up and six seconds down) performed to fatigue produces greater increases in rates of muscle protein synthesis than the same movement performed rapidly (one second up and one second down). These results suggest that the time the muscle is under tension (also known as TUT) during exercise may be important in optimizing muscle growth.
Understanding that Time Under Tension (TUT) is directly tied to muscle protein synthesis can help a trainee build up an injured, weak, or underdeveloped muscle group, or help prevent the muscle loss that naturally occurs with aging. Using a Slow Tempo has been shown to be a viable alternative to increasing Intensity when adding more repetitions or weight is impractical.
Training with an exaggerated Tempo has been repeatedly shown to be effective in the rehabilitation of injuries. Askling et al (2) conducted one such study in which the group directly compared a protocol of conventional exercises with a protocol based on Eccentric exercises. The group found that Eccentric Training with a deliberate Tempo was very effective compared to conventional training that disregards Tempo.
Tempo Training has a lot of applications, one of which is to correct a dysfunctional firing pattern with a muscle group. For example, if your Glutes are stubborn to fire, the use of lighter weight and a deliberate Tempo can be very useful in getting them to activate.
The human body is geared for efficiency, and what tends to happen is that different muscle groups will compensate for weak or inactive synergistic muscles in given movements. Basically, your body will find the path of lease resistance in jumping, running, throwing, etc. If three of your muscles are doing work intended for four of your muscles, it’s only a matter of time until you incur an overuse injury. When one muscle group is doing a disproportionate amount of work, the condition is referred to as a Muscular Imbalance.
Here’s a visual of some common Muscular Imbalances, per Janda (3):
A very common Muscular Imbalance, as seen above, is Inhibited Glutes combined with Facilitated/overused Iliopsoas. The Psoas will be discussed at length in a future article, but the takeaway is that the Psoas becomes chronically overworked, short, and tight while the Glutes become lax and weak from disuse. Aside from robbing someone of athletic performance, this condition also sets someone up for pain and eventually injury.
If your Gluteal muscles are inhibited or inactive, an undue burden will be placed on smaller or mechanically inefficient muscle groups in the surrounding area, such as the Hip Flexors or the Psoas. As you fatigue these smaller or alternate muscle groups, the burden will then be placed on the accompanying joints. The reason there is such a strong correlation between non-contact ACL (Anterior Cruciate Ligament) injuries and Glute Inhibition is because inactive glutes force a tremendous mechanical burden onto the quadriceps and the ligaments surrounding the knees.
In a study geared toward limiting the risk factors for ACL injuries in soccer players (https://link.springer.com/article/10.1007/s00167-009-0813-1), Valgus Collapse, a poor Hamstring-to-Quadriceps Strength Ratio, and increased hip internal rotation and tibial external rotation (with or without foot pronation) were among the main risk factors cited. All three of these conditions correlate very strongly with inhibited and weak Gluteus Maximus muscles. While an ACL injury is devastating to an athlete, no one wants an injury with a 4-8 month recovery timetable.
So regardless of your fitness goal, it would be in your best interest to make sure all of your muscles are firing properly. The catch is that your bigger, stronger, well-conditioned muscles will be apt to take over during movements, particularly as the intensity level increases. This is where advanced training techniques such as alterations to Tempo can help a trainee progress or rehab a nagging injury.
Get to Know Your Body: the Gluteus Medius and the Brachialis
Two particularly stubborn muscles that deserve special consideration in regard to Tempo are the Gluteus Medius and the Brachialis. Both of these muscle groups are critical to good form and function, and might be better stimulated by Strength Training or Rehabilitation exercises done with a very deliberate Tempo.
First consider the Gluteus Medius (also referred to as the Glute Medius), which is a small, thick muscle that rotates and stabilizes the hip:
As a test, close your eyes and stand on one leg. Did you start to wobble? If so, the strength of your Gluteus Medius might not be up to par.
Here is a list of Strength Training and Rehabilitation exercises that are used to target the Gluteus Medius:
- Barbell Lateral Step-Over
- Dumbbell Single-Leg Romanian Deadlift
- Hip Abduction Machine
- Hip Adduction Machine
- Monster Band or X Band Walks
- Single-Leg Back Extension
These are all very effective exercises, if done properly. The problem is that most people tend to use incorrect muscles to complete the movements, and the result is at best ineffectiveness and time wasted. At worst, the consequence can be pain or injury. In the case of Hip-Hinge movements like the Dumbbell Single-Leg Romanian Deadlift (pictured above), the lower back most often takes the brunt of the punishment if one or more of the Gluteal muscles aren’t firing properly.
You may be wondering, “how does someone target an under-active muscle such as the Gluteus Medius if the bigger muscle groups are apt to take over?”
There is a saying within the Fitness Community, “Isolate to Integrate”. This means that if a muscle is slow to fire or stubborn the grow, the best course of action is to work the muscle in Isolation, meaning as part of a single-joint movement.
A main way to work the Gluteus Medius in Isolation is Lateral Hip Abduction. The most basic way to do this is with a Side Lying Leg Raise:
There are a number of ways in which you can tweak this movement to make it more effective, one of which is to emphasize the Eccentric/Lowering component. You can learn more about the benefits of Lateral Hip Abduction in this video.
Once you have located the Glute Medius, it may humble you to realize how weak or under-trained these muscles tend to be. Many trainees, even advanced weight-lifters and Powerlifters, will tell you their Glute Medius feels like it’s on fire after a bodyweight set of 30-40 Lying Side Leg Lifts. It’s certainly not a “macho” movement, and even when a person can squat or deadlift hundreds of pounds, the Glute Medius muscles remain woefully underdeveloped.
The Brookbush Institute, a physical therapy practice and online education forum, has an extremely comprehensive program for activating the Gluteus Medius available for free here. The trick is to train the Glute Medius muscles in isolation, and until a trainee becomes comfortable utilizing it, a very deliberate Tempo is likely in order.
Again per Charles Poliquin, while a deliberate Eccentric Tempo of four seconds or more may not induce growth in Type IIA and Type IIB muscle fibers (40 percent growth versus 10 percent growth), exaggerated Eccentric Tempos of four seconds or more still provided significant stimulus to the targeted muscle. As Poliquin notes, “Slower Tempos with lighter weights are a staple of programming when recovering from an injury to increase blood flow to the injured area, gain strength, and focus on getting the muscles to fire effectively”. (4)
Utilizing basic bodyweight movements such as Clamshells or Side Lying Leg Raises, under deliberate lifting/lowering Tempos of four or more seconds, would seem to be an excellent way to get a stubborn or inactive muscle group to fire properly.
Once you have located and gained a bit of strength in your Glute Medius muscles, it may astound you to see the gains you immediately make in muscular endurance or strength during lower-body movements. The Glute Medius is incredibly powerful in its ability to potentiate and stabilize the lower leg and in particular the Gluteus Maximus – likely the biggest, strongest muscle group in the body.
Even if you don’t have immediate athletic or physique goals, strong and functional glutes are potentially the number one way to alleviate lower back pain. Per the American Council on Exercise, “The Gluteus Maximus works to decelerate flexion of your hips to help counteract the downward pull of gravity and prevent your lumbar spine from over-rounding forward. If your Glutes are not strong enough to fully engage when your hips bend backward, your spine must round forward excessively to lower your arms to the ground”. (5, Price, J. and Bratcher, M. (2010). The BioMechanics Method Corrective Exercise Educational Program. San Diego, Calif.: The BioMechanics Press).
Forward Flexion is just one of the many roles the Glutes undertake, and inhibited or non-firing Glutes have an almost complete correlation with lower-back pain (6, McGill, S. (2002). Low Back Disorders: Evidence Based Prevention and Rehabilitation. Champaign, Ill.: Human Kinetics). So even if you’re not an active or aspiring athlete, getting your Glutes – and especially the mousy Glute Medius – to fire properly will go a long way toward preventing or resolving lower-back pain.
Another underappreciated muscle is the Brachialis, which serves as the strongest flexor of the elbow joint and comprises a sizable portion of the upper arm (https://www.kenhub.com/en/library/anatomy/brachialis-muscle):
While the Brachialis serves tremendous function within the body as the primary elbow flexor and strongest grip muscle, it also has great aesthetic value for the fitness-minded:
When seen from the side, the Brachialis adds depth to the upper arm, and separates the Biceps brachii from the Triceps. While the Brachialis provides both form and function, it can be a difficult muscle to target in training. This is another instance in which a Slow Tempo might aid a trainee with their performance or physique goals, or help someone rehab achy elbows.
The Dumbbell Hammer Curl is the most basic, effective way to train the Brachialis:
The issue is that many people already have sore elbows or forearm flexors because the Brachialis is underworked or inhibited. This is where physical therapy-style training with a Slow Tempo and an exaggerated Eccentric has great value.
As recommended in the Leg Extension study noted above, a training recommendation would be to use about 30% of a one-repetition maximum with a very deliberate Eccentric of six seconds or more to mechanical failure.
While the Dumbbell Hammer Curl has stood the test of time as an effective way to train the Brachialis, there are other exercises that effectively target the Brachialis, such as the Reverse-Grip Straight Bar Curl, Cross-Body Hammer Curl, and the Neutral-Palm Rope Curl. The key is to find an exercise that you can feel working the targeted muscle, and a modality and weight that allows you to move painlessly.
How Slow Should You Go?
Assuming you want to give Eccentric or Deliberate Tempo Training a try, the next question becomes, “How Slow Should You Go?” in order to see optimal results.
Arthur Jones, an exercise scientist behind the famed Colorado Experiment, once recommended a Strength Training Tempo with a two-second Concentric phase and a four-second Eccentric or Negative phase. The goal of the Colorado Experiment was to see how much muscle mass an individual could potentially accumulate, and Jones used a bodybuilder named Casey Viator as his lab rat. Viator reportedly gained 63 pounds of muscle mass in 28 days, and Jones used a number of high-intensity training techniques such as eight-second Eccentrics and non-existent rest periods between exercises. The results of the Colorado Experiment, which was conducted in 1973, have never been duplicated. However, Arthur Jones’ use of Nautilus machines and Eccentric/Negative Training are Strength Training modalities that continue to be heavily relied upon over 40 years later.
Burd et al (6) recommended Eccentric and Concentric Phases of six seconds each at 30% of one-repetition maximum. Charles Poliquin recommneded Eccentrics of 4-6 seconds, depending on the intensity, the movement, and the health of the trainee. Ultimately, some trial-and-error will be involved depending on the trainee and the muscle group, but Tempo guidelines including Eccentric/lowering phases of four seconds or more have been repeatedly shown to be effective in activating weak or inhibited muscles.
Dietary considerations are always a factor in muscle protein synthesis and injury recovery. Ketogenic Diets are gaining a lot of traction as being effective in promoting increased insulin sensivity, and thus muscle protein synthesis and optimal health. You can read about Ketogenic Diets and other dietary information at Dietspotlight.com.
Tempo and Time Under Tension are not the sole factors in muscle growth, but their importance is very well-established. If you are seeking to improve a lagging muscle group, expedite the healing of a muscle injury, or activate an underused muscle group, research suggests that Tempo Training is an ideal modality.
Shawn Farrell is a Diet Spotlight contributing writer. He has a B.S. in Exercise Science and has 15+ years of training experience. Concerns and questions can be forwarded to firstname.lastname@example.org.