Abstract:
PURPOSE:To develop a protocol for isolating changes in aerodynamic and rolling resistances from field-based measures of power and velocity during level bicycling. METHODS:We assessed the effect of body position (hands on brake hoods vs drops) and tire pressure changes (414 vs 828 kPa) on aerodynamic and rolling resistances by measuring the power (Pext)-versus-speed (V) relationship using commercially available bicycle-mounted power meters. Measurements were obtained using standard road bicycles in calm wind (<1.0 m·s) conditions at constant velocities (acceleration <0.5 m·s) on a flat 200-m section of a smooth asphalt road. For each experimental condition, experienced road cyclists rode in 50-W increments from 100 to 300 W for women (n=2) or 100 to 400 W for men (n=6). Aerodynamic resistance per velocity squared (k) was calculated as the slope of a linear plot of tractive resistance (RT=power/velocity) versus velocity squared. Rolling resistance (Rr) was calculated as the intercept of this relationship. RESULTS:Aerodynamic resistance per velocity squared (k) was significantly greater (P<0.05) while riding on the brake hoods compared with the drops (mean ± SD: 0.175 ± 0.025 vs 0.155 ± 0.03 N·V). Rolling resistance was significantly greater at 60 psi compared with 120 psi (5.575 ± 0.695 vs 4.215 ± 0.815 N). CONCLUSIONS:These results demonstrate that commercially available power meters are sensitive enough to independently detect the changes in aerodynamic and rolling resistances associated with modest changes in body position and substantial changes in tire pressure.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Lim AC,Homestead EP,Edwards AG,Carver TC,Kram R,Byrnes WCdoi
10.1249/MSS.0b013e3181fcb140subject
Has Abstractpub_date
2011-05-01 00:00:00pages
853-60issue
5eissn
0195-9131issn
1530-0315journal_volume
43pub_type
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199807000-00023
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journal_title:Medicine and science in sports and exercise
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journal_title:Medicine and science in sports and exercise
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doi:10.1249/MSS.0b013e3182a78c3a
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journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章,随机对照试验
doi:
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journal_title:Medicine and science in sports and exercise
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journal_title:Medicine and science in sports and exercise
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pub_type: 杂志文章,随机对照试验
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journal_title:Medicine and science in sports and exercise
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journal_title:Medicine and science in sports and exercise
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doi:10.1249/MSS.0000000000002247
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
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pub_type: 临床试验,杂志文章
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journal_title:Medicine and science in sports and exercise
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,随机对照试验
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journal_title:Medicine and science in sports and exercise
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journal_title:Medicine and science in sports and exercise
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199707000-00010
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,随机对照试验
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journal_title:Medicine and science in sports and exercise
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,随机对照试验
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journal_title:Medicine and science in sports and exercise
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