Methods

Part II will begin 1 week prior to launch (April 2002), and continues for the 10 days of space flight. The testing will commence while Mark is still on Earth. During this time he will have his heart rate energy expenditure relationship recalibrated, to allow for any changes that would have occurred in the two months since his first calibration test. This test will be an exact replica of the first test, as measured with the portable K4B2 Cosmed analyser, and a telemetric heart rate monitor. Mark will have his body composition measured once again. Mark will also have his resting metabolic rate measured using the portable K4B2 Cosmed analyzer, very early in the morning, for a 30 minute period.

12 Hours prior to the launch, Mark will take his first saliva measurement, this measurement will constitute his baseline measurement, after which time he will consume a second stable DLW dose. About 8 hours after the consumption of DLW and on the day of the launch, the second saliva sample will be collected, at least 30 minutes after the consumption of any food or fluid, and before Mark prepares for launch.

In-flight testing: Over the next 10 days, Mark will be required to take various samples and measurements. Firstly on Day’s 3 and 7 Mark will be required to collect a daily saliva sample, in the morning prior to any consumption of food or fluid. Once again, Mark will use the dried dental cotton wool swab to collect the saliva.

To measure Mark’s energy expenditure during the space flight, using heart rate, he will wear a portable halter ECG on day 4 and day 6 in-flight, for a period of 24 hours. The 24 hours will start in the morning, and be continued until the following morning (days 5 and 7), at same time. The portable halter ECG will measure and average heart rate for each minute of the 24 hour period. Energy expenditure will then be estimated using the heart rate energy expenditure calibration test, where energy expenditure values will be applied for each heart rate in the 24 hour period.

For the entire duration of the flight, Mark will be required to keep an accurate physical activity logbook, as well as a log of all his food and fluid consumption and any medications he might use during his space flight.

Post-flight: Following his landing, Mark will have his body composition immediately measured, to assess whether there were any body composition changes during the 10 day space flight. In addition he will also repeat the resting metabolic rate measurement, to determine whether the space flight had any affect on his resting metabolic rate.

All samples will then be collected by the researcher and analysed to calculate his energy expenditure as measured with the DLW method. These results will then be compared to the results obtained from the measurement of energy expenditure with heart rate monitoring, and finally both sets of data will be statistically analysed with the data received from the Pre flight testing, completed 2 months prior to the space flight.