Bob Seebohar, MS, RD, CSSD, CSCS
USA Triathlon Level III Elite Coach
Sport Dietitian/Exercise Physiologist
Metabolic Testing for Endurance Athletes
Objectives
1) Describe principles of advanced metabolic testing and physiological monitoring.
2) Discuss how to improve performance with specific metabolic and physiological assessment and monitoring tools.
3) Customize performance nutrition plans for athletes based on individual physiological parameters.
Metabolic Calorie Efficiency Assessment
(MCEA)
How efficient is the body in utilizing CHO and FAT at different intensities and during
certain training cycles and how can these answers be utilized in practical
sports nutrition recommendations for athletes?
% VO2 max (intensity)
Car
bohy
drat
e (%
)
Fat (
%)
0 20 40 60 80 100
0
10
20
30
4
050
60
30
40
50
60
7
0
80
9
0
100
Crossover Concept
% VO2 max (intensity)
Car
bohy
drat
e (%
)
Fat (
%)
0 20 40 60 80 100
0
10
20
30
4
050
60
30
40
50
60
7
0
80
9
0
100
Improvement in Fitness =
% VO2 max (intensity)
Car
bohy
drat
e (%
)
Fat (
%)
0 20 40 60 80 100
0
10
20
30
4
050
60
30
40
50
60
7
0
80
9
0
100
Nutrition Periodization and Improved Fitness
MCEA Protocol• Measurement of gas exchange (O2 , CO2 )
• Metabolic cart with freedom of data manipulations
• %CHO, %FAT
• RER/RQ
• REE (Kcal/day)
• Sub-maximal exercise bout, 45-60 minutes
• Warm-up of 15-20 minutes on the cart
• No calories or stimulants for 2-4 hours prior
MCEA Protocol
• Bike with power measuring capabilities
• Treadmill (1-2% grade)
• Two methods:
1. Incremental (crossover point)
• Five minute stages
• Increase 15-25 (50 elite) watts or 0.2-0.4mph
2. Steady-state (competition nutrition planning)
• Continuous at predetermined power output, pace and/or HR
MCEA Overview• Markers
• RQ/RER start and increase
• Crossover point (0.85)
• Calorie use efficiency (%CHO, %FAT)
• RQ/RER >0.93, no need to continue in most cases in an incremental test
• RQ/RER may have to be maintained at >0.93 for steady state test
Data Sheet
MCEA Examples and Applications:
Incremental Workload
Run: Incremental
81%77% 75% 78% 78%
72%68%
61%
49%
20% 23% 26% 23% 23%28%
32%
52%
75%
26%
39%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Min/mile:14:16
13:20 12:30 11:46 11:07 10:31 10:00 9:32 9:05 8:42
Amateur Male Ironman Athlete
Conclusions
• Lower carbohydrate diet
• Good aerobic/cardiovascular system
• Very efficient in burning fat at higher intensities
Energy Expenditure Table
Pace Heart RateKcal
hour/min CHO (gr/cal) Fat (gr/cal)14:16 103 355/6 18/72 32/28813:20 128 495/8 28/114 42/37812:30 137 510/9 33/132 43/38711:46 143 528/9 30/120 46/41411:07 145 536/9 31/124 46/41410:31 153 578/10 38/152 48/43210:00 160 580/10 41/164 46/414
9:32 165 621/10 50/200 47/4239:05 171 650/11 63/252 44/3968:42 173 695/12 90/360 38/342
Energy Expenditure Table
Pace Heart RateKcal
hour/min CHO (gr/cal) Fat (gr/cal)14:16 103 355/6 18/72 32/28813:20 128 495/8 28/114 42/37812:30 137 510/9 33/132 43/38711:46 143 528/9 30/120 46/41411:07 145 536/9 31/124 46/41410:31 153 578/10 38/152 48/43210:00 160 580/10 41/164 46/414
9:32 165 621/10 50/200 47/4239:05 171 650/11 63/252 44/3968:42 173 695/12 90/360 38/342
Energy Expenditure Table
Pace Heart RateKcal
hour/min CHO (gr/cal) Fat (gr/cal)14:16 103 355/6 18/72 32/28813:20 128 495/8 28/114 42/37812:30 137 510/9 33/132 43/38711:46 143 528/9 30/120 46/41411:07 145 536/9 31/124 46/41410:31 153 578/10 38/152 48/43210:00 160 580/10 41/164 46/414
9:32 165 621/10 50/200 47/4239:05 171 650/11 63/252 44/3968:42 173 695/12 90/360 38/342
Energy Expenditure Table
Pace Heart RateKcal
hour/min CHO (gr/cal) Fat (gr/cal)14:16 103 355/6 18/72 32/28813:20 128 495/8 28/114 42/37812:30 137 510/9 33/132 43/38711:46 143 528/9 30/120 46/41411:07 145 536/9 31/124 46/41410:31 153 578/10 38/152 48/43210:00 160 580/10 41/164 46/414
9:32 165 621/10 50/200 47/4239:05 171 650/11 63/252 44/3968:42 173 695/12 90/360 38/342
Energy Expenditure Table
Pace Heart RateKcal
hour/min CHO (gr/cal) Fat (gr/cal)14:16 103 355/6 18/72 32/28813:20 128 495/8 28/114 42/37812:30 137 510/9 33/132 43/38711:46 143 528/9 30/120 46/41411:07 145 536/9 31/124 46/41410:31 153 578/10 38/152 48/43210:00 160 580/10 41/164 46/414
9:32 165 621/10 50/200 47/4239:05 171 650/11 63/252 44/3968:42 173 695/12 90/360 38/342
Nutrition Rx for Ironman Athlete
• Ironman EI is ~25-35% TEE
• Race intensity 65-75% max
• Emphasis on fat expenditure
and at what intensities this
is maximized to reduce
exogenous CHO feedings
• If bike nutrition was
adequate, safe to consume
~173-217 kcal/hr on the run
Pace HRKcal
hr/minCHO
(gr/cal)Fat
(gr/cal)14:16 103 355/6 18/72 32/28813:20 128 495/8 28/114 42/378
12:30 137 510/9 33/132 43/387
11:46 143 528/9 30/120 46/414
11:07 145 536/9 31/124 46/41410:31 153 578/10 38/152 48/432
10:00 160 580/10 41/164 46/414
9:32 165 621/10 50/200 47/4239:05 171 650/11 63/252 44/396
8:42 173 695/12 90/360 38/342
Bike: Incremental
45% 42% 40% 42% 45%41%
37% 37%
14%
55%59% 60% 59%
55%60% 63%
86%
44%
64%57%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Watts:100
125 150 175 200 225 250 275 300 325
Elite Female Short Course Triathlete
Conclusions
• Did not achieve a true crossover point
• Higher carbohydrate diet
• More efficient at burning fat at higher vs. lower
intensities
Energy Expenditure Table
Power Heart RateCalorie
hour/minCHO
(gr/cal) Fat (gr/cal)100 75 354/6 49/196 18/162125 83 465/8 69/276 22/198150 91 524/9 79/316 23/207175 101 602/10 89/356 28/252200 114 693/12 95/380 35/315225 122 821/14 117/468 40/360250 136 914/15 137/548 41/369275 155 1033/17 163/652 42/378300 169 1130/19 181/724 46/414325 183 1313/22 282/1128 20/180
Energy Expenditure Table
Power Heart RateCalorie
hour/minCHO
(gr/cal) Fat (gr/cal)100 75 354/6 49/196 18/162125 83 465/8 69/276 22/198150 91 524/9 79/316 23/207175 101 602/10 89/356 28/252200 114 693/12 95/380 35/315225 122 821/14 117/468 40/360250 136 914/15 137/548 41/369275 155 1033/17 163/652 42/378300 169 1130/19 181/724 46/414325 183 1313/22 282/1128 20/180
Energy Expenditure Table
Power Heart RateCalorie
hour/minCHO
(gr/cal) Fat (gr/cal)100 75 354/6 49/196 18/162125 83 465/8 69/276 22/198150 91 524/9 79/316 23/207175 101 602/10 89/356 28/252200 114 693/12 95/380 35/315225 122 821/14 117/468 40/360250 136 914/15 137/548 41/369275 155 1033/17 163/652 42/378300 169 1130/19 181/724 46/414325 183 1313/22 282/1128 20/180
Energy Expenditure Table
Power Heart RateCalorie
hour/min CHO (gr/cal) Fat (gr/cal)100 75 354/6 49/196 18/162125 83 465/8 69/276 22/198150 91 524/9 79/316 23/207175 101 602/10 89/356 28/252200 114 693/12 95/380 35/315225 122 821/14 117/468 40/360250 136 914/15 137/548 41/369275 155 1033/17 163/652 42/378300 169 1130/19 181/724 46/414325 183 1313/22 282/1128 20/180
Nutrition Rx Female SC Triathlete
Power HRCalorie hr/min
CHO (gr/cal)
Fat (gr/cal)
100 75 354/6 49/196 18/162
125 83 465/8 69/276 22/198
150 91 524/9 79/316 23/207
175 101 602/10 89/356 28/252
200 114 693/12 95/380 35/315
225 122 821/14 117/468 40/360
250 136 914/15 137/548 41/369
275 155 1033/17 163/652 42/378
300 169 1130/19 181/724 46/414
325 183 1313/22 282/118 20/180
• Race intensity >85% max
• Race EI is ~15-25% of
race TEE
• Emphasis on CHO expenditure
and exogenous CHO feedings
• Fat expenditure less important
• Consume minimum only:
~137-170 kcal/hr on the bike
MCEA Examples and Applications:
Constant Workload
Constant Workload: Month 1
Bike: Competitive Amateur Cyclist
33%24%
34% 31% 30% 33% 40% 36% 36%
74%64% 67% 69% 65% 58% 63%65%
63%
0%
4 4 4 4 5 5 5 5 5
250 250 250 250 250 250 250 250 250
1117 1126 1127 1132 1128 1130 1120 1091 1103
149 152 153 154 154 157 155 156 156
CH
O (b
lack
) and
Fat
(red
)
RPE
Watts
Total Kcals
Heart Rate
33%
24%
34%31% 30%
33%40%
36% 36%
65%
74%
64% 67% 69%65%
58%63% 63%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
250 250 250 250 250 250 250 250 250
Power (Watts)
Perc
ent C
ontr
ibut
ion
from
CH
O a
nd fa
ts to
TEE
Interpretation of Data
Average CHO
Expend.(cal/hr)
Average HR
(bpm)
Average power (watts)
Average CHO
oxidation (%)
Average Fat
oxidation (%)
731 154 250 65 33
Constant Workload: Month 2
44% 46% 47% 47% 53% 48% 52% 50% 53%
52% 52% 51% 46% 51% 46% 46%55%
49%
0%
4 4 4 5 5 5 5 5 5
250 250 250 250 250 250 250 250 250
1220 1187 1192 1170 1189 1187 1171 1157 1154
141 138 140 139 140 140 140 140 142
CH
O (b
lack
) and
Fat
(red
)
RPE
Watts
Total Kcals
Heart Rate
44% 46% 47% 47%53%
48%52% 50%
53%
55% 52% 52% 51%46%
51%46% 49% 46%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
250 250 250 250 250 250 250 250 250
Power (Watts)
Perc
ent C
ontri
butio
n fro
m C
HO
and
fats
to T
EE
Interpretation of DataAverage
CHOexpend.(cal/hr)
Average HR
(bpm)
Average power (watts)
Average CHO
oxidation (%)
Average Fat
oxidation (%)
588(-143)
140(-14)
250 50(-15)
49(+16)
• In one month emphasizing aerobic, heart rate based training, athlete increased utilization of fats as energy.
• Athlete was able to decrease reliance of CHO per hour, thus the need for exogenous CHO was reduced.
Application
1. Athlete can appropriately determine caloric expenditure based on heart rate and/or power/pace training zones.
2. Athlete can appropriately determine total calorie and exogenous CHO needs per hour for each training zone.
MCEA Case Study
• Male endurance athlete
• Training for 100 mile run
• Goal to finish under 30 hour cut-off
• Trains with a heart rate monitor
• Knows lactate clearing efficiency (aka- lactate threshold) heart rate and pace zones
26%30%
34%26%
18%
8%
74%70%
66%74%
83%
93%
11%
90%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Min/mile:10:00
9:32 9:05 8:42 8:20 8:00 7:42
End of Transition Cycle
Dietary CHO: 7.7 g/kg (61%)
Month 1
3 months later
45%50%
42%46% 44%
30%
55% 58%54% 56%
42%50%
70%
58%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Min/mile: 10:00 9:32 9:05 8:42 8:20 8:00 7:42
End of Preparation cycle
Dietary CHO: 5.4 g/kg (53%)
MCEA Case Study Summary
Pace (min/mile)
CHO Expend.Month 1
CHO Expend.Month 3
FAT Oxidation Month 1
FAT Oxidation Month 3
10:00 74 55 26 45
9:32 70 50 30 50
9:05 66 58 34 42
8:42 74 54 26 468:20 83 56 18 44
8:00 90 58 11 42
7:42 93 70 8 30
MCEA Case Study Summary
Pace (min/mile)
CHO Expend.Month 1
CHO Expend.Month 3
FAT Expend. Month 1
FAT Expend. Month 3
10:00 74 55 26 45
9:32 70 50 30 50
9:05 66 58 34 42
8:42 74 54 26 468:20 83 56 18 44
8:00 90 58 11 42
7:42 93 70 8 30
Underdeveloped aerobic system
Higher CHO diet at less appropriate times of year
Poor utilization of body fat stores for energy
More reliance on supplemental CHO
Inability to properly feed during training/racing
Application
Want More Proof? Male Elite Cyclist
3 weeks later
0
50
100
1 2 3 4 5
Stages
Perc
enta
ge
Start
0
50
100
1 2 3 4 5
Stages
Perc
enta
ge
Future Looks Bright!
1. MCEA will allow athletes to further individualize nutritional needs for competition.
2. Calorie and carbohydrate intake can be matched for specific heart rate and power/pace training zones.
3. Crossover Concept can be utilized to gauge fitness in addition to it allowing an athlete to manipulate nutrition needs based on fitness throughout the year.
• A good coach understands the “why.”
• Over-testing is as bad as under-testing.
• Coaching is as much an art as it is a science.
• Know how to apply science but don’t get bogged down with it. Listening to your athletes and observing them gives more information and feedback.
Summary
Great Resource!!!
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