- 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.”
- Dr. John Seifert, Professor of Exercise Physiology, Human
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