Chap. 4: Nutrition for Muscle Development

2300-3500 kcal to build one pound of muscle.

Goals of nutrition for resistance training:

“Nutrition influences recovery and workout intensity.”

Muscle Metabolism

Muscle proteins are remodeling on a regular basis, building (anabolism), breakdown (catabolism), and maintenance of tissue.
Protein synthesis occurs when energy demands are adequate to support stimulus for muscle growth.
Protein is generally spared as a source for energy production.
Acute response of protein synthesis:
- Short time after training
- Changes in protein balance
- Glycogen degradation or synthesis
Chronic responses:
- Increase in muscle size
- Increase in muscle strength
“Protein requirements decrease as we approach genetic limit.”
Overall goals:
- Net positive protein balance
- Muscle is in an anabolic state

Hormones = Chemical Messengers

Fuel selection.
Partitioning of nutrients.
Gene regulation.
Affect body composition and muscle mass.
Exercise increases blood flow, increases delivery of hormones and nutrients to cell.
Insulin:
- Released by pancreas due to high levels of blood glucose.
- Promotes glucose and amino acid uptake by tissue, glycogen formation and protein synthesis (probably) w/ enough amino acids.
Growth Hormone:
- Secreted by pituitary gland due to exercise, sleep, stress, low plasma glucose.
- Helps muscle cells take in amino acids.
- Decreases w/ aging.
- Increase in protein synthesis, fat metabolism, and glucose conservation.
- Hypoglycemia will stimulate increase in GH, circulating fatty acids decrease.
- GH is elevated for 30 minutes following exercise - anaerobic glycolysis.
Insulin-like Growth Factor:
- Anabolic hormone produced in liver and skeletal muscle w/ GH in blood stream.
- Regulates insulin metabolism, stimulates the growth of tissues, and assists.