Body adaptations during exercise in extreme cold environment

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SimoneMarello

Thermoregulation

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• Habituation

• Metabolic cold adaptations

• Insulative cold adaptations

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FIRST RESPONSES

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Toner and McArdle 1988

Maximal shivering:

1. Increasing of metabolism up to 4.2

2. 40% of VO2 max

Vasoconstriction

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Hypothermia

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• Mild

• Moderate

• Severe

Hypothermia

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Acclimatisation to cold as save energy

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“Physiological changes occurring in an organism exposed for days or weeks to an extreme environment, which lead to extended tolerance of cold (survival), improved comfort, and decreased energy expenditure”

Folks 1974

Andersen et al (1960)

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Muller, M. D. et al 2012

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Castellani et al 2001

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Low-intensity exercise

• Walking at 5 km h (30% Vo2 max)

• 5-6 hours at 5 C

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Moderate intensity exercise

• 1979 ski marathon • Temperature range from -28˚C to -18˚C• ~75% Vo2 max • 5-10 h• Only 6% were able to complete the race

Faulkner, J. A., White, T. P., & Markley, J. M. (1981). The 1979 Canadian ski marathon: a natural experiment in hypothermia. In Exercise in health and disease. Balke

symposium, Springfield (Vol. 101, pp. 184-185).

Moderate intensity exercise

At temperatures as low as -10 has been shown not substantial difference from the responses at 20 C when exercising at 64% Vo2 max. (Layden et al 2002)

Mariann S. et al 2009

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Maximal intensity exercise

Short intensive exercises:

• Jumping decrease 4.2% per 1 C

• Sprinting decrease 5.1% per 1 C

Bergh, U., & Ekblom, B. (1979). Influence of muscle temperature on maximal muscle strength and power output in human skeletal muscles. Acta physiologica

scandinavica, 107(1), 33-37.

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Oska et al 1997

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To summarise

• During aerobic exercise, shivering increases metabolic and oxygen consumption

• Maximal intensity exercises

• Decrease of muscular temperatures may lead to poorer performances

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Keep in mind..

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• The intensity of the exercises

• Environmental temperatures

• Duration of exposure

For the future..

• Additional studies in extreme cold

• Long exposure effects

Thank you everyone for your attention

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