Determining aerobic fitness is an essential part of fitness assessment. It provides insight into an individual’s level of cardiovascular fitness by measuring how efficient the heart is at pumping oxygenated blood to the body during exercise. Direct testing of oxygen uptake can be measured using a gas analysis system. Although predictive testing of oxygen uptake is more widely used; the equipment is more easily accessible, more cost efficient and will still provide valid results. The Modified Canadian Aerobic Fitness Test (mCAFT) is a step test used to determine about 85% of the age-predicted maximal heart rate. A linear relationship between heart rate and oxygen uptake is used to predict 100% maximal oxygen uptake from the results. The participant should continue stepping until they reach their ceiling heart rate (85%HRmax), or they experience intolerance, chest pain, facial pallor, laboured breathing, loss of coordination, dizziness, nausea, unable to maintain cadence or extreme leg pain in which case they should lay down in supine position with their legs elevated and their heart rate and blood pressure monitored. The rate of oxygen uptake can be described in L/kg however during training situations it is more useful to relate oxygen uptake relative to body weight in which case it will be described in mL/(kg x min).
The aerobic fitness uses an equation involving the participant’s body mass, age and the oxygen cost from the last stage of the test to determine their CPAFLA health benefit zone. Categorizing your client into health benefit zones is useful for a trainer as a guide for discussing fitness goals with their client. It can be a baseline measurement used to motivate the client to see their desired change. It is a great way to measure improvement before and after the exercise program.
Starting Stage by Age and Gender
|
Starting Stage |
||
| Age | Males | Females |
| 60-59 |
1 |
1 |
| 50-59 |
2 |
1 |
| 40-49 |
3 |
2 |
| 30-39 |
3 |
3 |
| 20-29 |
4 |
3* |
| 15-19 |
4 |
3 |
| Resting HR: | Resting BP: 110/65 mmHg | ||
| Age: 20 years | Gender: F | Body Mass: 59 kg | |
| 85% predicated HRmax: 170 bpm | 85% predicated HRmax: 28 b/10 sec | ||
|
Starting Stage Number |
HR (b/10 sec) |
HR (bpm) |
|
|
1st stage |
|||
|
2nd stage |
|||
|
3rd stage |
17 |
102 |
|
|
4th stage |
21 |
126 |
|
|
5th stage |
21 |
126 |
|
|
6th stage |
22 |
132 |
|
|
7th stage |
24 |
144 |
|
|
8th stage |
25 |
150 |
|
Post-Test Measurements
|
Time (min) |
HR (bpm) |
BP (mm/Hg) |
|
1 |
150 |
128/68 |
|
3 |
104 |
125/68 |
|
5 |
86 |
123/68 |
Aerobic Fitness
Score = 10 x [17.2 + (1.29 x O2 cost of the last completed stage) – (0.09 x body mass) – (0.18 x age)]
= 10 x [17.2 + (1.29 x 36.2) – (0.09 x 59) – (0.18 x 20)]
= 10 x [17.2 + (46.7) – (5.3) – (3.6)]
= 10 x (55.0)
= 550 mLkg-1min-1
Follow