Abstract:
INTRODUCTION:A nonlinear dynamic systems model has previously been proposed to explain pacing strategies employed during exercise. PURPOSE:This study was conducted to examine the pacing strategies used under varying conditions during the cycle phase of an Ironman triathlon. METHODS:The bicycles of six well-trained male triathletes were equipped with SRM power meters set to record power output, cadence, speed, and heart rate. The flat, three-lap, out-and-back cycle course, coupled with relatively consistent wind conditions (17-30 km x h(-1)), enabled comparisons to be made between three consecutive 60-km laps and relative wind direction (headwind vs tailwind). RESULTS:Participants finished the cycle phase (180 km) with consistently fast performance times (5 h, 11 +/- 2 min; top 10% of all finishers). Average power output (239 +/- 25 to 203 +/- 20 W), cadence (89 +/- 6 to 82 +/- 8 rpm), and speed (36.5 +/- 0.8 to 33.1 +/- 0.8 km x h(-1)) all significantly decreased with increasing number of laps (P < 0.05). These variables, however, were not significantly different between headwind and tailwind sections. The deviation (SD) in power output and cadence did not change with increasing number of laps; however, the deviations in torque (6.8 +/- 1.6 and 5.8 +/- 1.3 N x m) and speed (2.1 +/- 0.5 and 1.6 +/- 0.3 km x h(-1)) were significantly greater under headwind compared with tailwind conditions, respectively. The median power frequency tended to be lower in headwind (0.0480 +/- 0.0083) compared with tailwind (0.0531 +/- 0.0101) sections. CONCLUSION:These data show evidence that a nonlinear dynamic pacing strategy is used by well-trained triathletes throughout various segments and conditions of the Ironman cycle phase. Moreover, an increased variation in torque and speed was found in the headwind versus the tailwind condition.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Abbiss CR,Quod MJ,Martin DT,Netto KJ,Nosaka K,Lee H,Surriano R,Bishop D,Laursen PBdoi
10.1249/01.mss.0000210202.33070.55subject
Has Abstractpub_date
2006-04-01 00:00:00pages
726-34issue
4eissn
0195-9131issn
1530-0315pii
00005768-200604000-00018journal_volume
38pub_type
杂志文章abstract::A previous study has shown that subjects who entrain breathing during cycling exhibit a lower oxygen consumption (VO2) compared with random breathing. We sought to investigate the hypothesis that entrainment of breathing during rowing improved biomechanical economy (reduced VO2) compared with spontaneous breathing. A ...
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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abstract::The effects of supervised physical training (PT) and lifestyle education (LSE) on risk factors for coronary artery disease and non-insulin-dependent diabetes mellitus were compared in obese 7- to 11-yr-old black girls. The subjects were divided into two groups. The PT group (N = 12) completed a 5-d.wk-1, 10-wk, aerobi...
journal_title:Medicine and science in sports and exercise
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
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journal_title:Medicine and science in sports and exercise
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pub_type: 临床试验,杂志文章
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pub_type: 杂志文章,评审
doi:10.1249/MSS.0b013e3181de7a8a
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journal_title:Medicine and science in sports and exercise
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doi:10.1097/00005768-200111000-00004
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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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doi:10.1249/MSS.0000000000000469
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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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doi:
更新日期:1991-03-01 00:00:00
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journal_title:Medicine and science in sports and exercise
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doi:10.1249/MSS.0000000000002004
更新日期:2019-09-01 00:00:00
abstract::The effects of weight loss (dehydration) techniques (which mimicked techniques used prior to actual competition) used by intercollegiate wrestlers on selected physiological parameters (strength, anaerobic power, anaerobic capacity, the lactate threshold (LT), and peak aerobic power) were examined in seven intercollegi...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1990-04-01 00:00:00
abstract:INTRODUCTION:Parents play a critical role in shaping children's attitudes, beliefs, and behaviors, including those around physical activity and inactivity. Our ability to identify which practices effectively promote children's physical activity and limit inactivity is limited by existing measurement instruments. This p...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e31829d27de
更新日期:2013-12-01 00:00:00
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199701000-00013
更新日期:1997-01-01 00:00:00
abstract:PURPOSE:To compare four different methods of measuring physical activity (PA) in adult women under free-living conditions. METHODS:Twelve women participated in a 7-d period during which PA was assessed via self-report, accelerometry and step-counting. Subjects wore at the waist a Tritrac-R3D accelerometer, a Computer ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200007000-00021
更新日期:2000-07-01 00:00:00
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journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3182a77220
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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
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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
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更新日期:2016-05-01 00:00:00