Essentials of Nutrition for Sports

• Dr. Edmund R. Burke Ph.D., Prof

essor of Exercise Physiology,

University of Colorado at Colorado Springs.

• Dr. Peter B. Raven, Ph.D., Prof

essor of Exercise Physiology,

Cardiovascular Research Institute,

University of North Texas Health

Science Center.

• Dr. John L. Ivy, Ph.D., Professor, Department of Kinesiology,
  University of Texas at Austin.
  
  
  • Dr. John Seifert, Professor of Exercise Physiology, Human
    Performance Lab, St. Cloud State University.”
  
  
  
  

Protein Replacement Uncertain Truth Ivy et al, JAP, 2002

12

In an article published in the

Journal of Applied Physiology,

John Ivy might have shown that protein helps glycogen recovery.

John Ivy has received a $45,000 grant from PacificHealth

Laboratories (Endurox R4) for research.

13

Seven subjects were studied on three occasions. This study purported to measure glycogen replenishment after

(a) a carbohydrate-protein (CHO-PRO) supplement, (b) a supplement of the same amount of carbohydrate (low carbohydrate, LCHO), and (c) a supplement with the same caloric content as the carbohydrate-protein mixture (high carbohydrate, HCHO).

Muscle glycogen was measured by nuclear magnetic resonance

spectroscopy, not by traditional muscle biopsy.

The three supplements were given in two feedings: immediately

after exercise and two hours post exercise.

The results of the study are illustrated in

Figure 9

.

There are at least three problems with this study:

12 Ivy, J.L., et al. (2002). Early post exercise muscle glycogen recovery is enhanced with a carbohydrate-

protein supplement. Journal of Applied Physiology. 93(1337).

http://jap.physiology.org/cgi/reprint/

93/4/1337?maxtoshow=&HITS=10&hits=10&RES

ULTFORMAT=&author1=ivy&searchid=110134509

3806_9463&stored_search=&FIRS

TINDEX=0&sortspec=relevance

. Accessed 11-25-2004.

1. How Much Fat?

The study muddies past research because all supplements

contained some fat. How much fat is unclear.

The abstract says each of the two carbohydrate supplement

feedings (LCHO and HCHO) contained 6 grams of fat. However, in the body of the article it is reporte

d that subjects in the carbohydrate

trials received only 3 grams of

fat per supplement feeding. This

difference would mean that groups were not isocaloric; the protein-carbohydrate group would have recei

ved an additional 54 calories.

I asked researcher Ivy about this

in an e-mail. He replied: “The

subjects received a total of 6 g of fat; 3 g with each CHO supplement. We weighed out the fat supplements in 3 g amounts (in a little paper cup).”

Figure 9. Ivy. JAP, 2002. Total muscle glycogen storage in the vastus lateralis during 4 h of recovery from intense cycling. Treatments were with CHO-PRO, LCHO, and HCHO supplements provided i

mmediately after and 2 h after

exercise. *Significantly different from HCHO and LCHO (

P<0.05).

Since the carbohydrate-protein group received a drink with fat

mixed in, and the carbohydrate group received fat supplements in

13 http://www.utexas.edu/education/kinesiology/exerphysio/ivy.html. Accessed 2-19-2004. Nutrition for Sports, Essentials of 70