Do you think staff training should be fun or very professional?

When you say the word staff training we should 1st take into consideration what sort of training and what are the requirements and the prospective to it.  But just to answer on general basis few aspects need to be professional and on the other hand its always good to add in some activity and some fun to keep in the focus. Its physiologically seen that being too much into the subject makes it less interesting and loose focus.  Hope that is clear enough :)

"fun" and "professional" are not mutually exclusive. Training should certainly be professional in the sense that it addresses the needs and the objectives set forth and where its main focus is to develop the skills and/or knowledge of the trainees. That being said, there is no harm in incorporating some fun activities that break the ice, help the trainees relax and enjoy their sessions, and ultimately give them more focus and interest in the topics of the training program. Professional can be fun and fun can be professional. 

From my experience in training, and in teaching as well. I think it should be both, the methods and the techniques should be varied so the training won't be boring and loose its impact, the trainer should use activities relevant to the topics and meet the objectives.   

All work and no play makes the training Boring! Hence, it must be a healthy mix of fun (energizers, activities, video playbacks, etc) and delivery of hard professional inputs in a friendly and engaged environment!

Yes staff training is surely very professional and its a recreational activity on its own. In trainings people get time to intract with each other and get a break from their daily routine work. Most importantly they get to learn new techniques and technologies.

it should be in both ways theoritical and practical ways .. as john dowe said the learner shoud experince the new knowledgث

Trainings in all aspects must be in a professional way but adding fun on your training would be beneficial too. Too much seriousness on a particular thing can really be very boring and this could be applied to any classroom discussions or trainings. But why do we really have to choose in any of this too if we can have both in one training? 

Staff training should be more effective if it is delivered on a professional ground by stating out the areas that needs improvement, how it will be conducted, what are the needed resource, who will deliver the training, factors to determine the effectiveness of the training and lastly the feedback both from the trainer and trainee.

Being a trainer thoughout my professional career, i believe training should be professionally fun i.e. trainees will not be enthusiastic if training sessions are dry and dull. Few employees respond to or remember complicated concepts or theories; they want to learn practical information about what they can do to get better results today. If they don’t find the message entertaining, they won’t retain it. Since variety is the spice of life, use several different training methods to engage trainees in a variety of ways. Also work to alternate the pace of each session to keep trainees’ interest level high

I think it all depends on the training you are providing. In my experience in the hospitality and telecommunications industries, training was done in teams. With this in mind it was always good to make sure there was a balance of professional yet fun hands on activities to keep everyone engaged throughout the sessions.