IP SLA (Service-Level Agreement) on Cisco IOS

Hi Rene,
sometimes I saw the log output below in my router log, and experience a slowness in the network, could you please explain it to me and what to look for.

Feb  4 08:00:39.636: %TRACK-6-STATE: 11166 ip sla 11166 state Up -> Down
Feb  4 08:00:40.548: %TRACK-6-STATE: 1116 list threshold percentage Up -> Down
Feb  4 08:01:24.636: %TRACK-6-STATE: 11166 ip sla 11166 state Down -> Up
Feb  4 08:01:25.576: %TRACK-6-STATE: 1116 list threshold percentage Down -> Up
Feb  4 08:45:29.659: %TRACK-6-STATE: 11161 ip sla 11161 state Up -> Down
Feb  4 08:45:29.659: %TRACK-6-STATE: 11162 ip sla 11162 state Up -> Down
Feb  4 08:45:30.107: %TRACK-6-STATE: 1116 list threshold percentage Up -> Down
Feb  4 08:45:54.659: %TRACK-6-STATE: 11166 ip sla 11166 state Up -> Down
Feb  4 08:45:54.659: %TRACK-6-STATE: 11164 ip sla 11164 state Up -> Down
Feb  4 08:46:19.659: %TRACK-6-STATE: 11161 ip sla 11161 state Down -> Up
Feb  4 08:46:19.659: %TRACK-6-STATE: 11162 ip sla 11162 state Down -> Up
Feb  4 08:46:24.659: %TRACK-6-STATE: 11166 ip sla 11166 state Down -> Up
Feb  4 08:46:24.659: %TRACK-6-STATE: 11164 ip sla 11164 state Down -> Up
Feb  4 08:46:25.231: %TRACK-6-STATE: 1116 list threshold percentage Down -> Up

Thanks in advance.