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Does a High Fat, Low Carb Diet Improve Endurance Performance?

Posted by Dr. Robert Portman on 10/8/2018 to Performance Tip Of The Week
Does a High Fat, Low Carb Diet Improve Endurance Performance?
The argument that a high-fat low-carb diet improves endurance performance is compelling. The average endurance athlete has about 2,000 calories of glycogen in their muscles. Even the leanest marathoner has close to 50,000 calories of fat. It makes sense that increasing fat consumption at the expense of carbohydrate, would lead to extended endurance since more fuel would be available to working muscles. Many trainers and nutritionists promote this proposition. Increase the fat, reduce the carbs and exercise performance goes up. Unfortunately, the scientific evidence does not support this proposition.

Hero Amino Acids #3 - Glutamine

Posted by Dr. Robert Portman on 9/17/2018 to Performance Tip Of The Week
Hero Amino Acids #3 - Glutamine

For endurance athletes, glutamine is particularly important. It is the most prevalent amino acid found in muscle cells accounting for almost 70% of  the muscle cell's free amino acid content. During moderate to intense exercise, glutamine levels are depleted- as much as 70%. Glutamine has been shown to have two important roles regarding muscle cells.


Slowing Muscle Protein Breakdown

Posted by Dr. Robert Portman on 9/10/2018 to Performance Tip Of The Week
Slowing Muscle Protein Breakdown
A popular misconception about building lean body mass is all you to do is stimulate the pathways that turn on muscle protein synthesis. This is only half the issue. Your lean body mass is a dynamic process. At all times, we are building new muscle protein (anabolism) and simultaneously breaking it down (catabolism). The key is net protein balance. When protein synthesis is greater than protein breakdown, we have a net positive balance and we increase lean body mass. When protein breakdown exceeds protein synthesis we have a negative protein balance and we decrease lean body mass. Normally we are at balance neither increasing or decreasing lean body mass. However the goal of most endurance athletes is to increase lean body mass. Understanding the factors that cause protein breakdown help us better achieve this goal.

The Switch That Controls Lean Body Mass

Posted by Dr. Robert Portman on 9/5/2018
The Switch That Controls Lean Body Mass
Most of the muscle adaptations that increase strength and endurance occur in the interval following moderate to intense exercise. Central to these adaptations is the repair and rebuilding of muscle protein. Although your muscles have multiple mechanisms to activate muscle protein synthesis the central mechanism involves a protein called mTOR. mTOR is a critical cellular switch that activates the cellular machinery responsible for repairing and building new muscle mass.

Cortisol - The Good. The Bad. The Ugly

Posted by Dr. Robert Portman on 8/30/2018 to Performance Tip Of The Week
Cortisol - The Good. The Bad. The Ugly
Most endurance athletes are familiar with cortisol, a catabolic hormone. In other words, it breaks down muscle tissue. Cortisol has a pretty bad image, especially among the endurance athletes. Yet it plays a vital role in helping athletes perform.

How Much Protein Should I Consume?

Posted by Dr. Robert Portman on 8/21/2018 to Performance Tip Of The Week
How Much Protein Should I Consume?
One of the more controversial nutrition questions is the amount of protein that should be consumed daily? According to the recommended daily allowance, protein intake should be about 0.36 g/lb of body weight. That means a 150-lb person should consume 54 grams of protein per day as shown in the Table below. The problem with the government allowance is the nutritionists who developed it were using sedentary adults as their models. Furthermore, the government recommendation is based on the fact that this level would maintain zero nitrogen balance, which means you would neither gain nor lose protein.