I decided to put together a quick list of dos and don'ts in response to some truly terrible posts and profiles I've seen recently on Twitter. These are profiles belonging to fitness "professionals" who no doubt are well qualified, very nice people and quite possibly great trainers and instructors. The thing is many of their potential customers will never find out how great they are as they will have been put off by what they see online.
1) A photo speaks a thousand words
In general terms it's a good idea to include a photo of yourself as people like to have a face to relate to and it makes the whole experience more personal. However, it should not be too personal. Photos or yourself in your underwear or swimwear will do little to help your business credibility unless of course you are a fitness model and at the top of your game. Potential clients don't want to be intimidated by you. It's also a thin line between showing that you are fit and showing off. No one likes a show off. Get an inexpensive commercial profile photo done with you wearing professional but well fitted fitness gear.
2) Who, what, why?
You only get 160 characters in your Twitter profile to tell people about yourself. Don't waste them talking about your hobbies and things you love. And especially don't use this space to tell people about your own weaknesses. For example, someone looking for help to get in shape and lose weight is unlikely to approach a personal trainer who says "...and I'm addicted to chocolate biscuits"! You need to tell them who you are, what you do and why they should use you. End of. You can build up more about your personality in your tweets. For example:
"I am a Personal Trainer and group exercise instructor in Poole, Dorset offering bespoke personal training and fun and dynamic fitness classes. Try for free."
3) Keep your personal life separate unless relevant
It's important to build up a bit of a rapport with your followers and to get across some of your personality. With this in mind by all means share in your achievements and the occasional bit of personal news. Don't tell people how many tequila slammers you knocked back on Saturday night before throwing up in the kebab shop. Also, be careful of Twitter conversations with personal friends as you can never be sure what they may say.
4) Avoid profanity
This should be obvious, but I see so much effing and blinding and this probably stems from it being an industry with a very young demographic. You wouldn't, I hope, swear in front of someone you have only just met... so don't swear in front of your followers and your potential clients and fitness class members. At the very least save it for your personal profile. The occasional "WTF!", "OMFG!" may be acceptable to express some passion in your tweet but use sparingly or it becomes meaningless, and even then... there's probably a better alternative.
5) Don't get dragged in
Don't get dragged into arguments, flaming, Twitter wars etc. It doesn't matter whether you are in the right or the wrong, all the arguing parties tend to look like idiots and there is no place for it in business.
6) Watch your opinions and how you express them
You are of course allowed to have opinions and post about them especially if they are relevant to the fitness industry. Passing comment for example on the food industry and the duty of care they owe the consumer with their sugar and additive policies would be fine. However, passing comment on all the "fat arses hogging the equipment" you saw in the gym tonight is unlikely to win you any "fat arse" customers, and may well lose you some others.
7) Positive mental attitude
Be a positive influence rather than a "moaning Minnie". It's fine to have the occasional whinge about something (did I mention the food industry and sugar?) but don't moan in every post. You need to be seen as a positive bucket of energy constantly overflowing that positivity to the people around you, rather than someone that sucks the enjoyment out of life.
8 ) The key is the detail
When you are tweeting about your classes remember the "when" and the "where" again! Include the times of the classes and their location including the town name. Make sure you hashtag keywords as well like the type of class, e.g. #Zumba and the town, e.g. #Poole. By including the details, your followers (including @Fit2BFitsocial) are more likely to retweet you; and by including the hashtags you are more likely to get found and retweeted by non followers such as local event guides.
9) Tag @Fit2BFitsocial
If you include all the details above and include "@Fit2BFitsocial" in the tweet we'll gladly retweet your class information, and if you're members of the site we'll include a link to your class information on our site as well so people can get even more information about you and your fitness classes.
Keep training; keep smiling 
Mike