Trainer Janna

Vitamin D, also known as the “sunshine vitamin,” was identified in the 17th century by Dr. Daniel Whistler and Professor Francis Glisson when they discovered the causative factors of rickets.

Circa 1920, Sir Edward Mellanby worked with dogs raised exclusively indoors. He devised a diet that allowed him to unequivocally establish that rickets was caused by a deficiency of a trace component present in the diet and that cod liver oil (an excellent source of vitamin D) was an effective antirachitic agent.

Along with vitamins A, E and K, vitamin D is a fat-soluble vitamin. Vitamin D actually refers to several different forms. Two forms that are important in humans include:

Vitamin D2 (Ergocalciferol)- derived from plants
Vitamin D3 (Cholecalciferol)- derived from animal products and made in the skin when exposed to sunlight
In addition vitamin D has three analogs, each with different potencies:

Cholecalciferol - 1x
25 hydroxycholecalciferol - 5x
1, 25 dihydroxycholecalciferol - 10x
To learn more about each vitamin and mineral we need to stay healthy, check out the NASM guide to Micronutrients.

SOURCES OF VITAMIN D
Vitamin D can be synthesized in the skin after exposure to ultraviolet light or obtained from the diet either from unfortified or fortified food sources or supplements. Unfortified sources include animal products such as cod liver oil, sardines, mackerel, herring, tuna, salmon, and shrimp. Fortified sources include milk and some brands of alternative milks (rice, soy, almond, etc.).

Some vitamin D researchers suggest that approximately 5–30 minutes of sun exposure between 10 a.m. and 3 p.m. at least twice a week to the face, arms, legs, or back without sunscreen usually leads to sufficient vitamin D synthesis (and that the moderate use of commercial tanning beds that emit 2%–6% UVB radiation is also effective).

Individuals with limited sun exposure need to include good sources of vitamin D in their diets or consider supplements to achieve recommended intake levels.

Vitamin D supplements are also great for counteracting the symptoms of COVID!

METABOLISM
As with many nutrients, vitamin D is absorbed in the small intestine. It is transported through the lymphatic system by chylomicrons and stored in the liver, bone, brain, and skin.

Vitamin D obtained from sun exposure, food, and supplements is inactive and must undergo two hydroxylations in the body for activation. The first hydroxylation occurs in the liver, where vitamin D is converted to 25-hydroxyvitamin D [25(OH)D], also known as calcidiol. The second hydroxylation takes place in the kidneys, where it forms the physiologically active 1,25-dihydroxyvitamin D [1,25(OH)2D], also known as calcitriol.

REQUIREMENTS
The Recommended Dietary Allowance (RDA) for vitamin D ranges from 400-800 IU, depending on age, pregnancy/lactation status, skin color, sun exposure, diseases affecting nutrient absorption, and health status. This RDA is considered a daily intake that is sufficient to maintain bone health and normal calcium metabolism in 97-98% of healthy people.

It is important to note that numerous studies support much higher intakes for the prevention and/or management of a number of diseases, some of which will be mentioned later. These intakes can be as high as 10,000 IU/d, or >10 times the current recommended intakes.

MEASURING VITAMIN D STATUS
Serum concentration of 25(OH)D is the best indicator of vitamin D status. It reflects vitamin D produced in the skin and that obtained from food and/or supplements.

Based on a review of the data on vitamin D needs, a committee of the Institutes of Medicine (IOM) concluded that people are at risk for vitamin D deficiency at serum 25(OH)D concentrations

When clients want to change their body composition, such as losing fat or gaining lean mass, how will you determine if they are meeting their goals? You can use a weight loss calculator, BMI calculator, skinfold measurements, and more. There are many assessment techniques, each with benefits and drawbacks depending on the client you are working with.

The tips in this blog will complement what you learned during your personal training certification training and can be applied for future reference with your clients.

Body composition can be assessed by a variety of methods, including skinfold measurements, bioelectric impedance, and hydrostatic weighing (the standard other body composition methods are compared against).

These methods estimate the relative percentage of body weight that is fat versus fat-free mass (muscles, bones, water, connective tissues, organs, etc.). There are also methods for assessing changes in girth, such as circumference measurements and waist-to-hip ratios. Knowing the benefits and potential drawbacks of these methods will help you chose the right tools to track your client’s progress.

Skinfold Measurements

Skinfold measurements are a more common method for assessing body composition in the fitness setting. This method requires the use of calipers to measure the amount of subcutaneous fat beneath the skin. There are many valid formulas and measurement sites used to calculate body fat percentage. NASM uses the simple four-site Durnin (or Durnin-Womersley) formula.

The four sites are the biceps, triceps, subscapular, and iliac crest. All measurements should be taken on the right side of the body and then added together and compared against a calculation table. Avoid taking measurements immediately after exercise. It is essential that trainers practice locating and measuring the four sites, poor skills will translate into inaccurate results. While the Durnin formula works well for most people, there are other formulas that are population-specific .

Assessing body fat using skinfold calipers can be a sensitive situation for some clients, especially overweight or obese clients. Take measurements in a low traffic area to respect their privacy. Additionally, the accuracy of skinfold measurements decreases with larger clients, and may not be the most appropriate method for assessing their body composition. Consider other methods such as bioelectric impedance, circumference measures, scale weight, or even how clothes fit to evaluate progress. Obese clients realize they are carrying too much fat- you don’t need to discourage them with a number indicating just how obese they might be.

WHAT IS SCREW HOME ROTATION?
The knees have a "Screw Home" rotation that allows for full knee extension and flexion. There is an observable rotation of the knee during flexion and extension. During the last 30 degrees of knee extension, the tibia (open chain) or femur (closed chain) must externally or internally rotate, respectively, about 10 degrees. That might not seem all that significant, but this rotation is important for healthy movement of the knee.

Whether it is tibial-on-femoral rotation, as in an open chain exercise like in the leg extension machine, or femoral-on-tibial rotation, as in a closed chain exercise like the squat, rotation must occur to achieve full extension and then flexion from full extension.

This is due to factors including:

The shape of the medial femoral condyle. The condyles on the femur are shaped a bit differently than those elsewhere in the body. According to research, the articular surface (the end of the bone where two bones join to allow movement) on the medial femoral condyle has a 30 degree lateral curve. This curvature allows the tibia and femur to follow this curve with tibial-on-femoral rotation as well as femoral-on-tibial rotation.
The lateral pull of the quadriceps is a factor in the lateral rotation during the later phases of extension. (The quadriceps insert into the tibial tuberosity via the patellar tendon). When contracted, the quadriceps cause an anterior translation of the tibia on the femur.
This creates a passive tension in the anterior cruciate ligament (ACL) which contributes to external rotation. This passive tension helps stabilize the extended knee by resisting excessive anterior translation of the tibia or excessive posterior translation of the femur.
In order to unlock the knee from extension, the popliteus muscle must work to initiate internal or external rotation. The tibia must internally rotate slightly to allow for knee flexion in an open chain, and the femur must externally rotate for knee flexion in a closed chain. This mechanism of rotation contributes to proper movement at the knee.

THE IMPORTANCE OF FORM
Bottom line: Form is an essential component to low body activity due to factors such as the screw home rotation. The NASM CPT curriculum teaches a foot forward position with the knees lined up over the second and third toes to help individuals line up the lower body properly for optimal function.

Lining up your client properly can assist in making sure the tibia and the femur are in the proper position to facilitate healthy and natural movement at the knee. If the tibia is in a fixed external position, or the femur is in a fixed internal position, this can alter the mechanics of the knee and lead to increased chances of injury.

With this knowledge, the next time you bend or extend your knee, you will appreciate the complexities of the human body and understand that without good form, there is not good function.

WHAT IS THE PIRIFORMIS?
The piriformis is a tiny muscle that originates on the anterior surface of the sacrum, travels through the greater sciatic foramen, and attaches to the greater trochanter of the femur (1,2). It accelerates hip external rotation, abduction, and extension.

WHAT IS PIRIFORMIS SYNDROME?
Piriformis syndrome has traditionally been described as a referred neural pain in the posterior hip and leg caused by hypertrophy or spasm of the piriformis. The pain is caused by pressure applied to the sciatic nerve by the piriformis due to the passage of the nerve through or under the muscle (2).

Pain associated with this problem often mimics the signs and symptoms of lumbar nerve root compression or sciatica in the buttock and posterior leg. The client will often report sciatica-type symptoms and experience tenderness in the piriformis fossa. Pain when sitting is common, as is pain with hip flexion, adduction, and internal rotation.

SIGNS AND SYMPTOMS OF PIRIFORMIS SYNDROME
The signs and symptoms of piriformis syndrome are:

Pain in the buttock
Pain down the back of the hamstring, or posterior thigh
Pain when sitting
Pain when walking up stairs or inclines
decreased range of motion of the hip joint
While the signs and symptoms of the syndrome may be similar to other lumbo-pelvic pathology, the cause of piriformis syndrome remains relatively undefined as to reasons for development of spasm or hypertrophy of the muscle.

See "Is The Piriformis Tight? Really?" for an additional perspective on symptoms, causes, and solutions of Piriformis Syndrome.

It is interesting to note that a description of the syndrome is found in most medical texts, yet the criteria for diagnosing piriformis syndrome and pathophysiology still remains a controversial issue (3,4).

However, the reason why the piriformis is hypertrophied or in spasm is often described as "undefined and confusing." If the practitioner considers the principles of the kinetic chain and dysfunction of its linked components, it is not difficult to hypothesize why the piriformis may become involved in an impingement of the sciatic nerve. If the client has chronic tightness of the hip flexor, the gluteus maximus will become reciprocally inhibited (1).

This is significant because of the functional responsibility of the glute to decelerate medial femoral rotation during heel strike or functional movements. Since the piriformis is a primary external rotator of the femur, it becomes synergistically dominant in controlling the femur.

This type of dominant function has the potential for causing the spasm, hypertrophy, or tightness described in most texts. The external hip rotators have also been noted as being the least stretched muscles of the lower body (5).

PIRIFORMIS SYNDROME TREATMENT AND THERAPY
If a client complains of pain in their buttocks, hip rotators, or the lumbo-pelvic complex in general, the health and fitness professional should first instruct the client to visit their medical professional. If a client has been released from therapy or their doctor and the pain persists, an effective corrective exercise strategy for correcting this type of dysfunction would be to first release the hip flexor through appropriate integrated flexibility techniques, then implement reeducation of the gluteus maximus through isolated strength training.

WHAT ARE ERGOGENIC AIDS?
An ergogenic aid is simply something that enhances athletic performance. In the realm of nutrition, this falls under the purview of ergogenic foods (foods that enhance sports performance through their specific nutritional benefits).

Here is a list of some ergogenic foods and their performance perks.

ERGOGENIC FOODS FOR SPORTS PERFORMANCE
WATERMELON JUICE
Consuming watermelon before exercise helps cut recovery time and boost performance. Watermelon is a rich source of citrulline, an amino acid that can be metabolized to arginine, a conditionally essential amino acid for humans. Arginine is the nitrogenous substrate used in the synthesis of nitric oxide.

It plays an essential role in cardiovascular and immune functions by accelerating lactic acid removal, and allowing better physical performance by enabling athletes to carry out more intense training. The end result? A faster recovery after each workout. Dose: 500 mL of natural watermelon juice.

(Collins, 2007) (Tarazona-Diaz, 2013)

BEETROOT JUICE
Beetroot and leafy greens are good sources of nitrate. Dietary nitrate is absorbed rapidly from the stomach and small intestine. Six days of dietary nitrate supplementation in the form of beetroot juice (~0.5 L/d) has been reported to reduce pulmonary oxygen uptake (VO₂) during submaximal exercise and increase tolerance of high-intensity work rates, suggesting that nitrate can be a potent ergogenic aid.

(Cermac, 2012)

GREEN TEA
A study testing the effect of green tea extract (GTE) found that over 10 weeks, endurance and exercise performance was boosted by up to 8-24% with 0.5% GTE supplementation. Researchers at the Biological Sciences Laboratories of Kao Corp., Tochigi, Japan, said the 8-24% increase in swimming time-to-exhaustion was accompanied by lower respiratory quotients and higher rates of fat oxidation.

The results indicate that GTE is beneficial for improving endurance capacity and support the hypothesis that the stimulation of fatty acid utilization is a promising strategy for improving endurance capacity.

Results came from the equivalent of drinking about 4 cups of green tea a day.

(American Physiology Society, 2005)

COCONUT WATER
In a study by Saat et al., eight healthy male volunteers exercised at 60% of VO2max in the heat until 2.78 +/- 0.06% of their body weight (BW) was lost. After exercise, the subjects sat for 2 hours in a thermoneutral environment and drank a volume of plain water, coconut water and a carbohydrate electrolyte beverage on different occasions representing 120% of the fluid loss.

Coconut water was found to be significantly sweeter, caused less nausea, and fullness without stomach upset, and was also easier to consume in larger amounts compared with a carbohydrate electrolyte beverage and plain water ingestion.

Researchers concluded that the ingestion of fresh young coconut water could be used for whole body rehydration after exercise.

(Saat, 2002)

PEPPERMINT
Peppermint is a natural herb with analgesic, anti-inflammatory, antispasmodic, antioxidant, and vasoconstrictor effects.

In a study of twelve healthy male students, one 500 ml bottle of mineral water, containing 0.05 ml peppermint essential oil, was consumed for ten days. The results of the experiment showed peppermint essential oil to have favorable effects on performance, gas analysis, spirometry parameters, blood pressure, and respiratory rate in the young male students who completed a standard treadmill exercise test.

The plausible explanations were relaxation of bronchial smooth muscles, increase in the ventilation and brain oxygen concentration, and decrease in the blood lactate level.

(Meamarbashi, 2013)

PROTEIN
The International Society of Sports Nutrition (ISSN) proposes that exercising individuals need approximately 1.4 to 2.0 grams of protein per kilogram of bodyweight per day, with the actual amount dependent upon the mode and intensity of the exercise, the quality of the protein ingested, and the status of the energy and carbohydrate intake of the individual. Concerns that protein intake within this range is unhealthy have been unfounded in healthy, exercising individuals.

Optimally, one should seek to obtain protein requirements from whole foods (e.g. eggs, meat, fish, poultry and dairy as well as vegetable sources such as soy and legumes). Supplemental protein is also a safe and convenient method of ingesting high quality dietary protein. The timing of protein intake shortly after exercise can improve recovery and lead to greater gains in fat free mass.

(Campbell, 2007)

FAT: MEDIUM CHAIN TRIGLYCERIDES (MCT)
The effects of regularly consuming medium-chain triglycerides (MCT) on swimming endurance was investigated by Fushika et al. The group fed MCT showed significantly greater swim capacity than the control group. These findings were evident in both trained and untrained subjects.

The major metabolic consequences of the adaptations of muscle to prolonged MCT administration during endurance training were higher activities of enzymes involved in energy production and macronutrient utilization.

MCTs provide about ten percent fewer calories and are more rapidly absorbed by the body and more quickly metabolized as fuel because they cross the mitochondrial membrane very rapidly, and do not require the presence of carnitine, compared to long chain fatty acids. The result of this accelerated metabolic conversion is less fat storage and greater conversion into fuel for immediate use.

MCTs have gained in popularity with athletes seeking to increase energy levels and enhance endurance during high-intensity exercise, as well as serving as an alternative energy source (i.e. nutritional ketosis) for athletes on high-protein, low-carbohydrate diets. Additionally MCTs can be quickly mobilized in the post-exercise recovery phase to rebuild muscles and prevent catabolism.

The dose of MCT (e.g., organic extra virgin coconut oil) is about 1/4 teaspoon several times daily. MCTs can cause nausea and gastric discomfort, so start low and increase dose only as tolerated.

See also: Foods High in Healthy Fats

(Fushika, 1995) (Dean, 2013)

CARBOHYDRATES
Carbohydrates and fats are the two primary fuel sources oxidized by skeletal muscle tissue during prolonged endurance exercise. The contribution of these fuel sources depends on the exercise intensity and duration, with a greater contribution from carbohydrate as exercise intensity increases.

Which is better, the front squat or the back squat? The answer to this ongoing debate depends heavily on the client.
Both the front and back squat movements require hip flexion, knee flexion and dorsiflexion during the eccentric phase and hip extension, knee extension and plantar flexion during the concentric phase.

MUSCLES WORKED IN FRONT SQUATS & BACK SQUATS
Both front squats and back squats work the same muscle groups; prime movers include gluteals and quadriceps; synergists include the hamstrings; and stabilizers include the deep abdominal muscles (transverse abdominis).

EMG activity in each muscle group (quadriceps, hamstrings, gluteals) between the two lifts is nearly identical (1). Because of the inherent change in the position of the center of mass of the bar between the front and back squat lifts, the back squat results in decreased back extensor muscle activity (erector spinae) (1). Back squats also create greater compressive (downward) forces at the knees. However, shear (side to side) forces at the knee are identical in both lifts (very minimal) (1).

The primary difference between the two lifts is actually upper body mechanics. Individuals who lack shoulder external rotation may have a difficult time performing a back squat. These individuals are hard pressed to get the bar racked and held in the proper position across the upper back due to poor shoulder and thoracic spine mobility. These individuals usually display an upper crossed syndrome (rounded shoulders and forward head), typically seen in those who spend a lot of time driving or working on the computer.

The front squat does not require external rotation at the glenohumeral joint. However, some individuals find the position of the bar across the shoulders uncomfortable; especially if they have acromioclavicular joint (AC) joint dysfunction.

There is anecdotal evidence that front squats are safer on a client’s lower back, but this has not been proven definitively in research. Conversely, clients tend to be able to lift heavier loads with back squats.

The bottom line, both exercises help target the musculature of the lower extremities and can be beneficial developing muscular growth, strength and power. The exercise you choose should depend on the client’s squat posture / technique and the client’s preference. It is doubtful you’ll notice significant performance abilities by choosing one lift over the other. Remember, all training is cumulative.

If you want to learn more about different kinds of squats, check out the blog post link.

Reference:

Gullett JC, Tillman MD, Gutierrez GM, Chow JW. A biomechanical comparison of back and front squats in healthy trained individuals. Journal of Strength and Conditioning Research. 2009 Jan;23(1):284-92.

Keeping athletes and clients performing at their peak while also avoiding heat-related illnesses takes preparation and planning. Bodies need time to adapt to the increased physiological demands of training in warm environments. But even with preparation and planning, heat illnesses can and still do occur.

Heat illnesses generally affect those with lower levels of fitness. More fit individuals are typically better able to tolerate exercising in the heat, acclimate quicker, and sweat more. To help clients and athletes meet the demands of training in the heat, acclimate them to the warmer environment over a 10 to 14 day period, balancing the length of training sessions with intensity (i.e., long duration with a low intensity, or short duration with a moderate intensity). Adequate hydration is another key component to preventing heat illnesses, as inadequate hydration decreases the body’s sweat rate.

Encourage replacing fluids lost to sweat and urination, and offer hydration breaks during training . (Contrary to Coach Boone’s words in the iconic football movie “Remember the Titans,” water is not for cowards nor does it make you weak.) Teach participants strategies for monitoring fluid loss, such as daily weigh-ins, and pre- and post-workout weigh-ins if necessary .

Evaporation of sweat is the body’s key mechanism for staying cool. Humidity decreases the rate of sweat evaporation, as can limiting the skin’s exposure when wearing full training gear. If possible, reduce the amount of gear and clothing worn, especially during the acclimation period . Selecting moisture wicking fabrics will speed the rate of evaporation over less permeable materials. Also attempt to schedule trainings during the cooler times of the day, either in the early morning or early evening, or move them into climate controlled indoor venues when available.

Heat can also affect children differently, since they have immature thermoregulatory systems, including both a delayed response and limited ability to sweat . They may require a longer timeline to acclimate, incorporation of more rest breaks, extended warm-ups and cool-downs, and frequent reminders to hydrate .

If you have clients who are interested in stand-up paddleboarding (or just want better balance and strength), this is the workout to try. While it’s true that dry-land training can only get you so far when it comes to stand-up paddleboarding (SUP), the OPTTM model’s focus on Stabilization Endurance and Strength Endurance in Phase 1 and Phase 2 can give newcomers and experienced paddlers alike a leg up. “The ever-changing challenge of SUP frequently results in fatigue as the leg muscles are firing and the body is constantly working to maintain balance,” says Jerry Napp, MA, NASM-CPT, CES, PES, a stand-up paddleboarder, based in Weeki Wachee, Fla. In his view, dry-land training to improve dynamic balance and stabilization will ultimately improve performance in SUP. Plus, Napp points out, research has shown that improvement in strength improves balance—and the OPT model is a win here as well.

Adding Instability The workout here features exercises with increased instability through the use of BOSU trainers, core boards, and stability balls. That said, keep it safe, and be sure that clients use proper form. “Falling out of balance in a gym environment can be more dangerous than falling off a paddleboard into the water,” Napp says.

Building Balance For clients interested in SUP, add the following routine two or three times per week to help improve stability on the board. Work in order through each step, to progress from flexibility and movement preparation (moves 1 through 4, which can also be performed before SUP outings) to stabilization strength exercises (moves 5 through 11). Aim for one set of moves 1 through 4 (as indicated) and two sets of moves 5 through 11 (8 to 12 reps each), with a focus on form, balance, and proper breathing.

WHAT IS LOW BACK PAIN?
Low back pain is not a specific disease; rather it is a complaint that may be caused by a large number of underlying problems of varying levels of seriousness. The majority of low back pain does not have a cause but is believed to be the result of non-serious muscle or skeletal issues.

Low back pain is generally classified into three types: mechanical, non-mechanical, and referred pain from organs (Manusov, 2012). Cohen, Argoff, and Carragee (2008) suggest that mechanical low back pain makes up 90% or more of the cases.

According to Dr. Everett Hills, most patients that experience mechanical low back pain report a history of different events leading up to the pain. These include lifting heavy objects, prolonged sitting, or maybe motor vehicle accidents and falls. To test for back pain, Hills suggests beginning with an assessment looking for asymmetries in hip musculature and testing range of motion throughout the spine. In the majority of cases, low back pain can be associated with musculature asymmetries and range of motion deficits.

MUSCLE IMBALANCE LIKELY CAUSING LOW BACK PAIN
These are indicative of muscle imbalances, likely causing the muscles of the low back to become compensatory and overworking the supportive structures (i.e., ligaments and tendons). Thus, the most likely cause of pain is sprain or strain to the soft tissue structures that support the lumbar spine.

Based on the given information for mechanical low back pain, the low back is not the cause but the recipient of pain. Specifically targeting the low back with any sort of massage or relaxation technique may work to momentarily relieve some of the pain, but it does not get to the root of what is causing the low back to become overworked.

OVERHEAD SQUAT ASSESSMENT FOR CORRECTING LOWER BACK PAIN
For the fitness professional it is essential to perform some sort of a movement assessment that addresses total body strength and range of motion. For example, using the overhead squat assessment and watching for the client to maintain a neutral spine throughout the squat.

This assessment is an easy to use tool that can indicate whether or not there is a mechanical relationship to the client’s low back pain. The most common movement compensation seen with low back pain is an extension of the lumbar spine during the squat, also known as an anterior pelvic tilt.

An anterior pelvic tilt indicates a muscle imbalance with overactive low back and hip flexor muscles and underactive core and hip muscles, as well as a possible range of motion deficit in hip extension. In this scenario, if a client is experiencing low back pain, it is generally not the low back that is causing the problem; it is the movement imbalance around the hips. Therefore, there are several areas which should be foam rolled.

WHAT IS FOAM ROLLING?
Foam rolling is a form of self-myofascial release (SMR) that is quickly becoming a popular method to use in situations with acute pain or injuries. It is often said that by using a foam roller, one can reduce the tension and pain in several areas of the body. While this may be beneficial, there are several mechanisms that may relate to a change in the sensation of pain.

For example, simply rubbing the skin over an injury can change the amount of pain one feels at that moment, but it has no influence or benefit on the tissue beneath the skin. In order to achieve myofascial release there must be a low load dragging force across the tissues and this must be sustained for a period of time.

Unfortunately, most people using a foam roller roll too quickly over the skin and may be changing only the sensation of pain but not inducing myofascial release.