Failed spencer +2

Last 5 weeks I have done a mix of SSMV2 which has gone really well. Have gotten up to 2 x 30min SS intervals at 90% ftp and raised some of the shorter vo2 stuff as the weeks went on, also done spencer+2 a couple of weeks ago at 117% of ftp which i was happy with. Got up today on my 40th birthday!!!, good nights sleep, good breakfast, normal resting HR so decided to do spencer+2 today and failed half way through the 1st interval!!!. What the hell…Only thing I can think off is I done a 20mins run yesterday evening and stopped with stomach pains but was grand afterwards but just a little bit of a sick feeling. Just curious to know if anyone has had a similar experience for a similar reason. Thanks.

If you not so long ago finished Spencer +2 at -3% and are otherwise doing fine, failing halfway into the first interval isn’t normal.

Sort of. Went for a short, easy run one day and felt tired and “off” that afternoon. Decided to try the bike workout anyway. After one interval of Carpathian Peak +1 at -5%, I knew I couldn’t continue that. Tried to do some of Carson at -5% and only made it through a couple of intervals. Woke up the next morning with the flu.