Conducting Workshops are hands-on approach, develops facilitation skills & learning from users, stake-holders - which should drive in greater confidence against being better knowledgeable by reading and writing blogs. Definitely conducting workshops are +1 point ahead. You can compare it with it even writing research papers and presenting in front of audience, since all these activities will test yourself in wild, which will be likely appreciated, criticized and eventually one will know where they stand in true time. Its oozes lots of confidence.
Now Attending workshops will help to connect with people and its a good learning curve.But book reading is equally enough. This is not as effective to conducting a workshop. Since you are passive mostly. Book-reading will be +1, since you can gain whatever knowledge by this channel equally.
Certification vs Portfolio - If your portfolio really will be a selling point, along with wonderful communication and personal selling value will be better off, if one knows that will win them the job they want. Certification needs cost factor to be taken into consideration, so portfolio can directly sell your abilities. If your degree is not in equivalent with the market, then the Certification comes in play to get the first job. In a longer run - experience, portfolio building, research papers & conducting workshops will all show participation and passionate efforts of one. Its good as personal value and it does helps in create reputation. Nowadays being active in social channels also means that one is selling his/her ideas.