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Exercise in Extreme Conditions

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Title: Exercise in Extreme Conditions


1
Exercise in Extreme Conditions
  • PED 4900

2
Air Pollution
3
Carbon Monoxide
  • A primary, orderless pollutant formed from
    automobiles, factories, etc.
  • 210-230 times greater affinity to RBC than oxygen
  • Less oxygen bound to hemoglobin and myoglobin
  • Increase anaerobic metabolism (lower lactate
    threshold, decrease endurance and VO2max).

4
Smoking
  • Decrease performance if smoke 10 or fewer
    cigarettes or ride1 hr in a car with a smoker
  • Increase pulmonary airway resistance and oxygen
    cost of breathing

5
Ozone
  • A secondary pollutant formed when ultraviolet
    rays hit oxygen
  • Most common photochemical oxidant
  • When concentrated, eye irritation, chest
    tightness, breathlessness, coughing, and nausea.
  • Reduces oxygen transfer at the lung

6
Sulfur dioxide
  • Formed from burning coal and oil
  • Upper airway irritant that can cause significant
    discomfort

7
Exercise and Pollution
  • Air pollution is greatest during commute hours
    and warmest time of day
  • Cause bronchioconstriction which is exaggerated
    during exercise
  • Mouth breath worse than nose breathing less
    filtering
  • Studies show decrement in performance with
    significant air pollution

8
Biological Rhythms and Travel
The Beta-Q Biorhythms program charts the three
cycles in separate frames underneath each other
for ease of viewing and uses daily indicator bars
to visually indicate the state of the rhythms on
the view date, with colors representing the
phases, critical and mini-critical days.
9
Biological Rhythms and Travel
  • Physiological functions follow certain rhythms
    Circadian, Cicaspetian, Circalunar, and
    Circa-annual.
  • Examples of functions with regular rhythm
  • Sleep, body temperature, heart rate, blood
    pressure, metabolic rate hormone secretion
  • Strength, power, reaction time, and RPE.
  • Most studies show performance is maximized in the
    afternoon

10
Jet lag
  • Characterized by fatigue, malaise, sluggishness,
    decrease reaction time, and disorientation
  • Cause may be due to loss of sleep, irregular and
    unfamiliar meals, dehydration, and disturbance of
    biological clock
  • Flying can increase dehydration due to low
    humidity (20) inside the cabin
  • Eastbound travel seems to cause more problems.

11
Micogravity, Immobilization, and Bed Rest
12
Micogravity, Immobilization, and Bed Rest
  • Less gravitational pull as an object moves
    further away from the earth
  • At 8,000 miles body weight is only 25 of its
    value on earth
  • At 210,000 miles bodyweight is 0 of its value on
    earth
  • No or microgravity unloads the posture muscles
    and any stress to the bones

13
Muscle
  • Atrophy from a decrease in protein synthesis but
    some strength is maintained
  • 17 day space flight produced no change in muscle
    strength but a 8-11 decrease in size
  • 28 day space flight produced 10-20 decrease in
    strength and 10 decrease in size
  • Resistance training in space can attenuate the
    loss of muscle size and function

14
Bone
  • Bone losses range from 0-6
  • Greater loss from weight baring bones (e.g.
    calcaneus)
  • Could be due to a combination of reduced bone
    formation and increased bone resorption

15
Cardiovascular
  • Reduction in plasma volume
  • Reduced hydrostatic pressure and thus venous
    pooling
  • Increase venous return and cardiac output
  • Increase blood flow through kidneys
  • Result in orthostatic hypotension upon return to
    earth

16
Exercise on the International Space Station
  • The cycle ergometer looks much like an exercise
    bicycle. It gives aerobic conditioning to legs
    and arms while also conditioning the heart. With
    monitors to record vital signs and straps to keep
    them in place, pedaling the ergometer provides
    toning and conditioning the astronauts' need.
  • The treadmill used in space is a bit different
    than one used on Earth. Because astronauts are
    nearly weightless, they need to be harnessed to
    the machine and weighted down as they walk.
    Otherwise, even if they managed to stay in place
    on the treadmill, their exercising would be
    nearly effortless and ineffective.
  • The Interim Resistance Exercise Device (IRED)
    uses cylinders filled with disks to create a
    push-pull resistance. Astronauts can exercise the
    muscles that don't get much action in
    microgravity.

17
Ultra-Endurance
18
Ultraviolet exposure in the Ironman triathlon
MATTHIAS MOEHRLEDepartment of Dermatology,
University of Tuebingen, GERMANYMEDICINE AND
SCIENCE IN SPORTS AND EXERCISE 2001331385-1386
  • Purpose Skin cancer is increasing worldwide and
    exposure to ultraviolet (UV) radiation is thought
    to be the most important environmental risk
    factor. People practicing outdoor sports are
    exposed to considerable amounts of UV radiation
    from the sun.
  • Methods Three triathletes participated in the
    Ironman Triathlon World Championships 1999 in
    Hawaii (3.9-km swim, 180.2-km bike, 42.4-km run).
    They attached Bacillus subtilis spore film
    dosimeters (VioSpor) on the back between their
    shoulders. The dosimeter system measured
    cumulative biologically weighted erythemal UV
    exposure. UV exposure is given in minimal
    erythema doses (1 MED corresponds to 250 Jm-2 at
    298 nm).
  • Results The mean personal UV exposure was 8.3
    MED (6.9-9.7 MED) after 843 to 944 h of
    competition corresponding to 0.8 to 1.3 MEDh-1
    (bike and run). The athletes were sunburned
    despite the use of water-resistant sunscreen (SPF
    25) on sun exposed skin.
  • Conclusion The International Radiation
    Protection Agency has issued guidelines for
    professional UV exposure. Ironman triathletes
    considerably exceeded these limits of exposure
    similar to other outdoor sports. Professional and
    amateur athletes should be aware of hazards
    caused by UV radiation. Adequate protection by
    water-resistant sunscreens and clothing as well
    as training and competition schedules with low
    sun exposure seem to be a reasonable
    recommendation.

19
ULTRA-ENDURANCE CYCLING A FIELD STUDY OF HUMAN
PERFORMANCE DURING A 12-HOUR MOUTAIN BIKE RACE.
JON LINDERMAN, TIM DEMCHAK, JULIE DALLAS, JANET
BUCKWORTH. JEPONLINE. 20036(3)10-19.
  • TO INVESTIGATE CHANGES IN PHYSIOLOGICAL AND
    PSYCHOLOGICAL FUNCTION DURING ULTRA-ENDURANCE
    EVENTS, 6 HEALTHY CYCLISTS (31.51.6 YEARS) WERE
    STUDIED DURING A 12-HOUR MOUNTAIN BIKE RACE.
  • SUBJECTS COVERED 119-170 KM, AT AVERAGE
    VELOCITIES OF 11-14 KM/HOUR.
  • DURING THE FIRST TWO HOURS OF THE EVENT HEART
    RATES AVERAGED 155-157 BEATS/MIN, DECLINED
    SIGNIFICANTLY DURING THE THIRD HOUR (14214
    BEATS/MIN Plt0.05), AND WAS LARGELY UNCHANGED
    THROUGHOUT THE REMAINING NINE HOURS OF THE RACE.
  • SUBJECTS CONSUMED 1550-3300 KCALS DURING THE
    EVENT WITH AN AVERAGE OF 66276 G OF
    CARBOHYDRATE. ALTHOUGH SUBJECTS CONSUMED
    4500-6400 ML OF FLUID DURING THE RACE, HYDRATION
    STATUS, ASSESSED FROM CHANGES IN BODY WEIGHT,
    INDICATED A DEHYDRATION INDIRECTLY QUANTIFIED AS
    A 4 DECREASE IN BODY WEIGHT PRE- TO POST RACE
    (2.31.4 KG Plt0.05).
  • USING THE 10-POINT BORG SCALE SUBJECTS RATING OF
    PERCEIVED EXERTION (RPE) INCREASED HOURLY FROM
    4.01.3 AFTER THE FIRST HOUR OF COMPETITION TO
    9.21.0 DURING THE TWELFTH HOUR OF COMPETITION
    (Plt0.05).
  • PROFILE OF MOODS STATE (POMS) ADMINISTERED DURING
    THE EVENT REVEALED DECLINES IN VIGOR PRE- TO
    POST-RACE (11.52.3 VS. 3.81.7 Plt0.05), WITH
    CONCOMITANT INCREASES IN FATIGUE SCORES (5.32.8
    VS. 19.30.5 Plt0.05).
  • RESULTS OF THE PRESENT INVESTIGATION SUGGEST
    GREATER DECLINES IN MENTAL THAN PHYSIOLOGICAL
    FUNCTION DURING PROLONGED OFF-ROAD CYCLING
    COMPETITION.

20
Energy expenditure during 2 wk of an
ultra-endurance run around Australia REBECCA J.
HILL PETER S. W. DAVIESSchool of Human Movement
Studies, Faculty of Health, Queensland University
of Technology, Brisbane, Queensland, AUSTRALIA
and Childrens Nutrition Research Centre,
Department of Paediatrics and Child Health, Royal
Childrens Hospital, Binsbane, Queensland,
Australia.MEDICINE AND SCIENCE IN SPORTS AND
EXERCISE 200133148-151
  • Purpose For ultra-endurance athletes, whose
    energy expenditure is likely to be at the
    extremes of human tolerance for sustained periods
    of time, there is increased concern regarding
    meeting energy needs. Due to the lack of data
    outlining the energy requirements of such
    athletes, it is possible that those participating
    in ultra-endurance exercise are compromising
    performance, as well as health, as a result of
    inadequate nutrition and energy intake. To
    provide insight into this dilemma, we have
    presented a case study of a 37-yr-old
    ultra-marathon runner as he runs around the coast
    of Australia.
  • Methods Total energy expenditure was measured
    over a 2-wk period using the doubly labeled water
    technique.
  • Results The average total energy expenditure of
    the case subject was 6321 kcald-1. Based on the
    expected accuracy and precision of the doubly
    labeled water technique the subjects total
    energy expenditure might range between 6095 and
    6550 kcald-1. The subjects average daily water
    turnover was 6.083 L over the 14-d period and
    might range between 5.9 L and 6.3 Ld-1.
  • Conclusions This information will provide a
    guide to the energy requirements of
    ultra-endurance running and enable athletes,
    nutritionists, and coaches to optimize
    performance without compromising the health of
    the participant.

21
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