ENERGY FOR EXERCISE BS263

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ENERGY FOR EXERCISE BS263

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To review the contribution to energy production of the different ... 7 kg fat x 9 kcal.g-1 = 63,000 kcal 20 marathons or 30 days at rest. When is it engaged? ... – PowerPoint PPT presentation

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Title: ENERGY FOR EXERCISE BS263

1
ENERGY FOR EXERCISE BS263

LECTURE 3. Capacity of the Energy (Power)
systems.
AIMS.
To review the contribution to energy
production of the different energy (power)
systems during exercise of different intensities.
LEARNING OBJECTIVES.
After this section of the course you should be
able to do the following.
1. Explain the relative contributions of the
different energy systems to exercise of different
intensities and duration.

2
BACKGROUND READING.

McArdle, W.D., Katch, F.I. and Katch, V.L.
(2006). Exercise Physiology. (6th Edition)
Lippincott Williams and Wilkins. Baltimore.
Maughan, R. and Gleeson, M. (2004) The
Biochemical basis of Sports Performance. Chapters
1,3,4, 5, Oxford University Press
Gastin PB (2001), Energy system interaction and
relative contribution during maximal exercise.
Sports Medicine 31, (10), 725-741
Read this paper PDF in CMR

3
Capacity of the power systems.

Anaerobic alactic.
What is the capacity of this system?
5 mM ATP (MW 507), 15 mM CP (MW 211)
What would this be as mass in a 60 kg female?
Would last about 7 s (if max and exclusive).
When is it engaged?
Maximal intensity brief intermittent.
Temporal buffer.
How long to regenerate?
Half time about 1 min. at rest
(McCann et al., 1995)

4
Capacity of the power systems.

Anaerobic lactic.
What is the capacity of this system?
90 s (proton accumulation) 6 min (glycogen
depletion)
When is it engaged?
High intensity, short duration
Energy buffer during fast component of O2
kinetics.
Why does lactate accumulate?
Rate of production (of pyruvate) exceeds rate of
mitochondrial uptake and lactate shuttle
Blood lactate profiles. (Fig 7.2)

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Capacity of the power systems.

Aerobic.
What is the capacity of this system?
(Carbohydrate? Fat?).
Aerobic systems release more of the potential
energy that is present in macronutrients.
Glycogen gt90 min (500 g, 2000 kcal).
Lipid several days. 7 kg fat x 9 kcal.g-1
gt63,000 kcal gt20 marathons or gt30 days at rest.
When is it engaged?
The long term power system. Reflected by O2
kinetics. Maximal rate of energy production
(VO2max) limited by delivery (supply side
central limitations) and consumption (peripheral
limitations).
See Fig 7.3.

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Power system spectrum of exercise.

How does the spectrum of energy systems engaged
vary with intensity and duration of exercise?
Different activities (intensity/duration) engage
the power systems in characteristic proportions
at different stages in the activity.

9
Relative contribution of the energy systems in
brief maximal exercise.
10 s
30 s
90 sec
10
Absolute contribution of the energy systems in
brief maximal exercise.
11
Relative contribution of anaerobic and aerobic
energy systems in maximal exercise of different
durations.
12
Implications of the energy spectrum of exercise
for training.

Why is it helpful for athletes and their coaches
to be aware of the energy spectrum of their
event?
Specificity of training.
Are the energy systems cross-trainable? (Tanaka
and Swensen 1998)
To some extent.
What kind of training is appropriate for the
anaerobic alactic system?
High intensity intermittent brief (lt10 s) and
brief recovery.
What parameters might be susceptible to this kind
of training?
Fig 21.3, Table 21.4
What kind of training is appropriate for the
anaerobic lactic system?
High intensity, longer efforts (lt2 min) and
recovery.
What parameters might be susceptible to this kind
of training?

13
Potential for enhancement of capacity of
components of anaerobic power systems by
appropriate training.
14
Implications of the energy spectrum of exercise
for training.

What kind of training is appropriate for the
aerobic system?
LSD and threshold training.
What parameters might be susceptible to this kind
of training?
VO2max VO2max at LT.
Table 21.3.
Other than training the power systems, what are
the other expected outcomes of training?
Central and peripheral adaptations.
Patterns of motor recruitment.
Skills enhancement.