The confidence you gain from fitness and good health helps you in work situations for sure. People notice your energy and respond in a positive way. It helps if you are outgoing and people-friendly.
It depends on the work environment, but appearance can help you too. Where is your consulting firm? If you wear quality, well-fitted business attire, it helps. Being fashionable and stylish can work against you if you appear to be too much the peacock.
It's funny, when I got out of college, I was sort of a hippy. But I set up a screen-printing business in Eugene and wore button down oxford shirts, new Levis and leather oxford shoes. People trusted me even though I was only 24. I was able to build a business and succeed. This is the early 1980s during a horrible recession, but my shop took off. I've long since moved on, but it was great fun.
I was 6'1" and weighed 155. Slim, but not small.
Anyhow, good luck. Look sharp, take care of yourself, and be confident.