Jeff S' Volek, Ph'D', R'D'

1
Dietary manipulations to enhance adaptations to
strength training
Jeff S. Volek, Ph.D., R.D. Human Performance
Laboratory Department of Kinesiology University
of Connecticut Storrs, Connecticut USA

2
Paradigm
Diet is a powerful method to alter substrate and
hormone availability to skeletal muscle which
in turn affects metabolic processes and
adaptations to training.
3
Background

• Diet can alter events that impact acute responses
  to exercise and chronic adaptations to training
  by a variety of mechanisms
• Factors to consider nutrient quantity, quality,
  and timing
• Most research has focused on how diet affects the
  acute response to resistance exercise, with
  little work linking this to chronic adaptations

4
Intake of Macronutrients
Protein Carbohydrate Fat
5
ACUTE RESPONSE TO RESISTANCE EXERCISE
Nutrient hormonal uptake interact w/
contraction-induced mechanical chemical events
in muscle to regulate enzyme activity genes
Metabolic effects on carbohydrates, lipids, and
proteins can affect acute performance and chronic
adaptations
Alteration of nutrient and hormonal milieu in the
circulation
PATHWAY OF ADAPTATION
REPEATED ACUTE RESPONSES CHRONIC TRAINING
Volek et al. MSSE. 2004
6
Approach

• 1. Acute effects of carbohydrate, protein, and
  carbohydrate protein
• - Quantity
• - Quality
• - Timing
• - Digestion Rate
• 2. Acute effects of nutrients on hormonal
  responses to resistance exercise
• 3. Chronic effects of protein supplementation on
  adaptations to training
• 4. Effects of macronutrient manipulation
  maintaining muscle during weight loss

7
Protein Balance

• Resistance training alone ? ? protein synthesis
  and breakdown
• In the absence of nutritional intake, protein
  balance is still negative

Resting/Fasting
8
Carbohydrate After Resistance Exercise Favorably
Affects Protein Balance, But Still Remains
Negative
Placebo
Carb (100 g)
Borsheim et al. 2004
9
Amino Acids After Resistance Exercise Transiently
Increases Protein Balance
100
100
Phenylalanine Net Balance (nmol/min/100 mL leg)
50
50
0
0
-50
-50
2-3
3-4
2-3
3-4
0-1
1-2
0-1
1-2
Hours Postexercise
Hours Postexercise
Rasmussen et al. 2000
10
Only Essential Amino Acids (AA) Stimulate Protein
Synthesis After Resistance Exercise
6 g EAA 35 g CHO
125
100
75
6 g AA (3 g EAA) 35 g CHO
Protein Synthesis (net phenylalanine uptake
mg/h/leg)
50
25
0
Miller et al. 2003
Rasmussen et al. 2000
11
Effects of Glucose and Amino Acids After
Resistance Exercise are Additive

• Beverages provided 1 hr after resistance exercise

120
6 g AA (3 g EAA)
80
35 g Glucose
Net Phenylalanine Uptake (mg/3 hr/leg)
40
0
CHO
AA
Mix
Miller et al. 2003
12
Co-Ingestion of Protein and Leucine Stimulate
Protein Synthesis

• Beverages provided intermittently each 30 min
  post resistance exercise over 6 hr
• CHO 0.3 g/kg/hr (50 glucose/50 maltodextrin)
• CHO PRO Same amount of CHO 0.2 g/kg/hr whey
  protein hydrolysate
• CHO PRO Leucine Same amount of CHO and PRO
  0.1 g/kg/hr leucine

Koopman et al. 2004
13
Amino Acids Before Exercise Increases Protein
Balance More Than After Exercise
Post-Ex Drink
Pre-Ex Drink
200
150
Phenylalanine Net Balance (nmol/min/100 mL leg)
100
50
0
-50
2nd h
Exercise
1st h
Rest
Tipton et al. 2001
14
Protein Quality Slow and Fast Digesting Proteins
Whey Protein
Casein Protein

• Quick gastric emptying
• Rapid, but short-lived, large increase in plasma
  amino acids
• Large, rapid, transient increase in protein
  synthesis
• No effect on protein oxidation/breakdown

• Slow gastric emptying
• Sustained moderate increase in plasma amino acids
• Moderate, sustained increase in protein synthesis
• Moderate decrease in protein oxidation/breakdown

Net protein balance over several hours slightly
better with casein
15
Importance of Protein Digestion Rate

• Single meal of casein (30 g) slow-digesting
• Single meal of free amino acids same as casein
  (30 g) fast digesting
• Single meal whey (30 g) fast digesting
• Repeated meals of whey (30 g) to mimic casein
  (13 meals ea 20 min) slow digesting

• Fast meals induce strong, rapid, transient
  increase in plasma amino acids and oxidation
• Slow meals induce moderate increases in amino
  acids and oxidation, but a significant larger
  protein balance over 7 hr

Dangin et al. 2001
16
Protein Additional Considerations

• Stimulation of protein synthesis should not be
  the only method to evaluate protein needs
• Protein is most thermogenic nutrient
• Promotes inefficiency Metabolic Advantage
• Protein enhances satiety
• Protein impacts hormonal milieu

17
Approach

• 1. Acute effects of carbohydrate, protein, and
  carbohydrate protein
• - Quantity
• - Quality
• - Timing
• - Digestion Rate
• 2. Acute effects of nutrients on hormonal
  responses to resistance exercise
• 3. Chronic effects of protein supplementation on
  adaptations to training
• 4. Effects of macronutrient manipulation
  maintaining muscle during weight loss

18
Hormonal Regulation of Body Composition

Adipose Tissue Balance
Skeletal Muscle Balance
PRO Synthesis
Lipogenesis
TAG
FA
PRO
AA
PRO Breakdown
Lipolysis
19
Growth Hormone
Metabolic Effects
Response to Meals

• Promotes positive nitrogen balance by increasing
  protein synthesis, maybe inhibit protein
  degradation
• Partially mediated through stimulation of hepatic
  IGF-I
• Promotes lipolysis
• Inhibits lipogenesis
• Nutrient partitioning effects

• Response to food is quite variable
• Carbohydrate generally decreases GH
• Sensitive to glucose levels
• Hypoglycemia stimulates, hyperglycemia inhibits
  of GH
• Responsive to certain AA (arginine, lysine,
  ornithine)
• FA inhibit GH

20
35

• Protein-carbohydrate feeding enhances the GH
  response to whole body resistance exercise

30
25
20
15
10
5
0
Pre
0
15
30
45
60
Kraemer et al. J. Appl. Physiol. 851544-1555,
1998
21
Insulin

• Insulin promotes glucose uptake, glycogen
  formation, and protein synthesis (in presence of
  sufficient AA)
• Certain AA can ? insulin and there has been
  interest in combining protein and carbohydrate to
  maximize insulin secretion in hopes of enhancing
  post-exercise glycogen resynthesis and protein
  anabolism
• Protein and carbohydrate speeds glycogen
  resynthesis after prolonged submaximal cycling
  exercise compared to same amount of carbohydrate
  only, but no research with resistance exercise
• No benefit of protein if carbohydrate intake is
  very high (1.2 g/kg/hr)

22
1200
Day 1
Day 2
Day 3
1000
800
Insulin (pmol/L)
600
400
200
0
Pre
0
15
30
45
60
Pre
0
15
30
45
60
Pre
0
15
30
45
60
Kraemer et al. J. Appl. Physiol. 851544-1555,
1998
23
Insulin Regulation of Lipolysis
3

• Lipolysis is exquisitely sensitive to insulin
• The effect is virtually immediate
• Insulin also stimulates lipogenesis
• ? glucose uptake
• Activating lipogenic enzymes

2
Palmitate Flux
1
0
0
100
300
200
Insulin (pmol/L)
Jenson et al. Diabetes. 381591-1601, 1989
24
Testosterone

• Testosterone has potent anabolic effects on
  muscle tissue
• Feeding ? testosterone and the composition of
  meals, particularly the amount and type of fat,
  influences postprandial testosterone response
• Insulin testosterone tend to be inversely
  related but probably not cause and effect
• Similar to feeding, pre- and post-exercise meals
  consistently ? testosterone response to
  resistance exercise

25
800 kcal 1 FAT 26 PRO 73 CHO
Volek et al. Metabolism 501351-5, 2001
800 kcal 57 FAT 9 PRO 34 CHO
Metabolism 39943-6, 1990
26
30
25
Serum Testosterone (nmol/L)
20
15
Day 1
Day 2
Day 3
10
Pre
0
15
30
45
60
Pre
0
15
30
45
60
Pre
0
15
30
45
60
Kraemer et al. J. Appl. Physiol. 851544-1555,
1998
27
Decreased Testosterone

• Could be due to ? synthesis/secretion and/or ? in
  metabolic clearance
• ? testosterone not associated with ? LH
  suggesting a possible ? in testosterone uptake at
  the tissue level

28
Post-Exercise Shake or Placebo (Water)
8 kcal/kg 1.1 g Carbohydrate/kg 0.3 g
Protein/kg 0.25 g Fat/kg
Workout
Muscle Biopsy
Pre-EX
0 10 20 30 40
50 60
(min post-exercise)
Blood Draws
Kraemer et al., 2006
29
Androgen Receptor Band Intensity (AU)
Exercise
26
Water
24
PRO/CHO
22
20
18
Testosterone (nmol/L)
16
14
12
10
Pre
IP
10
20
30
40
50
60
Time After Exercise (min)
Kraemer et al., 2006
30
Cortisol

• Cortisol ? lipolysis and proteolysis to fuel
  gluconeogenesis to protect blood glucose and
  glycogen levels
• Postprandial responses must consider diurnal
  variation

75 g glucose
Reynolds et al. J Clin Endocrinol Metab.
861149-53, 2001
31
Effects of carbohydrate supplementation on
cortisol responses and adaptations to strength
training
26
Carbohydrate
Control
22
Cortisol (mg/dL)
18
14
Recovery
Exercise
10
0
20
40
60
80
100
120
Time (min)
Tarpenning et al., 2006
32
Type I
Type II
Tarpenning et al., 2006
33
Approach

• 1. Acute effects of carbohydrate, protein, and
  carbohydrate protein
• - Quantity
• - Quality
• - Timing
• - Digestion Rate
• 2. Acute effects of nutrients on hormonal
  responses to resistance exercise
• 3. Chronic effects of protein supplementation on
  adaptations to training
• 4. Effects of macronutrient manipulation
  maintaining muscle during weight loss

34
PRO-CHO Supplement More Effective Immediately
After Exercise than 2 h Post-Exercise in Elderly
Men During 12 wk Resistance Training
Esmarck et al., J. Physiol. 535301-311, 2001.
35
Protein Supplementation More Effective than
Carbohydrate for Enhancing Muscle Fiber
Hypertrophy

• 14 wk resistance training untrained men
• 25 g of carbohydrate or 25 g of protein (17 g
  whey, 3 g casein egg white glutamine)
• Provided 1 hr before and immediately after
  exercise

Anderson et al. 2005
36
Protein Supplementation More Effective than
Carbohydrate for Improving Anabolism and
Performance

• 10 wk resistance training untrained men
• 20 g of carbohydrate or 20 g of protein (14 g
  whey and casein 6 g AA)
• Provided 1 hr before and immediately after
  exercise
• Protein supplementation resulted in
• ? LBM (5.6 vs 2.7 kg)
• ? Thigh mass
• ? Muscle strength
• ? Serum IGF-1
• ? Muscle IGF-1 mRNA
• ? MHC I and IIa expression
• ? Myofibrillar protein expression

Willoughby et al. 2006
37
Approach

• 1. Acute effects of carbohydrate, protein, and
  carbohydrate protein
• - Quantity
• - Quality
• - Timing
• - Digestion Rate
• 2. Acute effects of nutrients on hormonal
  responses to resistance exercise
• 3. Chronic effects of protein supplementation on
  adaptations to training
• 4. Effects of macronutrient manipulation
  maintaining muscle during weight loss

38
Macronutrient Composition Strongly Affects Body
Composition

• Meta-regression 87 studies
• Low carbohydrate diets associated with greater
  weight loss percentage body fat
• High protein diets associated with better
  retention of fat-free mass
• Effects independent of energy intake

Krieger et al. Am J Clin Nutr 83260-74, 2006
39

• Diet Isocaloric 5 CHO, 60 FAT, 35 PRO
• Protein synthesis/proteolysis, plasma hormones,
  and muscle IGF mRNA at 2 and 7 d
• 24 h plasma insulin (? 50), GH and IGF-I (no ?),
  free IGF-I (? 30)
• 2-fold ? Muscle IGF-I mRNA
• 20 ? leucine Ra
• 2-fold ? muscle fractional synthetic rate

J Clin Endocrinol Metab. 905175-81, 2005.
40
A 6 wk Very Low Carbohydrate Diet Enhances Fat
Loss and Increases Lean Body Mass
P lt 0.05
P lt 0.05
P lt 0.05
BM FM FFM
Volek et al. Metabolism. 50(11)1351-1355, 2001.
41
Low-CHO
Low-Fat
-12
0
-2
-4
-6
8
-10
Weight Loss (kg)
42
0
-1
-2
-3
Whole Body Fat Loss (kg)
-4
-5
-6
0
-1
-2
Trunk Fat Loss (kg)
-3
Volek et al. Nutr Metab. 2004 Nov 81(1)13.
-4
Mid
Post
Pre
43
Low Carbohydrate/High Protein Diet and Resistance
Exercise Have Additive Effects on Body Composition

• 4 mo weight loss intervention
• Group
• Pro CHO
• Hi Pro 30 18
• Hi Carb 38 61

Layman et al J Nutr. 135(8)1903-10, 2005
44
2
1.8
0.2
0
-2
-3.5

• 3 mo weight loss intervention with low
  carbohydrate (LC) vs low fat (LF) with and
  without resistance exercise (RE).

-3.7
Change in Kilograms
-4
-2.0
-6.2
-6
-7.3
Fat Mass
-8
Lean Body Mass
-3.6
-10
LF
LC
LFRE
LCRE
Volek Unpublished
45
Muscle Glycogen and Metabolic Regulation

• Glycogen is not just a substrate for exercise
  metabolism
• Low muscle glycogen signals
• Translocation of GLUT4
• Glucose uptake
• ? AMPK
• Lipid oxidation
• Net protein degradation
• ? Branched-chain oxoacid dehydrogenase
• ? Glycogen synthase
• ? Rate of glycogen resynthesis
• ? Transcription rates and mRNA levels of
  metabolic genes

46
Chronic Low Carbohydrate Diet
Glycogen Tank
Carbohydrate
Protein
? GH ? IGF-I (muscle) ? Testosterone ? Insulin
TG Amino Acids
47
Short-Term High Carbohydrate
Glycogen Tank
Carbohydrate
Protein
? GH ? IGF-I (plasma, muscle) ? Testosterone ?
Insulin
Glucose Amino Acids
48
Chronic High Carbohydrate
Glycogen Tank
Carbohydrate
Protein
? GH ? IGF-I (muscle) ? Testosterone ? Insulin
Glucose Amino Acids
49
H
Creatine

• Over two dozen studies have reported that
  creatine supplementation enhances lean body mass
  and/or muscle strength responses to resistance
  training
• Could be due to several mechanisms
• ? lean body mass
• ? protein synthesis
• ? myosin heavy chain mRNA and protein
  expression
• ? expression of myogenic transcription factors
• ? satellite cell mitotic activity
• ? protein synthesis secondary to increased
  cellular swelling
• ? intensity of individual workouts
• ? muscle glycogen

50
Muscle Fiber Cross-Sectional Area
Creatine
1500
Placebo
1200
900
? Area (?m2)
600
300
0
I
IIA
IIB
IIAB
Volek et al. 1999
51
The Future

• One challenge in the future will be to match the
  varying nutritional demands associated with
  periodized resistance training programs with
  periodized diet strategies
• Ultimately, timing or cycling of diet on an
  hourly, daily, weekly, or monthly basis to match
  the unique demands of each workout or phase of
  training, may enhance adaptations to training
  over one single diet strategy

52
Summary

• Diet can influence pathway of adaptation and
  adaptations to resistance training
• Nutrient timing can alter energy substrates and
  the hormonal environment to favor anabolism
• Protein provided before and after exercise
  represents an easy an effective method to alter
  muscle protein balance