old posts may lead to a duplicate contents and you can as well be penalize for it. However, the penalty can be avoided following these tips;
Update Old Content for New Realities
Look for evergreen or ever relevant posts on your website or blog for reusing. Blog posts that are relevant yesterday can still be relevant today. Blog posts relating to Traffic, SEO etc are evergreen and can still be reused and re-posted on your blog. However, it does not really make sense when you go on salvaging dead posts.
Convert Blog Posts into Infographics or Videos
Another way to get your blog post reused as newer posts is to change some of the old posts into Infographics especially posts with statistics that would be nice on graph, it is also possible to convert your old posts into videos or audiovisual media but you must have to include other new things or new fewer words alongside the infographics or videos. You must think of adding something significant to the infographics or videos.
Promote Reused Content
Having succeeded in converting your old posts into new ones, do remember to promote the post cause these changes are not noticed by your blog visitors except you create the awareness and by doing this more traffic are generated to your blog or websites. It is also important do don't neglect SEO practices cause it would help your blog or website a great deal!
Use old Posts as EBooks
Another smart way to reused your old contents is by creating an ebook with but in a unique manner so as not look like a copy and paste thing, the ebooks should be created in such a way that it would be valuable and useful to your readers.
Hope this help? Do share cause there is love in sharing.