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Research in Review: Full or Partial Back Squat- Which Activates the Muscles More?

The purpose of this study was to evaluate the muscle activation

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See how muscle activation differs (or doesn’t) between the partial and full back squat.

Journal Article:

Da Silva, J.J., Schoenfeld, B.J., Marchetti, P.N., Pecoraro, S.L., Greve, J.M., &Marchetti, P.H. (2017). Muscle activation differs between partial and full back squat exercise with external load equated. Journal of Strength and Conditioning Research, 31(6), 1688-1693.

Purpose of the Study:

The purpose of this study was to evaluate the muscle activation between partial and full back squat exercise when performed with the load equated on a relative basis.

The load made equal (equated) because there is an assumption that changes in the range of motion during the squat can affect the magnitude of the load. This is thought to affect muscle activation. In an attempt to regulate this effect, ratings of perceived exertion were also taken into consideration after each set.

Study Participants:

15 young, healthy, resistance trained men participated in the study. Subjects had no previous lower back pain, no surgery on lower extremities, and no history of injury with residual symptoms, such as pain, in the lower limbs within the last year.

Procedure or Methods:

Subjects attended 2 sessions in the laboratory separated by 1 week. During the first session, the participants were instructed on the proper squat technique. Condition 1 was the partial squat (0 to 90° of knee flexion). Condition 2 was the full squat (0 to 140° of knee flexion). All participants performed both conditions.

On the first visit to the lab, participants were to establish baseline data to be used on the second visit. The participants warmed-up for 5-minutes on a stationary cycle then performed 10 repetition maximum test of the squat at a self-selected cadence. If the 10 reps were not achieved, the participant was given a 5-minute break, and then the weight was adjusted by 4-10 kg. Participants were given standard instruction regarding exercise technique along with verbal feedback and encouragement. A 30-minute break was given, and then the procedures were repeated for the alternate condition.

On the second visit, participants returned to the lab for the actual recording of data. Again subjects warmed up with 5-minutes on a stationary bike. They then performed 1 set of 10 RM for condition 1 and condition 2 with a 30-minute rest between each condition.

Surface EMG data were collected on the gluteus maximus, vastus lateralis, vastus medialis, rectus femoris, biceps femoris, semitendinosus, erector spinae, and the soleus. Signals collected during all conditions were normalized to maximum voluntary isometric contraction (MVIC).

Results:

The surface EMG activity was significantly greater in the partial compared to the full squat for the gluteus maximus, biceps femoris, erector spinae, and soleus. No significant differences were found in any other of the muscles studied.

Discussion:

The main finding of this study was that both the partial and full squat demonstrated a similar overall level of muscle activation of the rectus femoris, but a higher level of activation in the gluteus maximus, biceps femoris, and erector spinae was found in the partial squat.

The higher activation of the gluteus maximus is likely due to it being a single joint muscle positioned at the hip where there is a longer lever arm during the partial squat. The reduced activity in the full squat may be due to the gluteus maximus not being used as much at greater knee flexion angles. Also, at the greater depth, the gluteus maximus is not needed as much to stabilize the pelvis. In some cases, the gluteus maximus may have to relax to permit greater hip flexion angles to be achieved.

The higher activation of the biceps femoris in the partial squat may be explained by it acting as a joint stabilizer at the knee and a prime mover at the hip for extension.

The increase in rectus femoris activation in the full squat is due to the greater moment across the knee joint since it connects to the tibia via the patella tendon. Therefore, as knee flexion increases, activation of that muscle will also increase. The vastus medialis demonstrated the same activation in both conditions and the vastus lateralis activated only slightly more in the partial squat. However, the increased activation in the vastus lateralis was not significant.

The authors believe that the erector spinae activated more in the partial squat in an attempt to control forward trunk motion to control the center of pressure through the range of motion.

Take away for NASM-CPTs:

This study has several implications for the NASM-CPT. First, this is further evidence that a partial range of motion squat is better than no squat. A full squat requires optimal flexibility and range of motion from the ankle, knee, and hip, as well as, total body coordination and strength. While a full range of motion should be the desired end-goal, clients that don’t have the flexibility or strength to achieve it will benefit from the partial squat. Second, a partial squat should also be considered if a client can’t obtain a full squat due to a structural dysfunction or previous surgical alteration. Squatting to just 90° of hip flexion is enough to generate a significant contraction within the gluteus maximus, biceps femoris, erector spinae, and soleus. Third, this study normalized the load for the conditions. So, if using a partial squat more load should be applied to get similar results. Lastly, it should be noted that this should not be used to completely replace a full squat unless the client has permanent limitations. When the client demonstrates functional dysfunctions (short muscles, lack of strength, lack of neuromuscular control, etc.) use this as a temporary method to improve control and strength as flexibility and coordination are worked on to eventually achieve a full range of motion squat.

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Effortlessly Maintain Your Ideal Weight With Ketogenic Eating

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Perhaps the most immediate and dramatic benefit of ketogenic eating is the opportunity for quick and efficient reduction of excess body fat. This also means easy, long-term maintenance of your ideal body composition. Ketogenic eating can make you an efficient fat-burning machine. When you are in full-blown keto, you enjoy complete dietary satisfaction, rarely feel hungry (even if you skip meals!), and never have to struggle, suffer, restrict calories, or force strenuous workouts in order to burn extra calories. Instead, you allow your body to naturally calibrate you to a healthy composition and weight.reset, you’ll learn the best way to ditch grains, sugars, and refined vegetable oils, and you’ll also discover the nutrient-dense, high-fat, low-carb primal foods with which to replace them. During the second week, you’ll focus on the supportive lifestyle behaviors that are essential to succeed with dietary transformation. These include optimizing your exercise patterns, dialing in your sleep, and implementing effective stress-management techniques. In your final approach to the 21-day mark, you’ll put it all together—thereby escaping carbohydrate dependency once and for all and plunging headlong into the world of fat adaptation.

Adopting a long-term ketogenic lifestyle is easier than you think.

You will likely notice immediate weight loss, largely due to a reduction in inflammation (and the ensuing fluid retention in cells throughout the body) and also because you will unlock stored body fat to burn for energy around the clock. It’s not uncommon for devoted enthusiasts to drop 10 to 15 pounds total, including 3 to 6 pounds of excess body fat, during a 21-Day Metabolism Reset.

Then, you’ll go keto, dropping your carb consumption to less than 50 grams a day and also likely lowering your protein to less than you typically consume, while also emphasizing nutritious, natural fats as your main calorie source. Your journey into nutritional ketosis should last for at least six weeks. Then, with your newly minted degree in fat- and keto-adaptation, you can consider and experiment with assorted long-term options, including going back into nutritional ketosis any time in the future to shed excess fat, protect against disease, and enhance cognitive and athletic performance.

Being fat- and keto-adapted means that you can veer off the plan now and then and not tailspin into a monthlong sugar binge. When you have this esteemed metabolic flexibility, you can wake up the day after eating cake by the ocean, or even a bunch more stuff on a weeklong cruise, and get right back into the groove—whether through fasting, a string of keto-aligned meals, or even strategic use of ketone supplements. Adopting this lifestyle means freedom from sugar cravings, fatigue, and overstimulation of the fight-or-flight response from excess carbohydrates. What could be better than that?

Sources:
1. Masino, Susan (ed.). Ketogenic Diet and Metabolic Therapies: Expanded Roles in Health and Disease. Oxford University Press, 2017.

2. Cahill, G.F. (2006). Fuel metabolism in starvation. Annual Review of Nutrition, 26: 1-22.

3. Rattan, S.I.S. (2006). Theories of biological aging: Genes, proteins, and free radicals. Free Radical Research, 40: 1230–1238.

4. Sohal, R.S., & Weindruch, R. (1996). Oxidative Stress, Caloric Restriction, and Aging. Science (New York, N.Y.), 273 (5,271), 59–63.

Source mindbodygreen.com

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Intermittent Fasting, Is Right For You?

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Almost everyone can benefit from intermittent fasting (IF), which—as its name implies—means alternating between periods of eating and not eating for various amounts of time. “Fasting is the oldest dietary intervention in the world,” writes Dr. Jason Fung in The Complete Guide to Fasting. “Because it differs from conventional dieting in so many important ways, fasting carries many distinct advantages.”

Among them, fasting is simple, free, convenient, effective, and allows you to enjoy life’s occasional indulgences. You can do IF on almost any plan, whether you’re vegan or paleo, and it gives your overworked digestive system a much-needed break.

IF challenges conventional health theories: Many practitioners skip breakfast, don’t count calories and go long hours—sometimes days—without eating. They think when you eat may be just as important as what you eat. And it gets results. Intermittent fasting’s numerous benefits include weight loss and chronic disease management.

At the same time, no one plan works for everyone, and that includes IF. Even Fung notes certain people shouldn’t do IF, including pregnant or breastfeeding women, underage people, and malnourished folks. He advises others like people with type 1 diabetes to proceed cautiously with fasting. While you can usually work with a credentialed health care expert and modify fasting to your condition, I’ve found people with these five issues should think twice about, and—in one case—absolutely avoid intermittent fasting:

1. You have gallstone disease.

When you fast, your gallbladder doesn’t release bile. As your liver continues to deliver bile, it becomes concentrated. Breaking you’re fast means your gallbladder could forcefully release sludge or small stones from that buildup that could get stuck in the bile duct. If you have gallbladder issues, proceed cautiously with IF. One study showed that among people with gallstone disease, a long overnight fast increased hospitalization risk.

2. You have an eating disorder.

Here’s my one big thumbs-down for fasting. A systematic review of IF’s potential harms mentioned eating disorders, and writer Emily T. Troscianko asked whether IF is “A Fast Route to Disordered Eating?” in an intriguing Psychology Today essay. If you have bulimia or otherwise struggle with other psychological eating disorders IF could exacerbate those problems. An eating disorder is one condition with which you absolutely should not do fasting. Rather, always work with your doctor when struggling with any sort of disorder.

3. You have adrenal fatigue.

Fasting can keep your stress hormone cortisol ramped up, stressing your already-overworked adrenals. One study with 16 young, healthy female volunteers who fasted for 48 hours had elevated cortisol levels, suggesting fasting could create additional stress. You’re probably not going to fast that long, but beware if you have adrenal fatigue or your adrenals are already overworked from chronic stress—fasting could make your condition worse.

4. Your thyroid is shot.

Your thyroid performs many functions, including balancing energy, body temperature, and emotions. When this tiny gland isn’t working correctly, numerous problems can result. Triiodothyronine (T3) is your active thyroid hormone. Studies show fasting decreases T3, so if you have mild to moderate hypothyroidism, you might want to reconsider intermittent fasting.

5. You’re sick.

Your body needs a steady supply of nutrients if you’re ill, and if you’re not eating you can’t get them. IF could also create physiological or metabolic stress: the last things you want to create when you’ve got a cold, flu, or another virus. At the very least, I recommend bone broth and a nutrient-dense protein shake or green drink to meet those nutrient requirements.

If you don’t fall into those conditions and want to try IF, start out slowly. Have a big dinner, close up the kitchen for the night, and then have breakfast as late as possible the following morning. That creates about a 12-hour or longer fasting window—most of it while you’re sleeping—that helps your body dip into those fat stores. Gradually increase that fasting time, but if you feel nauseous or otherwise unwell, please eat something. Don’t risk your health!

Source http://www.mindbodygreen.com

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Yoga Nidra and Consciousness: Chakras in Yoga Nidra

The awakening of consciousness through Nyasa releases tensions and lethargy, thereby healing illnesses

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According to Paramahansa Satyananda, Yoga Nidra actually begins with the experiencing of these chakras. The chakras are also known in other cultures, as we have seen with the Hopis in the USA, but also by the alchemists in Europe and the Inuits of Greenland and Canada, to mention but a few of the more evident examples.

Also: Yoga Positions for Beginners – 2 Things You Need To Know

In the deep Yoga Nidra, we use eight of the major chakras to contact the various planes of consciousness.
On my album, “Experience Yoga Nidra” (previously on cassette tape) I use the mantras (certain sound syllables) connected to each chakra. I also use visual symbols in accordance with the traditions of India and Europe.

When I started to produce “Experience Yoga Nidra” while teaching in the USA, the Indian musician Roop Verma was inspired to record the ancient musical symbols of the chakras. He was the first ever to do this. This special music has been merged with my text and guidance during the deep Yoga Nidra.

Chakras are often spoken of in connection with Kundalini Yoga, a set of methods and meditations that can be used to harmonize and awaken the psychic energy. (The name Kundalini Yoga, however, is also used as the trade mark of a contemporary movement – although they only teach standard yoga).

Kriya Yoga is probably the most profound and effective form of Kundalini Yoga. In an awesome way, it can strengthen the body’s energy field, remove depressions, increase creativity and open you up to a first-hand knowledge of the genuine mystical or spiritual aspects of life.

The chakras have corresponding areas in the brain. When they are relaxed and harmonized during Yoga Nidra, the release of unwanted states such as confusion and lack of concentration begins. People who awaken their chakras through yoga and meditation, open up to a previously unknown capacity for communication, insight, and creativity.

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