Microsoft word - pls caffeine_low study.doc

Exercise Metabolism Group
School of Medical Sciences
PO Box 71
Bundoora 3083
Victoria
The effects of caffeine ingestion on self-selected power
output during cycle interval training commenced with
low muscle glycogen content
Plain Language Statement
Dear Potential Participant, You are invited to take part in a research project investigating the effects of caffeine on repeated self-selected maximal intensity cycle training commenced with either low or normal carbohydrate stores. Athletes are often interested in ways to enhance their performance. Although regular training principals, when performed correctly, are known to enhance performance there are a growing number of ways research has identified how athletes/coaches can manipulate exercise-nutrient interactions to enhance the benefits of training. Research outcomes will provide new insight as to whether commencing training sessions with low muscle glycogen stores can enhance the training response and also if caffeine can assist in reducing the fatigue associated with training in a nutrient depleted state. Participation in this project is voluntary, that is, it is your choice to participate. You do not have to take part in this study. If you choose to participate you may withdraw (stop taking part) at any time without having to give a reason. This project has been approved by the RMIT Human Research Ethics Committee and withdrawing from this project will not affect
your relationship with the researchers or RMIT University.
The study involves attendance at the laboratory at RMIT University in Bundoora West
campus (Plenty Rd, Bundoora) for one preliminary visit, and if you agree to, attendance 1-2
days per week for a total of 4 weeks, see Figure 1 below. You will be compensated for travel
and other associated costs.
Experimental Participants
Prior to your first visit to the laboratory you will be required to complete a cardiovascular risk
factor questionnaire form attached at the end of this letter, to enable us to ensure you are not
subjected to undue risk. You will also be required to provide written consent as well as a
detailed training diary listing your current weekly cycling activity before your participation in
the project. After a preliminary maximal test (described below), you will be required to
return to the laboratory a further 6 times over a four week period. All of these occasions will
require you to present to the laboratory in the morning (approximately 8am). All 4 trials
(Figure 2) will consist of two exercise sessions (described below) with all trials being
assigned in to participants of the study in a random order. On two of these occasions you will
be required to remain within the laboratory for a 3 hour period before completing the second
part of the days trial. On the remaining 2 trials you will be allowed to return home after the
morning session and then required to return to the laboratory 24 hours later to complete the
second part of the trial.

Figure 1. Outline of time frame from commencement of preliminary testing to completion
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Figure 2. Outline of the Latin square experimental design. HIGH represents trials where the
HIT session is commenced with normal muscle glycogen concentration. LOW represents trials where the HIT session is commenced with low muscle glycogen concentration. Each trail consists of a glycogen depleting (AT) session followed by 3 hours or 24 hours recovery before commencement of the HIT session. Trials 1 and 3 An overview of the experimental design is shown in figure 3. Each of the four trials will consist of a steady state aerobic cycling bout (AT) at 70% of your peak oxygen consumption (VO2peak) which will be determined during the preliminary testing. The AT bout will then be followed by a high intensity interval cycling bout (HIT; 5x8 min @ self selected-maximal sustainable intensity with 1 min recovery intervals) commenced with either high (HIGH) or low (LOW) carbohydrate stores (figure 2). HIGH trials will be achieved by allowing 24 hours recovery with adequate carbohydrate ingestion to allow adequate carbohydrate restoration. LOW trials will be commenced 3 h after completion of the AT cycling bout with carbohydrate restrained to allow the subsequent HIT session to be commenced with approximately 50% of your muscle glycogen depleted. To determine the effects of caffeine ingestion on self selected power output you will be required to consume either caffeine or a placebo 60 min prior to commencement of the HIT cycling bouts. During the HIGH trials you will be allowed to recover at home for the 24 h period before the HIT cycling bouts; however you will be directed to abstain from any physical activity and to consume the dietary package provided (see below). Due to the shorter time frame (3 hours) between the 100 minute steady state ride and the high intensity interval session you will be required to remain within the laboratory for the LOW trials, with carbohydrate feeding withheld to limit carbohydrate store restoration. The preliminary testing and AT cycling bouts will be performed on an electronically braked cycle ergometer. However HIT bouts will be performed on your own bicycle mounted on a stationary trainer. Average power output will be monitored for each HIT interval using a PowerTap power meter (CyclOps). Throughout the study, after strenuous exercise sessions you will be provided with food and drinks as required, except during 3 hours prior to the HIT session of the LOW trials. After each session we will ensure that you are in a suitable physical state to transport yourself home from the laboratory. Should you or we be concerned with respect to your well being (general health, excessive fatigue) after any such sessions, we will arrange transport and/or assistance as required. Ca
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Figure 3. Trial time line representing exercise, blood and expired air sampling and caffeine
or placebo ingestion.
Please read carefully the detailed descriptions provided regarding the
procedures undertaken, and possible risks associated with completing the
study.

As a participant you will be exposed to a number of risks arising from the maximal exercise
tests and invasive sampling techniques. These are explained in full detail below, along with
the appropriate measures taken to provide you with the safest possible testing environment.
All invasive procedures (blood sampling) will be conducted using sterile equipment.
Maximal exercise test and experimental trials
Blood Sampling
Blood samples will be required from each participant for completion of the project. Five samples
will be taken during each trial, and be ~12 ml volume each (60ml total). In comparison, a
standard Red Cross blood donation is ~400ml. These will be taken from the forearm and/or
ante-cubital fossa (front of elbow joint) using sterile, disposable equipment, by a person
qualified and experienced in blood sampling. The time points for blood sampling are shown in
figure 3.
This will feel exactly the same as any blood sampling that is conducted in a doctor’s visit; pain
may be felt as the needle passes through the skin, but is relatively pain-free thereafter.
Throughout each procedure you will still be mounted on a bicycle, and, this is a common
practice during exercise research. There is a very minor risk of bruising after the sample is taken,
and pressure will be applied for 1-2 minutes to the vein after the needle is removed to minimise
this
Maximal exercise testing You will be asked to partake in a maximal exercise test on an electrically-braked stationary bicycle ergometer. These tests are completed routinely in our laboratory, on subjects of varied fitness abilities. You will be given time to warm up (5-10 minutes) at a pre-selected, leisurely level of effort. Following this you will begin pedalling at 100 Watts after which the work rate will be increased every 2½ minutes by 25 watts until exhaustion (when you can no longer sustain 60 crank revolutions per minute). Throughout the test you will breathe into a specially designed mouth piece that is wired up to an expired air analyser and computer. All breathing apparatus will be thoroughly cleaned in anti-viral and anti-bacterial disinfectants before and after these exercise tests. Trained staff will be present at all times to co-ordinate the tests. The maximal exercise test allows characterisation of your metabolic health and fitness. This test is expected to last approximately 10-15 minutes. At the same time we will also monitor your heart rate using a Polar heart rate monitor. This is done via an electrode belt transmitter worn around your chest and a wrist-mounted receiver. As there is no electrical current involved in the operation of the unit you are in no danger from the monitor, even when sweating heavily. After determining your maximal oxygen uptake (VO2peak), the results will be used to calculate workloads (in Watts) that elicit 70% of your VO2max. You will then cycle at this workload during each of the subsequent AT sessions during each of the four trials. Familiarisation to High Intensity Interval Sessions Approximately 30 minutes after completing the preliminary VO2peak testing you will be required to complete 2 x 5min maximally selected intensity intervals with 1 minute recovery. This will allow you to become familiar with the effort required to complete these repeated bout sessions. Expired air collection Each trial will require intermittent analysis of expired air breathed during the exercise bout. This is the same procedure and equipment described above for the maximal exercise test. Each sample will be taken for approximately 5 minutes and a total of 6 times each trail. Caffeine and placebo In all trials you will be required to orally ingest an opaque capsule 60 min prior to the commencement of the SS-HIT bout of the HIT session (figure 3). The capsule will contain either 3mg/kg of body mass of caffeine or a placebo. This dose of caffeine has been chosen for its well established ergogenic effect (assists performance) and is considered a moderate dose that elicits minimal unwanted side effects. This dose is comparable to 2-3 strong cups of coffee. At the time of ingestion you will not be told if you are receiving the caffeine or placebo pill. This helps the researchers control any unwanted psychological effects that may occur as a result of knowing what trial you are performing. If you desire to know what order you completed the experimental trials, this information will be freely available to you after the entire research study has been completed.
Experimental Controls
Food Intake
You will be provided with a standardised pre-exercise carbohydrate meal the evening prior to
each of the four trials. Furthermore, you will be required to report to the laboratory each time
after an overnight fast, therefore we would like you to have completed your pre-packaged
meal by 9.00pm that evening. After the experimental sessions, the researchers will provide
food and drink for you. A pre-packaged meal will also be supplied for consumption during
the 24 hours recovery of the HIGH trials.

Caffeine and Alcohol
Caffeine and alcohol may affect test results. Accordingly, you will be required to abstain
from caffeine and alcohol for 48 hours prior to all testing and experimental trials.

Physical Activity
For the most reliable and valid test results it is important for you to be physically rested. You
will be asked to perform no physically demanding exercise, aside from that prescribed in this
study, for 36 hours before a laboratory-based session.
Other Important Information

Participation: Your participation is entirely voluntary. You do not have to take part in this
study. If you agree to take part you are free to withdraw at any time without having to give a
reason and your data and all the samples collected will be destroyed.
Confidentiality: Volunteers may be photographed during the completion of this project.
Photographs may be used in the presentation of research findings to demonstrate research
protocols or methods. However, no material that could personally identify you will be used in
any reports or presentation of this project unless informed written consent is provided by the
participant.
Information for each volunteer will be identified by a code so that your name does not appear
on any data sheets. Individual information will be kept for 5 years after the final publication
date in a locked cabinet at RMIT University and only the principal investigators will have
access to this information. At the conclusion of this five-year period all material containing
confidential information will be destroyed. If you wish to gain access to your data contact the
principal researchers and it will be provided to you.
Portions of samples that may remain after completion of analyses will be safely discarded via
incineration, as is common practice for biohazard waste. You will in no way be able to be
identified by any remaining samples after they are discarded.
Results: There may be a delay between data collection, reports and publication. We can
discuss your results with you at the end of your participation in the project, and later on
provide you with details regarding the final results in their entirety.
Funding: This research project is externally funded by The Australian Institute of Sport. Statement of Approval: This study has received ethical approval from the RMIT Human Research Ethics Committee. Please feel free to contact us at any time if you have any questions about this project. You are encouraged to ask questions if you require clarification about any part of this research project or have any queries. Any complaints about your participation in this project may be directed to the Executive Officer, RMIT Human Research Ethics Committee, Research & Innovation, RMIT, GPO Box 2476V, Melbourne, 3001. The telephone number is (03) 9925 2251. Details of the complaints procedure are available from the above address. CARDIOVASCULAR RISK FACTOR QUESTIONNAIRE To be eligible to participate in the experiment you are required to complete the following questionnaire which is designed to assess the risk of you experiencing a harmful cardiovascular event during the course of the trial. A full and honest disclosure of your medical history is vital. Name: Give a brief description of your average weekly activity pattern: Circle the appropriate responses for the following questions: Does your family have a history of premature (<70 years) Cardiovascular problems (eg. heart attack, stroke)? Do you have high blood cholesterol levels? blood-clots in any of your blood vessels Do you have, or have you ever had, any disease or condition that resulted in reduced or slower than Do you have, or have you ever had, any tendency to bleed for long periods after cutting yourself? Have you ever experienced any of the following during exertion (exercise or physical labour) c. Numbness or pins-and-needles in any part of your body Have you suffered any known adverse effects to caffeine ingestion? Do you think you have any medical complaint or any other reason you know of, which you think may prevent you from participating in this trial? I, , believe that the answers to these questions are true and

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