I have just run 12k for the first time (Yah!). A few days later I ran 5k, but ran it a bit fast (for me) and I pushed it a bit at the end so I was sweating and had monetary near dizziness. After I stopped I felt tired but ok.
Then I looked at my HR chart and wondered what was hell was happening at the end. First I though it was Hr strap dropout, but they normally happen as spikes and these are bursts of high hr lasting up 12-15 seconds. Is this what my heart was doing or should I think that the monitor has messed up?
Anybody got any ideas?