Are the variable types here considered correct? If we want to determine the variable types, will it be as follows for the below variables?
Age ---> quantitative, discrete (we can count)
Fitness ---> If the values that we will enter here are 0 and 1 only, will the type of this variable be qualitative, nominal?
Thanks a lot.
 A: Questions like this expose the problems with Stevens' typology of variables. Some variables just aren't any of his categories; or are hard to categorize. Age is ratio level data in the sense that someone who is (say) 40 years old is twice as old as someone who is 20 years old. You just haven't got it measured precisely. But so? What difference does that make? 
Dichotomies - here it really doesn't matter HOW you treat them for most purposes. E.g. in regression, you can consider them to be nominal, ordinal or interval and you will get the same results. 
I wrote about other problems with this typology on my blog
A: It depends on requirements of software and specific procedure you use for the analysis. In general, I personally like to register binary variables (1=present vs 0=absent) as ordinal level, not nominal level, such as sex (1=male, 2=female). But is matter of taste and custom...
A: They could be as you wrote - but they might not.
Age could be either discrete (if you only count whole years) or continuous (if you allow someone to be fractions of a year old)
Fitness would probably be qualitative - unless you assess fitness through some quantitative test.
