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Preservation of cognitive performance with age during exertional heat stress under low and high air velocity.

Wright Beatty HE, Keillor JM, Hardcastle SG, Boulay P, Kenny GP - Biomed Res Int (2015)

Bottom Line: Older adults may be at greater risk for occupational injuries given their reduced capacity to dissipate heat, leading to greater thermal strain and potentially cognitive decrements.PASAT numbers of correct responses at end exercise were similar for young (low = 49 ± 3; high = 51 ± 3) and older (low = 46 ± 5; high = 47 ± 4) males and across air velocity conditions, and when scored relative to age norms.Psychological sweating, or an increased sweat rate with the administration of the PASAT, was observed in both age groups in the high condition.

View Article: PubMed Central - PubMed

Affiliation: Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, 125 University Private, Montpetit Hall, Room 367, Ottawa, ON, Canada K1N 6N5 ; Flight Research Lab, National Research Council Canada, Ottawa, ON, Canada K1A 0R6.

ABSTRACT

Unlabelled: Older adults may be at greater risk for occupational injuries given their reduced capacity to dissipate heat, leading to greater thermal strain and potentially cognitive decrements.

Purpose: To examine the effects of age and increased air velocity, during exercise in humid heat, on information processing and attention.

Methods: Nine young (24 ± 1 years) and 9 older (59 ± 1 years) males cycled 4 × 15 min (separated by 15 min rest) at a fixed rate of heat production (400 W) in humid heat (35°C, 60% relative humidity) under 0.5 (low) and 3.0 (high) m·s(-1) air velocity wearing coveralls. At rest, immediately following exercise (end exercise), and after the final recovery, participants performed an abbreviated paced auditory serial addition task (PASAT, 2 sec pace).

Results: PASAT numbers of correct responses at end exercise were similar for young (low = 49 ± 3; high = 51 ± 3) and older (low = 46 ± 5; high = 47 ± 4) males and across air velocity conditions, and when scored relative to age norms. Psychological sweating, or an increased sweat rate with the administration of the PASAT, was observed in both age groups in the high condition.

Conclusion: No significant decrements in attention and speeded information processing were observed, with age or altered air velocity, following intermittent exercise in humid heat.

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Related in: MedlinePlus

Rectal temperature ((a) and (c)) and heart rate ((b) and (d)) at the start of the paced auditory serial addition task (PASAT) and averaged over the 3-minute duration of the PASAT when administered at baseline (white), end of the 4th exercise bout (end exercise; grey), and end of the final recovery (end recovery; black) in young and older males under low and high air velocity. Values are mean ± SE. ∗ Main effect of time; end exercise and end recovery versus baseline for rectal temperature; end exercise and end recovery versus all time points for heart rate; # main effect of air velocity condition; † main effect of age; ‡ significant difference between pre-PASAT and PASAT within each air velocity condition and age group.
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fig1: Rectal temperature ((a) and (c)) and heart rate ((b) and (d)) at the start of the paced auditory serial addition task (PASAT) and averaged over the 3-minute duration of the PASAT when administered at baseline (white), end of the 4th exercise bout (end exercise; grey), and end of the final recovery (end recovery; black) in young and older males under low and high air velocity. Values are mean ± SE. ∗ Main effect of time; end exercise and end recovery versus baseline for rectal temperature; end exercise and end recovery versus all time points for heart rate; # main effect of air velocity condition; † main effect of age; ‡ significant difference between pre-PASAT and PASAT within each air velocity condition and age group.

Mentions: During the low and high air velocity conditions, no overall differences were observed between the young and older males for Tre (Figures 1(a) and 1(c)), LSRFA (Figures 2(a) and 2(c)), LSRUB (Figures 2(b) and 2(d)), PASAT Z score (Figures 3(b) and 3(e)), or PASAT percentile (Figures 3(c) and 3(f)). A group x time interaction was observed for heart rate, such that heart rate was greater in the young males compared to older males at end exercise with a trend at end recovery (P = 0.084) (Figures 1(b) and 1(d), trend for age main effect P = 0.067). There were no differences between the young and older males for percent of maximum heart rate in either the low condition at baseline (young = 41.6  ±  2.5, older = 44.1  ±  2.3%), end exercise (young = 80.0 ± 3.2, older = 77.3 ± 1.2%), or end recovery (young = 62.7 ± 3.3, older = 64.9 ± 2.0%), or the high condition at baseline (young = 39.0  ±  2.1, older = 41.1  ±  1.1%), end exercise (young = 67.9 ± 2.9, older = 71.1 ± 2.0%), or end recovery (young = 46.4 ± 2.9, older = 53.3 ± 2.3%). A group x time interaction was observed for PASAT number of correct responses, such that the number of correct responses were greater at end recovery compared to baseline and end exercise for the older males (Figures 3(a) and 3(d)).


Preservation of cognitive performance with age during exertional heat stress under low and high air velocity.

Wright Beatty HE, Keillor JM, Hardcastle SG, Boulay P, Kenny GP - Biomed Res Int (2015)

Rectal temperature ((a) and (c)) and heart rate ((b) and (d)) at the start of the paced auditory serial addition task (PASAT) and averaged over the 3-minute duration of the PASAT when administered at baseline (white), end of the 4th exercise bout (end exercise; grey), and end of the final recovery (end recovery; black) in young and older males under low and high air velocity. Values are mean ± SE. ∗ Main effect of time; end exercise and end recovery versus baseline for rectal temperature; end exercise and end recovery versus all time points for heart rate; # main effect of air velocity condition; † main effect of age; ‡ significant difference between pre-PASAT and PASAT within each air velocity condition and age group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385631&req=5

fig1: Rectal temperature ((a) and (c)) and heart rate ((b) and (d)) at the start of the paced auditory serial addition task (PASAT) and averaged over the 3-minute duration of the PASAT when administered at baseline (white), end of the 4th exercise bout (end exercise; grey), and end of the final recovery (end recovery; black) in young and older males under low and high air velocity. Values are mean ± SE. ∗ Main effect of time; end exercise and end recovery versus baseline for rectal temperature; end exercise and end recovery versus all time points for heart rate; # main effect of air velocity condition; † main effect of age; ‡ significant difference between pre-PASAT and PASAT within each air velocity condition and age group.
Mentions: During the low and high air velocity conditions, no overall differences were observed between the young and older males for Tre (Figures 1(a) and 1(c)), LSRFA (Figures 2(a) and 2(c)), LSRUB (Figures 2(b) and 2(d)), PASAT Z score (Figures 3(b) and 3(e)), or PASAT percentile (Figures 3(c) and 3(f)). A group x time interaction was observed for heart rate, such that heart rate was greater in the young males compared to older males at end exercise with a trend at end recovery (P = 0.084) (Figures 1(b) and 1(d), trend for age main effect P = 0.067). There were no differences between the young and older males for percent of maximum heart rate in either the low condition at baseline (young = 41.6  ±  2.5, older = 44.1  ±  2.3%), end exercise (young = 80.0 ± 3.2, older = 77.3 ± 1.2%), or end recovery (young = 62.7 ± 3.3, older = 64.9 ± 2.0%), or the high condition at baseline (young = 39.0  ±  2.1, older = 41.1  ±  1.1%), end exercise (young = 67.9 ± 2.9, older = 71.1 ± 2.0%), or end recovery (young = 46.4 ± 2.9, older = 53.3 ± 2.3%). A group x time interaction was observed for PASAT number of correct responses, such that the number of correct responses were greater at end recovery compared to baseline and end exercise for the older males (Figures 3(a) and 3(d)).

Bottom Line: Older adults may be at greater risk for occupational injuries given their reduced capacity to dissipate heat, leading to greater thermal strain and potentially cognitive decrements.PASAT numbers of correct responses at end exercise were similar for young (low = 49 ± 3; high = 51 ± 3) and older (low = 46 ± 5; high = 47 ± 4) males and across air velocity conditions, and when scored relative to age norms.Psychological sweating, or an increased sweat rate with the administration of the PASAT, was observed in both age groups in the high condition.

View Article: PubMed Central - PubMed

Affiliation: Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, 125 University Private, Montpetit Hall, Room 367, Ottawa, ON, Canada K1N 6N5 ; Flight Research Lab, National Research Council Canada, Ottawa, ON, Canada K1A 0R6.

ABSTRACT

Unlabelled: Older adults may be at greater risk for occupational injuries given their reduced capacity to dissipate heat, leading to greater thermal strain and potentially cognitive decrements.

Purpose: To examine the effects of age and increased air velocity, during exercise in humid heat, on information processing and attention.

Methods: Nine young (24 ± 1 years) and 9 older (59 ± 1 years) males cycled 4 × 15 min (separated by 15 min rest) at a fixed rate of heat production (400 W) in humid heat (35°C, 60% relative humidity) under 0.5 (low) and 3.0 (high) m·s(-1) air velocity wearing coveralls. At rest, immediately following exercise (end exercise), and after the final recovery, participants performed an abbreviated paced auditory serial addition task (PASAT, 2 sec pace).

Results: PASAT numbers of correct responses at end exercise were similar for young (low = 49 ± 3; high = 51 ± 3) and older (low = 46 ± 5; high = 47 ± 4) males and across air velocity conditions, and when scored relative to age norms. Psychological sweating, or an increased sweat rate with the administration of the PASAT, was observed in both age groups in the high condition.

Conclusion: No significant decrements in attention and speeded information processing were observed, with age or altered air velocity, following intermittent exercise in humid heat.

Show MeSH
Related in: MedlinePlus