Evaluation of a cycling pre-load time trial protocol in recreationally active humans

The need for greater sensitivity in exercise performance measures is of particular importance in nutritional intervention studies and such measures have been investigated in trained cyclists, but not in those who have no experience of laboratory testing and/or the need to pace their effort. The aim of the present study was to evaluate a mixed design approach (constant load then time-trial) endurance type cycle ergometer protocol using recreationally active participants not well accustomed to cycling. Seven participants including one female (age 25 +/- 5 years; body mass 74.4 +/- 9.3 kg; peak VO(2) 3.91 +/- 0.96 l) completed four repeat cycle tests. The test consisted of a "pre-load" (60 min at 65% of peak VO(2)) followed by a 20 min time trial (performance measure). Reliability for the performance measure was assessed by calculating the individual participant coefficient of variation (CV) and a mean CV for the group. Excluding a familiarisation trial, mean CV for the group was 3.4% (95% confidence interval between 2.0 and 10.1%). It is concluded that the performance test described can be used in recreationally active young adults with lower variation after one familiarisation trial. The protocol might be used to evaluate an intervention if changes in performance are expected to be greater than 3.4%, or greater than around 7% if a signal to noise ratio of 2: 1 was to be considered appropriate.