PROTEIN
The question of how much protein an athlete should consume has been
researched and debated for years. In the early part of this century,
studies indicated that carbohydrate and lipids were the most important
exercise fuels and that exercise had little effect on protein needs.
Recent data with new experimental technology has determined that dietary
protein needs may increase with regular exercise. Exercise-induced
increased protein requirements may be a:
1. direct result of changes
in metabolism
2. an indirect result of insufficient calorie
intake
Factors that play a role in determining how much protein is used during
an exercise session:
1. Type of exercise
4. Duration of exercise
2. Frequency of exercise
5. Whether one is exercise
trained
3. Intensity of exercise
6. Environmental conditions
7. Energy content of diet
Type of Exercise
Endurance exercise require more protein to repair damaged muscle fibers
and provide additional calories. Strength exercises require more
calories to maintain muscle tissue and provide for additional growth. If
these additional calories are not provided protein eaten will be used as
am immediate energy source and decreases in muscle mass and strength may
occur.
Frequency of Exercise
Too frequent training leads to reduced gains or even decreases in muscle
mass and strength.
Intensity of Exercise
When the intensity of the activity is increased the amount of protein
used is also increased.
Duration of Exercise
Exercise greater than 60 minutes increases protein breakdown due to a
decrease in carbohydrate fuel, which will cause the body to relie more
heavily on protein fuel.
Exercise Trained or Untrained
Protein needs may increase during the first 10 days of starting an
exercise program while the body is adapting to the changes. After 2-3
weeks of daily exercise these needs will return to normal.
Environmental Conditions Both internal and external envirnmental
conditional influence protein needs
Energy Content of the Diet
Calorie (energy) needs must be met to spare the breakdown of muscle
tissue. If too few calories are consumed the athlete may experience a
decrease in muscle mass and strength.
PROTEIN REQUIREMENTS
Endurance athletes should consume 12-15% of their total calories from
protein. Protein needs can be calculated by multiplying 1.0- 1.4 grams
of protein per kilogram body weight (refer to the following chart
calculations) Strength athletes with short bouts of extreme intensity use
mostly carbohydrate for fuel. Protein should also provide 12-15% of
their total calories.
Dangers of excessive protein
Increase stress on the liver and kidney
Increase amonia and urea levels (toxicity levels increase)
* Increase fluid needs- greater potential for dehydration
Increase nitrogen residuals- nitrogen by products are toxic and less
glyocen can be stored when there is excess protein.
* Metabolism of protein requires more water than carbohydrate or fat. As
dietary protein increases, water intake is recommended to minimize
dehydration effects.
Caution: if high levels of protein are being used be sure to increase
fluid.
Protein supplementation
Amino acids continuously breakdown and resythesize.
are oxidized for energy or stored as fat.
Excess amino acids
DO I EAT ENOUGH PROTEIN?
Protein needs vary between individuals based on body size, activity
level, and age. Protein needs may increase directly as a result of
changes in metabolism or indirectly as a result of insufficient calories
in the diet.
Body
Wt
Body
PROTEIN NEEDS PER KILOGRAM BODY WEIGHT
Wt
DAILY PROTEIN NEEDS
measured in grams
Body
Wt
(lbs)
95
100
105
110
115
120
125
130
135
140
145
150
155
160
165
170
175
180
185
190
195
200
205
210
215
220
225
230
235
240
245
Body
.8
1
1.2
1.4
1.5
1.6
35
36
38
40
42
44
45
47
49
51
53
54
56
57
60
62
64
66
67
69
71
73
74
76
78
80
82
84
86
87
89
43
45
48
50
52
55
57
59
61
64
66
68
70
71
75
77
80
82
84
86
89
91
93
95
98
100
102
105
107
109
111
52
54
58
60
62
66
68
71
73
77
79
82
84
85
90
92
96
98
101
103
107
109
112
114
118
120
122
126
128
131
133
60
63
67
70
73
77
80
83
85
90
92
95
98
99
105
108
112
115
118
120
125
127
130
133
137
140
143
147
150
153
155
65
68
72
75
78
83
86
89
92
96
99
102
105
107
113
116
120
123
126
129
134
137
140
143
147
150
153
158
161
164
167
69
72
77
80
83
88
91
94
98
102
106
109
112
114
120
123
128
131
134
138
142
146
149
152
157
160
163
168
171
174
178
Wt
(kg)
43
45
48
50
52
55
57
59
61
64
66
68
70
71
75
77
80
82
84
86
89
91
93
95
98
100
102
105
107
109
111