Post workout carbs need essential amino acids to boost IGF-1

[Arnold]

Post workout carbs need essential amino acids to boost IGF-1
by Anthony Roberts

Summer is in full swing and that means scholastic athletes are getting back on the field in preparation for Autumn sports. After a workout, lots of these guys and gals turn to a so-called rehydration drink (perhaps the popular one that comes in the electric yellow/green color). But they???re not doing themselves any favors by slamming back a bunch of carbs unless they???re also putting down some essential amino acids (EAA). Because although growth hormone is elevated after training, with or without ingesting EAA, Insulin-like Growth Factor -1 (IGF-1) is only elevated with the addition of the essential aminos. Growth hormone on its own may not be as anabolic as once thought, and the most recent data would indicate that the majority of its anabolic effects are either directly caused, or at least mediated, by IGF-1.

Amino Acids. 2011 Feb 4. [Epub ahead of print]

Acute regulation of IGF-I by alterations in post-exercise macronutrients.

Foster EB, Fisher G, Sartin JL, Elsasser TH, Wu G, Cowan W, Pascoe DD.
Source

Department of Kinesiology, Auburn University, Auburn, AL, USA, ebyronf1@gmail.com.

Abstract

This investigation sought to examine the contributions of exercise and nutrient replenishment on in vivo regulation of the insulin-like growth factor-I (IGF-I) axis components. Eight college-aged males completed three high-intensity interval training (HIIT) protocols followed by three post-exercise nutritional protocols: (1) placebo (EX); (2) carbohydrate only (CHO); and (3) essential amino acid/carbohydrate (EAA/CHO). Samples were analyzed for growth hormone (GH), free IGF-I, IGFBP-1, IGFBP-2, insulin, hematocrit, hemoglobin, serum leucine, matrix metalloproteinase-9 (MMP-9) proteolytic activity, and presence of IGFBP-3 protease activity. No evidence for IGFBP-3 proteolysis was observed. Significant increases in [free IGF-I] and [leucine] were observed in the EAA/CHO group only. Significant differences were noted in [IGFBP-1] and [IGFBP-2] across conditions. Significant increases in [GH] and MMP-9 activity were observed in all groups. These results indicate that post-exercise macronutrient ratio is a determinant of [free IGF-I], [IGFBP-1 and -2] and may play a role in modulating the IGF-I axis in vivo.

Post workout carbs need essential amino acids to boost IGF-1 | Anthony Roberts Blog