The study conducted to discovered how or when to exercise are based on:
The study in question was conducted in each group to discovered how or when to exercise.
The observational study is one where the researchers observe the effect of a risk factor, diagnostic test, treatment or other intervention without trying to change who is while the time series study involves a specific way of analyzing a sequence of data points collected over an interval of time.
Both the first and second studies were observational and time series. The studies were observational because each group was not told how or when to exercise.
Hence, the study conducted to discovered how or when to exercise are based on observational study and time-series study.
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