The anaerobic threshold (AT), the point at which lactic acid starts to accumulates in the muscles, is considered to be somewhere between 85% and 90% of your maximum heart rate (HRmax) .
Ultimately, Windows Defender might fail to update the definitions itself for whatever reason. In such cases you must either force a definition update by navigating to the designated tab of Windows Defender or by downloading and installing the latest signature definitions. The Windows Defender Definition Updates are offline packages containing the most recent antivirus signature for Windows Defender. Once installed, they will make sure your PC is safe from the latest known viruses, spyware, PUPs, and malicious files.
However, the following conditions must be in place: System Restore Point must have been turned on before you were infected with the malware. You must already have detected and removed the malware, and there can be no traces of it on your PC. You can use Windows Defender Offline to fully clean your PC. Your files must be on the same PC you're using to recover them (they can't be on a network or removable drive).