PDHPE
How does training affect performance?
Energy systems
● Role of energy systems: The transformation of food (chemical energy) → energy that
the muscles can use (mechanical energy)
● Digestion of food → sugars, amino acids and fatty acids
● From these, ATP (Adenosine triphosphate) is produced
● ATP is a high energy compound that stores and transfers energy to body cells,
allowing them to perform their specialised functions i.e. muscle contractions
● Role of ATP: Enables the release of energy from fuel (in the form of carbohydrates,
fats and protein)
● Structure of ATP: Consists of a large molecule called Adenosine (A) and 3 smaller
molecules called phosphates (P) ← Held together by high energy bonds
- When the last phosphate is detached, energy stored in bonds between the
phosphates becomes available → cells
1
, - ADP <> waste product that is discharged from
body
- It has the ability to quickly resynthesise → allowing us to continue to function while still
using the limited amount we have.
- Three systems that make ATP available are:
- Alactacid system (ATP/PC) ← anaerobic (not require O2 for the resynthesis of
ATP)
- How it works:
- An explosive movement causes the ATP molecule to split,
providing energy for muscular contraction
- Further muscular work relies on CP breaking down to creatine
and phosphate, and releasing energy
- The energy is used to drive free phosphate back to ADP to
form ATP.
- Once ATP forms, it can break down again - process repeats
- Lactic acid system ← anaerobic (not require O2 for the resynthesis of ATP)
- How it works:
2
, - Breaks down glycogen or glucose through glycolysis
- Lactic acid is produced because insufficient O2 results in the
partial breakdown of glucose, providing quick but limited ATP
production + by-product of Lactic acid
- Lactic acid levels continue to rise as intensity increases
- Aerobic system ← O2 dependent
- How it works
- Physical activity lasting >few minutes requires O2
- O2 gradually becomes available as the O2-rich blood fills the
muscle cells.
- Aerobic metabolism to break down glucose and fat (sometimes
protein) to produce ATP.
- Lactic acid does not accumulate because O2 is present
3
, Alactacid (ATP/PC) Lactic Acid Aerobic
source of fuel Creatine Phosphate Glycogen Carbohydrate, fat
and protein
broken down,
producing ATP &
energy for muscular
contraction.
efficiency of ATP Rapidly supplies Rapidly supplies Extremely efficient
production ATP. ATP, but requires (enables the
large amounts of production of much
more energy from
Very efficient in glucose.
glycogen → allowing
short, explosive us to work for longer
movements (i.e. periods)
weight lifting, discus
throwing)
Optimal for repeated
explosive activities
with a rest period →
for example, long
jumpers and weight
lifters.
duration that the After hard work: Depends on Virtually unlimited,
system can 2 seconds: ATP intensity; near at low intensities.
operate supplies are maximal effort = 30 (main system for
exhausted seconds, 70-80% = extended
3-4 minutes endurance events
10-15: CP supplies such as a marathon)
exhausted (fully Dominant system for
restored within 2 all maximal activity
performed between
minutes at rest )
30 - 2 minutes → e.g.
200 meter sprint or
freestyle
cause of fatigue Inability of the Build up of lactic Depletion of
system to acid within muscle glycogen stores in
continually cells. blood and liver, fat
resynthesise ATP stores, then proteins
from CP because CP stored in muscles.
supplies are quickly
exhausted.
4
How does training affect performance?
Energy systems
● Role of energy systems: The transformation of food (chemical energy) → energy that
the muscles can use (mechanical energy)
● Digestion of food → sugars, amino acids and fatty acids
● From these, ATP (Adenosine triphosphate) is produced
● ATP is a high energy compound that stores and transfers energy to body cells,
allowing them to perform their specialised functions i.e. muscle contractions
● Role of ATP: Enables the release of energy from fuel (in the form of carbohydrates,
fats and protein)
● Structure of ATP: Consists of a large molecule called Adenosine (A) and 3 smaller
molecules called phosphates (P) ← Held together by high energy bonds
- When the last phosphate is detached, energy stored in bonds between the
phosphates becomes available → cells
1
, - ADP <> waste product that is discharged from
body
- It has the ability to quickly resynthesise → allowing us to continue to function while still
using the limited amount we have.
- Three systems that make ATP available are:
- Alactacid system (ATP/PC) ← anaerobic (not require O2 for the resynthesis of
ATP)
- How it works:
- An explosive movement causes the ATP molecule to split,
providing energy for muscular contraction
- Further muscular work relies on CP breaking down to creatine
and phosphate, and releasing energy
- The energy is used to drive free phosphate back to ADP to
form ATP.
- Once ATP forms, it can break down again - process repeats
- Lactic acid system ← anaerobic (not require O2 for the resynthesis of ATP)
- How it works:
2
, - Breaks down glycogen or glucose through glycolysis
- Lactic acid is produced because insufficient O2 results in the
partial breakdown of glucose, providing quick but limited ATP
production + by-product of Lactic acid
- Lactic acid levels continue to rise as intensity increases
- Aerobic system ← O2 dependent
- How it works
- Physical activity lasting >few minutes requires O2
- O2 gradually becomes available as the O2-rich blood fills the
muscle cells.
- Aerobic metabolism to break down glucose and fat (sometimes
protein) to produce ATP.
- Lactic acid does not accumulate because O2 is present
3
, Alactacid (ATP/PC) Lactic Acid Aerobic
source of fuel Creatine Phosphate Glycogen Carbohydrate, fat
and protein
broken down,
producing ATP &
energy for muscular
contraction.
efficiency of ATP Rapidly supplies Rapidly supplies Extremely efficient
production ATP. ATP, but requires (enables the
large amounts of production of much
more energy from
Very efficient in glucose.
glycogen → allowing
short, explosive us to work for longer
movements (i.e. periods)
weight lifting, discus
throwing)
Optimal for repeated
explosive activities
with a rest period →
for example, long
jumpers and weight
lifters.
duration that the After hard work: Depends on Virtually unlimited,
system can 2 seconds: ATP intensity; near at low intensities.
operate supplies are maximal effort = 30 (main system for
exhausted seconds, 70-80% = extended
3-4 minutes endurance events
10-15: CP supplies such as a marathon)
exhausted (fully Dominant system for
restored within 2 all maximal activity
performed between
minutes at rest )
30 - 2 minutes → e.g.
200 meter sprint or
freestyle
cause of fatigue Inability of the Build up of lactic Depletion of
system to acid within muscle glycogen stores in
continually cells. blood and liver, fat
resynthesise ATP stores, then proteins
from CP because CP stored in muscles.
supplies are quickly
exhausted.
4
