Peak Performance in Sport Practical 2
Measuring Power in the Laboratory
Learning Objectives:
By the end of this session you will:

Be able to collect a sample of capillary blood from the fingertip and measure glucose
and lactate concentration using the Biosen Analyser;

Discuss the expected values of glucose and lactate at rest, following ingestion of
carbohydrate and following high-intensity exercise.
Overview of Practical

Step 1: Overview and safety procedures

Step 2: Collection of capillary blood

Step 3: Effects of carbohydrates

Step 4: Effects of high-intensity exercise
Capillary Blood Glucose/Lactate
Measurements of glucose and lactate can provide an indirect measurement of the relative
exercise intensity and also about the metabolic pathways being utilised to generate energy.
1. If you are collecting a sample of blood, you MUST wear a pair of plastic gloves to
protect from any cross-contamination.
2. Thoroughly cleanse the middle or ring finger of your subject’s left hand using an
alcohol swab.
3. Remove the cap from a sterile lancet and place the tip on the end of your subject’s
finger (on the fleshy part away from the centre).
4. Press firmly downwards on the end of the lancet to puncture the skin in one quick,
steady motion.
5. Wipe the first drop of blood away from the finger.
6. Begin to collect blood in the capillary tube as shown:
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7. Pressure should not be applied near the puncture site. Squeezing the finger will force
tissue fluid into the blood sample and dilute it.
8. Collect enough blood to fill the capillary tube completely.
9. Place the capillary tube in the eppendorf and mix with the analysis solution.
10. Place the eppendorf in the Biosen analyser for measurement of glucose and lactate.
11. All materials contaminated with blood (tissues, gloves, etc) should be disposed of in
the yellow hazardous waste bag. The lancets should be disposed of in the sealed
container provided.
Glucose = ____________ mmol/L
Lactate = ____________ mmol/L
Question: What are the expected values of glucose and lactate at rest?
To assess the effects of carbohydrate ingestion on blood glucose values, ask one individual
to ingest a sugary drink. Collect repeated blood samples and measure the glucose
concentration at various time intervals. Record the values below and sketch a graph of
blood glucose concentration over time. See Appendix for more details.
Measurement 1 = ____________ mmol/L
Measurement 2 = ____________ mmol/L
Measurement 3 = ____________ mmol/L
Measurement 4 = ____________ mmol/L
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To assess the effects of exercise intensity on blood glucose and lactate values, ask one
individual to exercise for four minutes at a light and moderate intensity (4-5 mins at each)
followed by a 30 second all-out effort. Collect a blood sample at each intensity of exercise.
Question: Before you start, what do you expect to happened to glucose and lactate at each
intensity of exercise and why?
Glucose
Rest = ____________ mmol/L
Light Intensity = ____________ mmol/L
Moderate Intensity = ____________ mmol/L
Maximal Intensity = ____________ mmol/L
Lactate
Rest = ____________ mmol/L
Light Intensity = ____________ mmol/L
Moderate Intensity = ____________ mmol/L
Maximal Intensity = ____________ mmol/L
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Oral Glucose Tolerance
Normal levels for a child over age 2 years to adult: 3.9 - 5.8 mmol/L or 70-105 mg/dl. The processes
within the body work to maintain a blood glucose concentration of about 90 mg of glucose per
deciliter of blood. (One deciliter [dl] is one tenth of a liter (100 ml). Blood glucose of about 90 mg/dl
is referred to as the fasting glucose level because it is the level that is maintained during fasting.
The serum glucose test is helpful in diagnosing metabolic diseases. If an individual is administered a
glucose tolerance test (75 - 100 g glucose), normal findings would include:
Fasting: <6.4mmol/L or 70-115 mg/dl
30 minutes: <11.1 mmol/L or <200 mg/dl
l hour: <11.1 mmol/L or <200 mg/dl
2 hours: <7.8 mmol/L or <140 mg/dl
3 hours: <6.4 mmol/L or 70-115 mg/dl
4 hours: <6.4 mmol/L or 70-115 mg/dl
To change mg/dl to mmol/L of glucose - divide by 18
To change mmol/L to mg/dl of glucose - multiply by 18
True glucose elevations indicate diabetes mellitus, however there are several interfering factors that
affect serum glucose levels:
1. Several forms of stress (e.g., trauma, general anesthesia, cerebrovascular accident, myocardial
infarction) can cause increases.
2. Caffeine can cause increased levels.
3. Several drugs can elevate glucose levels: antidepressants, beta-adrenergic blocking agents,
corticosteroids, diuretics, epinephrine, estrogen, glucagon and several others.
4. Other drugs can decrease blood glucose levels: acetaminophen, alcohol, anabolic steroids,
Clofibrate, Gemfibrozil, insulin, monoamine oxidase inhibitors and several others.
Increased levels - hyperglycemia
If the blood glucose level increases too high (above 11mmol/L). People with diabetes mellitus either
have deficient supplies of insulin produced by the pancreas (insulin dependent diabetes) or their
tissues have become unresponsive to insulin (non-insulin ).
Decreased levels: hypoglycemia
The body will attempt to maintain an optimal blood glucose level. Exercise, like insulin, facilitates the
transport of blood glucose into the muscle. Therefore, insulin levels normally drop during exercise in
order to maintain normal serum glucose.
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