KIN202 Lecture 7: Unit 5 Progressive Exercise Part 1
20 Jan 2019
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KIN 202 Unit 5 Progressive Exercise Part 1
Progressive Exercise Test OR Incremental Exercise Test OR Graded Exercise Test (GXT)
- Are protocols that possess a systematic and linear increase in exercise intensity of a
defined period of time until the individual is unable to maintain or tolerate the
workload
- Majority of protocols were developed for treadmills or bikes
- Step model
- Ramp model consist of a smooth increase in work load over a given period of time.
Typical ramps range from 20-50W per minute.
Determining VO2 Max
- VO2 max
• Maximum ability of the respiratory and cardiovascular systems to take up O2
from the atmosphere, deliver the O2 to the muscles and for the mitochondria
to utilize the O2 to produce ATP
• Graphical definition: occurs when there is a plateau or no further increase in
VO2 despite an increase in WR
o Definition of a plateau: an increase in VO2 of less or equal to 150
mL/min with an increase in WR
- Secondary criteria indicating a successful max test
• Volitional fatigue – the feeling that you absolutely cannot continue to do the
exercise
• Blood lactate – quite variable (depends on the individual)
• Achieving HRmax – HRmax = 220 – age = 208 – (0.7 x age)
• RPE greater or equal to 17 (BORG 6-20 scale)
• RER greater or equal to 1.15
• Achieving a plateau in VO2 is not seen in every test (less than 20% of the time);
sometimes it occurs 100% of the time – depends on participants
VO2 max Values Attained On A Treadmill Tend To Be Greater Than A Bike
- 20% greater than that observed on a cycle ergometer
- Why?
• Greater muscle mass active while running (postural, arm)
• Greater Cardiac output
• Larger (a-v)O2
• Greater vascular conductance (blood flow normalized to mean arterial pressure)
Force Production During Progressive Exercise
- During a GXT, the WR goes up every 2 mins, and when WR increases, it gets harder
to push the pedals
- What must our muscle do to push against the higher resistance on the pedals?
• Generate more force
- How do we generate more force?
• Recruit more motor units
• Increase the AP frequency
- What does EMG measure?
• Muscle AP (directly proportional to WR and gives a linear graph indicating a
progressive increase in muscle activation)
- ATP demand is also directly proportional to WR
Substrate Utilization During Progressive Exercise: The Crossover Concept
- As exercise intensity increases, there is an increase in CHO oxidation and decrease in
FFA oxidation
1. Recruitment of fast Type II fibres
• Type II fibres have more glycolytic enzymes and fewer mitochondria and
lipolytic enzymes (responsible for fat breakdown)
2. Increasing blood levels of epinephrine
• Increases phosphorylase
• Causes an increase in muscle glycogen breakdown
• Results in an increased rate glycolysis and lactate production
• Increased [La- + H+] inhibits lipases by reducing the rate of lipolysis
• That reduces FFA delivery to skeletal muscle
• Decrease in blood flow to adipose tissue
Document Summary
Kin 202 unit 5 progressive exercise part 1. Progressive exercise test or incremental exercise test or graded exercise test (gxt) Are protocols that possess a systematic and linear increase in exercise intensity of a defined period of time until the individual is unable to maintain or tolerate the workload. Majority of protocols were developed for treadmills or bikes. Ramp model consist of a smooth increase in work load over a given period of time. Vo2 despite an increase in wr: definition of a plateau: an increase in vo2 of less or equal to 150 ml/min with an increase in wr. Vo2 max values attained on a treadmill tend to be greater than a bike. 20% greater than that observed on a cycle ergometer. Why: greater muscle mass active while running (postural, arm, greater cardiac output, larger (a-v)o2, greater vascular conductance (blood flow normalized to mean arterial pressure)
