Wednesday, August 30, 2017

The Role of Our Glutes

We all know we need to, "strengthen our glutes," but have we stopped to think about why we need to do that other than to look great in a tight pair of jeans?

The answer is because our glutes play a very important role during gait. When we heal strike, ground forces travel up through our ankle, knee and beyond. To brace for impact, our foot supinates (tilts to the outside), compressing our bones to increase its' rigidity. As we bear weight upon it, our foot pronates (tilts to the inside) to absorb the energy into the tissues of our arch. When this happens, our tibia (shin) is forced into internal rotation, causing our femur to internally rotate at an even faster rate. The discrepancy between the rates of tibial and femoral internal rotation stresses the medial side of our knee and our ACL (Anterior Crucial Ligament).

This is where our glutes come in! Their role is to decelerate rotation of our femur during gait to protect the integrity of our knee. As such, we want to keep our glutes strong. One way to do this is to make sure we don't stand in a pronated position (feet sinking into the arches). Another way is to practice, "glute dominance" when doing bend-and-lift movements. This can be accomplished by initiating the movements with a hip-hinge. For more information on how to properly activate our glutes during a body squat, please see my post, "Mechanics of the Body Squat."

Our glutes protect the integrity of our knee

Comana, Fabio. "Lower Extremity Movement Mechanics." 2017 IDEA Health & Fitness Association.
Comana, Fabio. "Functional Programming for Stability-Mobility and Movement." ACE Personal Trainer Manual, American Council on Exercise, 2010.

Tuesday, August 29, 2017

All About Power

Let's face it, most of us don't have the time or the energy to commit to long cardio workouts. Hence the growing popularity of the time-efficient 30-minute sessions. But, how can we ensure that we get the most bang for our buck in 30 minutes? Studies have shown that EPOC (Excess Post-Exercise Oxygen Consumption) is driven by intensity, not volume. Since the number of calories we burn is dependent upon the amount of oxygen we consume, let's add intensity to our short training sessions!

Intensity is achieved by training with power. To train with power, we need to target our fast-twitch muscle fibers and their anaerobic energy systems. This can be done with a carefully planned HIIT (High Intensity Interval Training) format. I say, "carefully planned" because if enough time between intervals is not allowed for the anaerobic energy systems to replenish their ATPs, the purpose of the training is defeated due to diminished power output.

So, what's an appropriate HIIT format for power training? VIIT (Variable Intensity Interval Training) is a type of HIIT protocol that combines HIIT and CV (Cardiovascular) conditioning. This type of training targets the anaerobic energy systems using 30-second all-out power efforts followed by active recovery at a comfortable but challenging intensity. To understand the benefits of this type of training, it helps to understand how the anaerobic energy systems work. During the first few seconds of an all-out effort, our muscles use their immediate energy source, ATP (Adenosine Triphosphate), which is located on the myosin heads of the contractile proteins of the muscle fibers. Energy is released when ATP is broken down to ADP (
Adenosine Diphosphate), Pi (Inorganic Phosphate) and H+ (Hydrogen Proton). As the effort continues, CP (Creatine Phosphate) is split by the enzyme, creatine kinase, and the energy released from that reaction is used to resynthesize ATP from ADP and Pi. When CP is depleted, anaerobic glycolysis takes over, breaking down glucose into pyruvate. Pyruvate converts to lactate by taking on the H+ produced during glycolysis, preventing the environment from becoming too acidic. Lactate is pushed from the muscle cells into the blood to be buffered. When we reach the point of breathlessness after our 30-second all-out effort, we know we have used our anaerobic systems because expiration of CO2 is a result of our buffering system.

So, what's the benefit of training this way? When we train anaerobically, our body oxidizes fat more rapidly, preparing for an eventual increase in its' usage. This rapidity equates to more calories being burned. Additionally, during active recovery of the anaerobic systems, we use our aerobic system to replenish ATPs. This is the only system in which fat is burned. It is comprised of the mitochondria, which encompasses the Krebs cycle, i.e. the fat-burning fireplace. Our muscle cells contain anywhere from 400-2000 mitochondria. Mitochondria have their own DNA and will adapt to VIIT by getting 35% bigger and replicating by 15-50%. More fat-burning factories and more calories burned by training consistently with power for just 30 minutes sounds pretty good to me!

Let's add intensity to our short training sessions!

Comana, Fabio. "HIIT vs. HVIT." IDEA Health & Fitness Association.
Kravitz, Len. "Metabolic Conditioning: Myths, Mysteries and Monster Workouts." 2016 IDEA Health & Fitness Association.
Kang, Jie. "Bioenergetics Primer for Exercise Science." Human Kinetics, 2008.

Saturday, August 12, 2017

Mechanics of the Body Squat

Since I started wearing my Vibram shoes and can now feel my feet on the ground, I've become aware of my natural tendency to supinate my left ankle while doing power presses in my BP 30! (Body Pump) class. This could be the culprit in my patellofemoral tracking disorder (kneecap tracking to the outside) as I would be placing more stress on the lateral muscles of my left leg. I decided to write this post in case I can help others become more aware of their own body position when doing bend and lift movements, such as the body squat.

To get into the proper body squat position, follow these steps:
  • Stand with your feet beneath your armpits;
  • Supinate and pronate your ankles until you find the neutral position of the tibia on the talus (i.e. ankle bones are level and you feel the three points of contact on the bottom of your feet - heel, first metatarsal, fifth metatarsal);
  • Hinge by driving the hips backward with a slight bend in your knees. To make sure you are hinging correctly, face a wall standing a few inches away and press your hips back without hitting your head on the wall;
  • Once you hinge, protect your low back by pulling your tailbone slightly forward, engaging your abs;
  • Allow tibial translation forward once you get past 30 degrees of hip flexion, keeping your knees in line with your 2nd and 3rd toes (it's okay if your knees go slightly past your toes);
  • Keep your torso parallel to your shins throughout the squat.

    Keep your torso parallel to your shins throughout the squat

References :
Comana, Fabio. “Lower Extremity Movement Mechanics.” 2017 IDEA Health & Fitness Association.
Comana, Fabio. “Functional Programming for Stability-Mobility and Movement.” ACE Personal Trainer Manual, American Council on Exercise, 2010.