SIX WEEKS OF A POLARISED TRAINING INTENSITY DISTRIBUTION LEADS TO GREATER PHYSIOLOGICAL AND PERFORMANCE ADAPTATIONS THAN A THRESHOLD MODEL IN TRAINED CYCLISTS

Craig M. Neal 1 , Angus Murray Hunter 1 ,

Lorraine Brennan 2 , Aifric O’Sullivan 2 , D. Lee Hamilton 1 ,

Giuseppe De Vito 3 , and Stuart D.R. Galloway 1 , *

Author Affiliations

↵ * University of Stirling s.d.r.galloway@stir.ac.uk Submitt
ed 29 May 2012. Revision received 13 December 2012. Accepted 17 December 2012.

Abstract

Aim: To investigate physiological adaptation with two endurance training periods differing in intensity distribution. Methods: In a randomised cross-over fashion, separated by 4-weeks of detraining, 12 male cyclists completed two 6-week training periods: (1) a polarised model (6.4(±1.4)hrs.week -1 ; 80%, 0%, 20% of training time in low, moderate and high intensity zones); and (2) a threshold model (7.5(±2.0)hrs.week -1 ; 57%, 43%, 0% training intensity distribution). Before and after each training period, following 2 days of diet and exercise control, fasted skeletal muscle biopsies were obtained for mitochondrial enzyme activity and monocarboxylate transporter (MCT1/4) expression, and morning first void urine samples collected for NMR spectroscopy based metabolomics analysis. Endurance performance (40km time trial), incremental exercise, peak power output, and high-intensity exercise capacity (95% Wmax to exhaustion) were also assessed. Results: Endurance performance, peak power output, lactate threshold, MCT4, and high-intensity exercise capacity all increased over both training periods. Improvements were greater following polarised than threshold for peak power output (Mean (±SEM) change of 8(±2)% vs. 3(±1)%, P