Table 1. Interindividual variation and predictive accuracy.

Independent variable	Interindividual variation		Predictive accuracy
	% total variance	total*	change with individualized prediction #
%VO2peak	36	1,00	31	0.01
%VO2R	51	1,44	29	0.42
%HRmax	40	0,74	75	0.04
%HRR	44	0,84	81	0.09

Dependent variable in all cases: blood lactate concentration

SD: Standard deviation, %: percentage of, HR_max: maximum heart rate, HR_R: heart rate reserve, VO_2peak: peak oxygen uptake, VO_2R: oxygen uptake reserve.

* As SD [mmol·l^-1]

^# The sum of squared differences between predicted and observed values for the repeated constant load test is used as estimate of predictive accuracy. The increase in predictive accuracy with individualized prediction is quantified as % decrease in sum of squared differences. The significance level for the alpha error was set at p<0.05.