Energy system interplay

Question 1

During exercise, does one energy system usually dominate?

Answer 1

During exercise all three systems combine to produce energy required for ATP resynthesis. However, one energy system typically dominates in producing the majority of energy.

Question 2

What determines the relative contribution of each energy system?

Answer 2

• The intensity of effort
  -The duration of effort
  -The availability and supply of oxygen to muscles
  -The type of effort (continuous or intermittent)
• The availability of fuels – CP, carbohydrates, fat, or protein.
• the individual’s fitness status.

Question 3

What are examples of continuous activities that require maximal effort from the start?

Answer 3

Events like 50 m freestyle, all field events in athletics, and a 500 m sprint cycle require maximal effort from the start, even though they vary in duration.

Question 4

What are examples of continuous activities that require sub-maximal effort from the start?

Answer 4

Events like the 1500 m, marathon, and school cross-country require sub-maximal effort from the start.

Question 5

guide for any interplay questions?

Answer 5

all 3 systems contribute simultaneously, but in different amounts depending on various factors.
INTERPLAY-
Intensity
Numbers and data
Time – the duration of effort versus the duration of the event.
Energy – ATP production and release
Rate
PC – Finite, but never totally depleted. Restored during rest.
Lactate and H+ accumulation (anaerobic glycolysis). Finite due to O2 deficit
Aerobic – increased contribution as duration increases. Requires O2 supply to meet O2 demand in continuous activity. In intermittent activity O2 supply restores CP and contributes to H+ oxidation.
Yield

Question 6

What do intermittent activities allow in terms of energy system recovery?

Answer 6

They allow CP (creatine phosphate) restoration during rest periods.

Question 7

How does rest duration affect CP restoration in intermittent activities?

Answer 7

The longer the rest, the more CP can be restored and reused for high-intensity efforts.

Question 8

What happens to oxygen supply during intermittent activity rest?

Answer 8

Oxygen supply can meet the decreased demand and begin oxidising accumulated H+.

Question 9

Is H+ removal as quick as CP restoration during intermittent activity rest?

Answer 9

No, H+ removal takes much longer—about 20 minutes for 50% removal.

Question 10

Which energy systems are dominant at maximal intensity and why?

Answer 10

Anaerobic systems, because the body cannot supply oxygen quickly enough to meet energy demands.

Question 11

What happens when intensity exceeds the lactate inflection point (LIP)?

Answer 11

Anaerobic systems are used, typically when heart rate exceeds 85% of maximum.

Question 12

Why can’t high-intensity efforts be sustained for long periods?

Answer 12

Due to CP depletion and the accumulation of H+ (hydrogen ions)

Question 13

When is the aerobic energy system the major ATP producer?

Answer 13

When intensity is at or just below the lactate inflection point (LIP).

Question 14

How does exercise duration affect energy system contribution?

Answer 14

The longer the activity, the more the body can supply oxygen, increasing the contribution of the aerobic system.