My mate forwarded me a link to uni study, which I've now signed up for. It seems ideal for audaxers etc to find out their limits and partake in some research.
I spoke to the researchers and they said they still need people (the main criteria being, you must be able to cycle for over 6 hrs), so I thought I'd post it here (hope it's ok).
If you're interested contact the researchers below. They're running tests at Brunel Uni, starting next week, so pretty handy for those London based who can spare a little time.
Information to Research Participants
Title of study:
Effect of dehydration on cardiac function following prolonged exercise
Contact:
Lee Eldridge or Gareth Nicholas
Email: ljeldridge@gmail.com Phone: 07843230745 ss07ggn@brunel.ac.uk 07977102590
Place of the experiment: Physiology Laboratory, Centre for Sports Medicine & Human Performance, Heinz Wolff Building, Brunel University, Middlesex UB8 3PH.
Study background
Research has reported alterations in cardiac function and the occurrence of cardiac stress following prolonged exercise, such as a marathon. The causes of the cardiac changes and stress are undefined. It is possible that there is an association with dehydration. It is recognised that dehydration effects exercise performance; therefore perhaps an increase in dehydration also has an impact upon the heart.
During prolonged exercise there is an increased risk of dehydration due to increases in sweating, necessary to facilitate heat loss as a result of metabolic heat production and thus core body temperature. However, little is known about the independent contribution of dehydration to exercise-induced cardiac fatigue and damage.
Specific aims of the study:
The main aim of this study is to determine the effect of exercise-induced dehydration on cardiac function and stress after prolonged cycling exercise.
Participation: your participation in the study is voluntary and you can withdraw at any time without penalty, nor giving any reasons.
Participants: Participants in this experiment will be 10 healthy, active males between the ages of 18-40 years.
Exclusion criteria
- Previous history of lower limb muscle, tendon, ligament or knee joint injury
- Known cardiac diseases and/or cardiovascular risk factors
- Aversion to blood and needles or known allergy to local anaesthetic drug
- Under treatment for any disease
How long will the study last?
This study requires 5 visits to the laboratory, with initial testing (1 hour) and the main experiments (6 hours each). Subsequent to the 6 hour cycle a 24 hours post exercise laboratory visit will be required (30 minutes). All visits will take place within a 6 week period.
Participant requirements
1. During the first visit, you will perform a short progressive cycling test to exhaustion (VO2max).
2. During your second and third visit, you will cycle for 6 hours at a sub-maximal intensity calculated from your first visit.
3. 24 hours post exercise visit, approximately 30 minutes cardiac assessment to monitor reversibility.
What data collection involves:
During visit 1:
1. Heart rate measurement via ECG.
2. Oxygen uptake measured at the mouth via analyses of the air you breathe.
During visits 2 and 3:
Procedures 1 and 2 above and
3. Rectal temperature measurement using a rectal probe to be self-inserted into the rectum 15 cm past the anal sphincter.
4. Venous blood sampling through a thin flexible plastic catheter inserted with
a needle into your anti-cubital vein.
5. Echocardiographic assessment of cardiac function.
Catheterisations will be performed under local anaesthesia by a certified phlebotomist. A total amount of 70 ml of blood will be withdrawn over the course of one experimental session. This is less than the amount of blood withdrawn during a normal blood donation (450 ml). Blood volume will be maintained by reinfusion of saline after each sample.
During your second visit all of the dehydration and sweat losses will be off-set by the consumption of a carbohydrate-electrolyte sports drink to maintain your pre-exercise hydration levels. During the third visit, only some of your dehydration and sweat losses will be corrected by the consumption of a smaller amount of the same carbohydrate-electrolyte sports drink. During both visits you will be allowed to eat the same amount of food that you prefer.
What are the risks associated with the experiment? Except for the venous catheterization, none of the above techniques are painful, with no associated risks or contraindications. The risks related to venous catheterization include:
- Haematoma Pressure will be applied by the phlebotomist after removal of the catheters to constrain the blood flow within the vessel and therefore minimise the chances of developing a haematoma.
- Bleeding occurs in less than 1% of the cases and can be prevented by pressure application.
- Infection. The risk of infection is present, as in all procedures which require puncture or cutting of the skin, however, this risk is very minimal when strict sterile procedures are followed.
Although invasive, there are no known risks in the measurement of rectal temperatures using a rectal probe and it is a common procedure in clinical and exercise settings.
There are no risks associated with echocardiography and a hypoallergenic ultrasound gel will be used to avoid skin irritation.
Several members of the research team have extensive experience with the procedures used in this experiment as demonstrated by numerous publications in Sports Medicine and Physiology scientific journals.
Requirements or abstentions imposed upon the participants prior and after the main experiment.
You will be asked to refrain from:
1. heavy exercise 24 hours prior to the experiment
2. alcohol ingestion 12 hours prior to the experiment
3. caffeine intake at least 12 hours before the experiment
4. eating 1 hour before the experiment
Data collected: An identification code will be ascribed to each participant and all data collected will be electronically compiled anonymously. Your personal information will remain confidential, and we will not disclose any of your personal information without your permission. The data will be stored at the School of Sport and Education, Brunel University, West London, for a maximum of 5 years. Results will be presented anonymously in scientific conferences and research articles.
Benefit of participating in the study: You will gain information about your aerobic fitness via the VO2max test and will also gain information on your physiological and cardiac responses during and after prolonged exercise. Overall, this information could inform and benefit your training programmes and competition strategies.
