title: Interindividual Variation in the Relationship of Different Intensity Markers-A Challenge for Targeted Training Prescriptions.
abstract: OBJECTIVE
  Training intensities are frequently prescribed as relative workloads based on a single reference value (e.g. maximum oxygen uptake). However, exercise-induced physical strain is multifaceted and large interindividual variability in intensity markers has been reported for constant load exercise with standardized relative intensity. This questions the accuracy of (univariate) relative intensities in targeting specific training stimuli. The present trial aims to investigate interindividual variability in the relationship of strain indicators using interpolated performance curves derived from constant load tests at different workloads. This approach enables the prediction of other indicators based on a chosen reference and subsequent comparison of predictive accuracy between group-based and individualized regression models.
  
  
  METHODS
  15 competitive cyclists completed a stepwise incremental cycling test followed by 5 constant load tests with the same absolute workloads as in the stepwise incremental test. The highest of theses workloads which yielded a lactate (BLa) steady state was repeated enabling estimation of intraindividual variability. From constant load tests, the courses of BLa relative to the respective reference value (e.g. %VO2peak) were interpolated by polynomial regression. Variability between individual regression curves was analyzed by mixed modeling. Predictive accuracy was estimated as the sum of squared differences between predicted and observed values.
  
  
  RESULTS
  The proportion of total variation in the course of BLa relative to the respective reference parameter accounted for by subject identity ranged between 36 and 51%. A significant increase in predictive accuracy was observed for VO2peak and HRmax, respectively, as predicting parameters.
  
  
  CONCLUSIONS
  These results are in support of a multivariable, individualized approach to intensity prescriptions when aiming at accurately targeted perturbations of homeostasis.
authors: Saarland University, Institute of Sports and Preventive Medicine, Saarbrücken, Germany.
authors: Florian
authors: http://orcid.org/0000-0001-5750-2202
authors: F
authors: Egger
authors: Saarland University, Institute of Sports and Preventive Medicine, Saarbrücken, Germany.
authors: Tim
authors: T
authors: Meyer
authors: Saarland University, Institute of Sports and Preventive Medicine, Saarbrücken, Germany.
authors: Anne
authors: A
authors: Hecksteden
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology* / Q000706:statistics & numerical data*; D015415:Biomarkers; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007206:Individuality; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D064797:Physical Conditioning, Human / Q000379:methods*; D012016:Reference Values
chemical_list: D015415:Biomarkers