Cardio
Condtioning
C
ON
DITIONE
DF
O
R
THE CHASE
MCCORMACKMICHAELWe all do 'cardio', but why?
Your heart is a ‘cardiac’ muscle at the centre of your
circulatory system. The cardiovascular system consists of a
network of blood vessels that carry blood and nutrients to (via the
arteries) and from (via the veins) all areas of your body. Your heart
is controlled by internal receptors that produce electrical signals
to contract and relax the heart. When the walls contract, blood is
pumped into your circulatory system.The facts
At rest, the cardiac output (total volume of blood pumped
out of the heart) is about 5 litres per minute. When the heart
is pumping at full force, the cardiac output reaches around 20-25
litres per minute.
During exercise, by-products from muscles (lactic acid, hydrogen
ions, carbon dioxide) in the blood stimulate the respiratory
centres in the brainstem to signal the respiratory muscles to
become more active. The primary respiratory muscles are the
diaphragm and external intercostals (the thin muscles between
each individual rib). All muscles that are attached to the ribcage
have the potential to cause a breathing action, including the chest
muscles, abdominals and upper neck.
Higher blood pressures during exercise increase the blood flow to
the lungs for oxygen exchange to take place. The ‘cardiovascular’
and ‘respiratory’ system work hand in hand. More oxygen in the
bloodstream and faster clearance rates of waste products from the
bloodstream results in better performance on the hill.How hard are we actually
working?
The RPE (rated perceived exertion) scale is a quick and
reliable method to gauge the intensity you are working at.
The RPE scale runs from 0-10. Perceived exertion is an individual's
self-rating of exercise intensity in relation to phrases on the scale.
As an example, if you had a self-rated RPE of 0, that might be how
you feel when sitting in a chair. Somewhere in the middle (an
RPE of 5/6) might be how you feel during a 30min steady state
jog. A self-rated 10 is how you would feel at the end of a maximal
exercise stress test. An RPE is relative to each person and situation.- Nothing at all
- Just noticeable
- Very light
- Light
- Moderate
- Somewhat heavy
6. Heavy
7. Very heavy
8. Very, very heavy
9. Close to maximum
10. Maximum exertion
Off season vs peak season
Let’s say you and your mate (who have different fitness
levels) are carrying the same weight, walking up the same
ridgeline, at the same pace on the way to camp. You might
have an RPE of 4 walking up that hill, so 40% maximum effort
in other words. On the other hand, your mate who enjoyed the
‘off season’ a bit too much may be working at an RPE of 7 or 8.74 NZ HUNTER MAGAZINE ~ August / September 2019How
To
Cardio
Condtioning
C
ON
DITIONE
DF
O
R
THE CHASE
MCCORMACKMICHAELWe all do 'cardio', but why?
Your heart is a ‘cardiac’ muscle at the centre of your
circulatory system. The cardiovascular system consists of a
network of blood vessels that carry blood and nutrients to (via the
arteries) and from (via the veins) all areas of your body. Your heart
is controlled by internal receptors that produce electrical signals
to contract and relax the heart. When the walls contract, blood is
pumped into your circulatory system.The facts
At rest, the cardiac output (total volume of blood pumped
out of the heart) is about 5 litres per minute. When the heart
is pumping at full force, the cardiac output reaches around 20-25
litres per minute.
During exercise, by-products from muscles (lactic acid, hydrogen
ions, carbon dioxide) in the blood stimulate the respiratory
centres in the brainstem to signal the respiratory muscles to
become more active. The primary respiratory muscles are the
diaphragm and external intercostals (the thin muscles between
each individual rib). All muscles that are attached to the ribcage
have the potential to cause a breathing action, including the chest
muscles, abdominals and upper neck.
Higher blood pressures during exercise increase the blood flow to
the lungs for oxygen exchange to take place. The ‘cardiovascular’
and ‘respiratory’ system work hand in hand. More oxygen in the
bloodstream and faster clearance rates of waste products from the
bloodstream results in better performance on the hill.How hard are we actually
working?
The RPE (rated perceived exertion) scale is a quick and
reliable method to gauge the intensity you are working at.
The RPE scale runs from 0-10. Perceived exertion is an individual's
self-rating of exercise intensity in relation to phrases on the scale.
As an example, if you had a self-rated RPE of 0, that might be how
you feel when sitting in a chair. Somewhere in the middle (an
RPE of 5/6) might be how you feel during a 30min steady state
jog. A self-rated 10 is how you would feel at the end of a maximal
exercise stress test. An RPE is relative to each person and situation.- Nothing at all
- Just noticeable
- Very light
- Light
- Moderate
- Somewhat heavy
6. Heavy
7. Very heavy
8. Very, very heavy
9. Close to maximum
10. Maximum exertion
Off season vs peak season
Let’s say you and your mate (who have different fitness
levels) are carrying the same weight, walking up the same
ridgeline, at the same pace on the way to camp. You might
have an RPE of 4 walking up that hill, so 40% maximum effort
in other words. On the other hand, your mate who enjoyed the
‘off season’ a bit too much may be working at an RPE of 7 or 8.74 NZ HUNTER MAGAZINE ~ August / September 2019
How
To