Monthly Archives: April 2012

The Metabolic Window

On Blast:  CHO or Protein for post-workout recovery?

A metabolic window refers to a time period of approximately 30-60 minutes post-exercise, then again 2 hours later.  During this time, a balance between the right proportion of CHO and protein can help the body in recovery following a strenuous workout.   Consuming the balanced snack/meal after the window has closed can result in as much as 85% less protein synthesis necessary for muscle recovery.  High glycemic index CHO results in higher muscle glycogen 24 hours after vigorous exercise (think PBJ sandwich, greek yogurt & granola, or fruit & cheese).

Recovery nutrition can:

  • Reduce an athlete’s susceptibility of becoming sick
  • Avoid a negative protein balance
  • Avoid muscle hypertrophy
  • Improve body responsiveness to recover after a strenuous workout
  • Minimize muscle catabolism

Recommendations:

  • CHO intake post-exercise increases insulin levels = promotes uptake of glucose into the muscles (restores muscle glycogen)
  • Combination of CHO and protein intake has proven to be more effective in recovery than focusing solely on either alone.
  • 2:1 CHO to protein intake for resistance exercise
  • 4:1 CHO to protein intake for glycogen-depleting exercises (distance running)

Verdict:  A combination is best!  Don’t miss your “window” of opportunity for recovery…har har har

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Total Body Weight Change During Training

On Blast:  Weight gain during training

A strength-to-weight ratio is the measurement comparison of fat free mass to fat mass (equation = fat free mass/fat mass) in the body.  A higher strength-to-weight ratio is preferred because it reflects higher free fat mass and less fat mass.  I often get asked why weight can change so much during the beginning of new exercise regimens or as the intensity increases during existing training routines. There are 3 scenarios substantiating how strength-to-weight ratio effect total body weight.

  • Maintaining fat free mass as fat mass is decreased results in a lower total body weight, which effectively increases the strength-to-weight ratio.
  • Increasing free fat mass while maintaining fat mass, increases total body weight, as well as a strength-to-weight ratio.
  • Increasing free fat mass while lowering fat mass, lower total body weight and increases strength-to-weight ratio

It’s really not enough to look at weight alone when you are assessing strength-to-weight ratio.  You need to look at your body’s composition.  Are you increasing or decreasing free fat mass or fat mass?  Tracking weight change does track calorie needs, but it doesn’t measure how the energy is being balanced.  Keeping track of body composition and strength-to-weight ratio can better assess your progress.

Verdict:  Track that body composition! 

Another Reason to Love the Carbs…

On Blast:  CHO Intake for Athletic Training

It’s spring and I feel like everyone I know is either training for a muddy buddy, a race of some sort, or a triathlon.  The more I visit with these individuals, the more I am surprised by their dietary intake and disdain for our friend, The Carbohydrate (CHO).  Let’s focus on aerobic training (biking, swimming, running, etc.).  As you increase your ability to efficiently intake and utilize oxygen, your body does the same with burning fat.  FACT:  you cannot burn fat without fueling the process with a CHO.  For chem nerds, think of CHOs as that process’ limiting reagent/factor.

CHO Dietary Intake Endurance Results:

  • High-fat diet- maximal endurance time of 57 minutes
  • Normal mixed diet-  endurance rises to 114 minutes
  • High CHO diet– maximal endurance rises to 167 minutes

Verdict:  Athletics should consume between 7 – 10g CHO /kg of body weight per day. 

1 kg = 2.2 lbs.  An athlete weighing 150lbs should consume 477-681 g CHO daily (68.18kg x 7-10g).