This study examines how the individual anaerobic threshold (IAT) for middle distance runners develops during
the basic training periods in autumn (TP-1; 12 weeks) and spring (TP-2; 8 weeks), and during the competition periods in
winter (CP-1; 8 weeks) and summer (CP-2; 16 weeks), depending on subjects' training intensity and volume.
Eight middle distance runners (T) and eight controls (UT) underwent five incremental treadmill tests (at the beginning of
TP-1, and at the end of TP-1, CP-1, TP-2, CP-2). The IAT was calculated at LT+1.5mmoll-1 lactate. The training contents
were analyzed individually for each athlete.
Compared to the initial value the running speed was significantly higher for T at IAT for all further measurements. IAT
values changed significantly in the trained group only. TP-1 and TP-2 showed the highest increases for IAT. The weekly
training volumes for T during phases TP-1 and TP-2 were not significantly higher than during CP-1 and CP-2. This was
also true for the training volumes for the individual intensity domains, with the exception of extensive speed training,
which showed a significant decrease in the phases CP-1 and CP-2 compared to the initial value.
Of the examined training parameters, only the volume of the extensive speed training varied significantly between the different
phases. The highest increases in IAT occurred following the training phases with the highest volumes of extensive
speed training. Increased volumes for these training intensities appear to represent an ideal form for increasing aerobic endurance.