Written by Scott Kolasinski
During June 15th and 16th, I visited the 2009 International Society of Sports Nutrition (ISSN) Conference in New Orleans, LA. The ISSN is the only nutritional organization devoted solely to sports nutrition so I look forward to attending this every year.
The following is a quick summary of the lectures.
Resistance Training Exercise Prescription: Understanding the Impact of Choices Made at the Upper Regulatory Level – William Kraemer, Ph.D
Exercise Sequencing Strategies
Dr. Kraemer did a review of the basics of periodized training, the SAID Principle, exercise order. He showed the affects of endurance versus low rep protocols on skeletal muscle morphology. Nutritional interventions (supplements, hydration status) and environmental conditions, such as heat, age, gender, will all dictate the magnitude of genetic expression. Coaches need to train the entire strength-velocity curve of a muscle contraction. For example, training for an increase in strength only will not result in an increase in power alone. We still need to also train for power specifically.
Gender differences exist:
- Women might oxidize less protein during exercise than men…women use more fat for energy.
- Women synthesize less muscle protein than men when amino acids were provided after exercise.
- Women may require more protein/kg to maximize muscle growth.
- Women use more fat than men during exercise.
- Women maintain reproductive function in energy-demanding times.
- Women have better fat use with an increased fat intake.
- Women use less glycogen during resistance exercise than men.
- Women cannot carb-load to the same extent as men.
- Women oxidize less carbohydrate & more lipid during resistance exercise.
Final thought: “We have a lot to learn….as I have just shown you the tip of the proverbial iceberg of things that are stimulated with a resistance training workout..
…….context is always the key”
Nutritional Assessment of the Athlete – Doug S. Kalman, Ph.D, RD, FACN
An athlete’s nutritional needs are based on the energy system demands of their sport, age, gender, lifestyle, health status, training routine, frequency, goals, and conditioning amongst other factors. Genetics are an underappreciated issue.
In order to make a lifestyle routine for an athlete, in general we should look at the basic procedures in nutrition care plans for assessment.
Because of the many complexities involved in an athlete’s diet, we should take advantage of the many technological advances that are available. Dr. Kalman suggested the MedGem device to assess an athlete’s calorie needs. There are other devices out there, but the MedGem is the only one he knows that is FDA-cleared. This means that it has undergone vigorous testing of reliability, accuracy, and repeatability.
Role of Myogenic Regulatory Factors as Regulators of Transcription & Myogenesis: Effects of Nutritional Modulation – Darren Willoughby, Ph.D
This was a complex lecture of molecular biology that described the number of nutritional factors that influence skeletal muscle recovery from exercise. We know that resistance exercise may result in muscle hypertrophy, or a thickening of the muscle fibers. This lecture looked at one aspect of the molecular biology behind how that might happen and the nutritional influences on it.
Myogenic regulatory factors’ (MRF’s) initiate transcription of DNA, but are not understood as well in satellite cell activation. Two nutritional supplements, creatine and whey protein, seem to upregulate MRF’s, but the mechanism is still unknown. More research is needed in this area of research.
Energy Drinks – Jay Hoffman, Ph.D
Energy drinks are now a $5.7 billion industry. The primary ingredient is caffeine and may contain up to 830mg caffeine. Usually other ingredients are included to enhance the effects of caffeine.
Some side effects of high doses of caffeine are insomnia, nervousness, headache and tachycardia. Caffeine should be used with caution in hypertensive individuals as it may lead to a dangerously high blood pressure. Drinking Redbull with alcohol can cause underestimation of intoxication and lead to potential lethal consequences.
Caffeine does appear to:
- increase energy metabolism
- enhance exercise performance (reaction time)
- increase focus, alertness and energy.
Nutrigenetics and Athletics – State of the Art Today – Jan Debenedetto
One of the hot topics in the nutrition industry that is growing is nutrigenomics, or the concept of understanding how nutrition influences specific genes. This lecture gave a summary of common currently known genetic variations that can be addressed with nutrition, however, it must be emphasized that the environmental influences to our genes must always be considered.
The field is in its infancy, so we have many more questions than answers. However, there are a number of genetic variations that are known today whose health consequences can be effectively addressed via the diet and supplemental nutrition. Today, anybody can get his/her genetic makeup mapped.
A couple of quick stats concerning genes and exercise:
- There are more genes that are up-regulated in “Active People” than in “Sedentary People”.
- Sedentary people have more genes up-regulated that are associated with catabolism.
- If you want to create more active genes from when you were once sedentary, you need to be active for at least 8 years. What are the minimums of activity to make this happen are unknown.
Lastly, certain individual genes do not mean you will exhibit the gene. For example, the most common gene for “Beer Bellies” is also found in sprinters.
Glycine Propionyl-1-Carnitine and Repeated High Intensity Exercise – Pat Jacobs, Ph.D
This lecture was one of three that involved discussing the potential benefits of a supplement called glycine propionyl-1-carnitine (GPLC) for increasing concentrations of L-carnitine, a naturally occurring substance found in most body cells, in muscle. Dr. Jacobs presented a study to see if supplementing with GPLC would improve repeated bouts of high-intensity exercise.
Dr. Jacobs’s research concluded GPLC:
- increases resting nitric oxide (NO) concentrations in untrained and resistance trained men,
- increases the NO response to occlusion in resistance trained men,
- potentially spares muscle carnitine during aerobic training,
- potentially increases lactate threshold,
- short term application increases anaerobic work capacity in resistance trained men with reduced lactate accumulation,
- provides effects in a combined time/dosage manner.
According to his research, 1 g of GPLC is just as effective as 3 or 4.5g of GPLC. More research is needed.
Potential Benefits of Supplemental Carnitine in Relation to Exercise – Richard Bloomer, Ph.D
Carnitine is considered a water soluble vitamin that is synthesized in the liver and kidneys (0.16-0.48mg∙kg-1∙day-1 (reabsorb ~95% from kidney). It is transported to and stored primarily in skeletal muscle, heart, brain, and neural tissue. There is a significantly higher content in skeletal muscle vs. plasma (40-100 times higher).
The potential benefits of carnitine supplementation include: enhanced circulation, may improve fatty acid and carbohydrate metabolism in mitochondria, antioxidant properties – may reduce the potentially harmful effects of reactive oxygen species (ROS).
Thus far, 1.5 or 4.5 grams/day GPLC is an effective to bring about the benefits greater carnitine concentrations. However, Dr. Bloomer warned that the lab-tested conditions do not necessarily translate to performance benefits in sport. For example, an improvement in the Wingate test, a measurement of anaerobic power, does not mean GPLC creates more powerful Olympic weightlifters. More research is needed.
Carnitine Formulations for Sports: Promises and Pitfalls – Dallas Clouatre, Ph.D
There is a “carnitine paradox” – high initial glycogen levels lead to carnitine becoming unavailable for oxidation of fats at the transition from rest to activity and
at elevated VO2max.
There are three basic options for overcoming this paradox.
1) increase uptake of supplemental carnitine into muscle by insulin-related actions:
- Elevate insulin via simple sugars or via an insulin mimetic such as Russian tarragon or an active form of (–)-hydroxycitrate
2) alter tissue retention and compartmentalization:
- Supplement with choline
3) alter muscle fuel selection to favor fatty acid oxidation while preserving glycogen:
- Supplement with astaxanthin
- Supplement with an active form of (–)-hydroxycitrate
Phospholipids and Sports Performance – Ralf Jäger, Ph.D
Phosphatidylserine (PS) is an essential component of all biological membranes and is required for normal cellular structure and function. The participation in physical activity often challenges a variety of physiological systems; consequently, the ability to maintain normal cellular function during activity can determine sporting performance. PS has been established as a safe oral supplement capable of attenuating the serum cortisol and creatine kinase responses to acute exercise stress.
In addition to physical stress, PS supplementation benefits subjects suffering from mental stress. PS supplementation has been reported to improve mood in a sub-group of healthy young adults when faced with a stress.
A recent study by Kingsley et al. showed no effect of oral PS supplementation on markers of muscle damage or perceived soreness, however, PS tended to improve sprint and exercise performances when compared to placebo. These findings do suggest that PS might possess ergogenic properties. The effective daily dosages in sport studies range from 300 to 800 mg PS for short-term application (10–15 days) and from 300 to 400 mg PS for 3 to 4 weeks for mental stress.
Dr. Jager’s study concluded six weeks of 200mg/d PS supplementation did not improve perceived stress levels in golfers, but it did significantly improve the number of good ball flights during tee-off which might result in improved golf scores.
Tolerating Food Intolerances – Managing Nutritional Challenges During Training – Mona Rosene, MS, RD
Here is the difference between a food allergy versus food sensitivity: During a food allergy the immune system incorrectly identifies a protein as a threat and attempts to protect the body by releasing histamine. A food intolerance is not related to the immune system. It is usually a GI response and/or a delayed response, for example lactose intolerance. We get allergies from genetics, exposure to food and other allergens (ex. dairy before 1 years old), state of GI tract “barrier”, and excessive response of the immune system.
A concern with a food allergy is inadequate protein intake. This is because most people are allergic to higher protein foods such as dairy, eggs, soy, meat, fish/shellfish, legumes, peanuts, tree nuts. People with food allergies typically have inadequate fat intake. Higher protein foods that may be needed to be avoided are also usually higher in fat. Low allergen foods are low in fat, such as veggies, rice and fruit. As such, athletes with food allergies have difficulty consuming enough calories.
Athletes with food intolerances may have to avoid the food altogether, but food intolerances are usually dose dependent. For example, for some milk is intolerable but yogurt is not. Careful book keeping is best.
In general, eat good whole foods and protein powder is the easiest way to manage food allergies and intolerances.
A Practical Look at Key Nutritional Supplements for Strength & Power Athletes – Colin Wilborn, Ph.D
Four nutritional supplements have support for being considered effective for strength and power athletes:
1) Creatine – 3-5 grams per day
2) Protein supplements – whey, casein and even a glass of milk appear to benefit strength athletes. Timing is essential: post-workout boosts protein synthesis the best.
3) HMB (hydroxy-beta-methylbuterate) – an anti-catabolic amino acid that preserves muscle that may be used for energy instead.
4) Beta-Alanine – increases power and reduces fatigue. Appears to work best in conjunction with creatine. Whether or not it works alone is less conclusive. Side effects, such as parathesia – a tingling, prickly sensation that may occur in the face, arms, hands and/or buttocks – occurs less often in a slow-releasing capsule.