so, i've noticed something strange: when i look at my hr rate analysis graph upon waking up, there's a brief spike. it occurs at almost the same time every night, give or take 15 minutes. between 1am and 1:30am, my heart rate jumps to 130+. i'm usually asleep, but i noticed it when i was awake at that time the other night. here's what's even stranger. the spike does not appear immediately. the other night, i went to bed at around 3am. before bed, i looked at my heart rate analysis graph, and it was flat -- no spikes. but when i awoke, there was a spike where there wasn't one previously (in that 1-1:30 timeframe). other times, i've noticed this: when i wake up, the graph looks normal (no spikes). but, when i again look at the graph later in the day, there is a spike that wasn't previously there (and in that 1am timeframe). any explanation?
