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This Peer Assignment draws on information delivered in the first 5 modules and contributes to20% of your final grade. You have one week to complete and submit the assignment. Yourassignment must be submitted by midnight 25th August 2013. One hour after the assignmentsubmissions close you will have one week to peer grade (using the rubric given you at thattime) and give feedback to three (3) other students assignments. You have one week to gradeyour fellow students work and this task must be done by midnight 8th September 2013.

History:

Tom Smith is a 25 year old triathlete competing in the Hawaii Ironman event that consists of a3.9 km ocean swim, a 180 km bike ride and a 42 km run. The environmental temperature is30C and relative humidity is 75%. At ~3 pm, 8 hr into the event and 500 m from the finishline, Tom staggers and collapses to the ground. The medical support staff arrive to assistTom.

What are the potential problems that may have affected Tom?For each problem make a list of how it may be caused (hypotheses) and potentialmechanisms.

The Medical Team assesses Tom on the roadside. He is confused and incoherent. Whilebeing transported to the medical tent, his coach informs the Team that Tom is a professionaltriathlete who spends ~25 hr per week training. He was well prepared for the event and cameto Hawaii 14 days before the event to acclimatize his body to heat and humidity. Tom was wellat the start of the race at 7 am and two hr prior to the race he had a banana, a bowl of muesliand drank 500 ml of water. He swam well and during the first transition, he started drinking a6% carbohydrate solution containing Na+ and K+ at a rate of ~200 ml every 15 min whichwas his usual fluid intake while racing. He began vomiting after riding ~100 km and began tofall behind the leaders. He continued to vomit several times and was unable to keep his drinkdown. He was sweating freely as he finished the bike leg. His performance deterioratedduring the run, but he was alert and wanted to finish the race, telling his coach that he felt

hot. He continued to vomit. As he approached the last 500 m Tom began to stagger andstruggled to walk in a straight line. His face looked glazed. Despite wanting to finish therace, he collapsed and was placed on a stretcher.

On arrival in the medical tent, Tom was semi-conscious and incoherent. He skin was pink, dryand flaccid with no signs of stings or bites. His body mass was 76 kg (pre-race 81 kg) andvital signs were:

Tom's vital signs Normal Range

Blood Pressure 110/65 mm Hg 100-135/60-86 mm Hg

Heart Rate 150/min 60-100/minRespiratory Rate 20/min 12-16/min

Temperature 40.5 degrees C 36.6 - 37.2 degrees C

Do you want to add to Toms problems? Provide hypotheses for new problems.Would you refine existing hypotheses?

Tom is given two litres of a 10% glucose solution intravenously, then two litres of isotonicsaline. Ice packs are placed near his femoral, carotid and axillary arteries. His temperature is

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measured every 15 min and is heart rate monitored using an ECG. Within 4 hr histemperature returns to the normal range and he gradually regains his conscious state.

Over the next 48 hr, Tom recovered well and managed his disappointment at not finishing theevent for which he had spent so much time preparing. However, he began to have abdominalpain and collapsed. Upon investigation, he was found to have a segment of ischaemic, smallbowel that was the result of a sustained reduction in gut blood flow. The section of gut was

surgically removed and after a period of recuperation, Tom successfully returned to trainingand competition.

The questions in the boxes above are just to guide your thinking and analysis of the case.

Instructions: The work that must be submitted is the answer(s) to each of the FOUR (4)questions in the boxes below. You must type your answer in the box provided. Be aware ofthe word limit for each question.

1. Why was Toms blood glucose low at the end of the race? (Maximum words 150 -4 marks)

2. How does hypoglycemia contribute to fatigue? (Maximum words 150 - 4 marks)3. Why was Toms core temperature so high? (Maximum words 150 - 4 marks)

4. What physiological factors challenge mean arterial pressure for Tom and whatresponses serve to maintain mean arterial pressure within the normal range?(Maximum words 300 - 8 marks)

Week # Week Starting Weekly topic overview Formal assess

1 22nd July 2013

Muscle

muscle contraction and energetics

muscle fibre types, recruitment and

performance

muscle adaptations to exercise

2 29th July 2013

Fuels

overview of exercise metabolism

carbohydrate metabolism

lipid (fat) metabolism

Quiz # 1 (based oof Week 2 (10% of

Opens: Thursday (USA) 2013

Due: Thursday Mid(USA) 2013

NOTE: You have oquiz. You can onlytime. Ensure you hmaterial for the firsattempting this qui

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3 5th August 2013

Oxygen

oxygen uptake kinetics

cardiovascular responses to exercise

respiratory responses to exercise

maximal oxygen uptake determinants andlimits

412th August2013

Heat and Fluids

temperature regulation during exercise

exercise in the heat

fluid balance and replacement duringexercise

Quiz # 2 (based oFluids) end of Wee

Due: Midnight 22n

519th August2013

Fatigue

central and peripheral mechanisms offatigue and their interaction

limits to sports performance sprinting

limits to performance - endurance

Assignment drawin the first 5 modulDue: Midnight 29th

626th August2013

Genes

genes and performance ("are athletes bornor made?"); exercise and gene expression;potential for gene doping?

Final test Quiz #3Oxygen, Heat & FlWeek 6 (60% of fin

Due: Midnight 1st __________________

Peer Grading of Ahour after the Due need to grade at leassignments and gby Midnight 5th Se