Golden Rule of Tapering

My golden rule of tapering...

Only run at race pace or faster during the taper period

Everything else flows from this - Practical Tapering, The Science of Tapering & Tapering Tips

Tapering is all about recovering and healing. The benefits of longer, slower running to build endurance will not be realized within the taper period. It's okay to do a warm up at a slower pace, or to take Walking Breaks between intervals.