Finally, the type of exercise you do is the last part of the F.I.T.T. principle and an easy one to manipulate to avoid overuse injuries or weight loss plateaus. For cardio exercise: Cardio is easy to change, since any activity that gets your heart rate up counts.
First published in 1959, this pair of meditations by the revered civil-rights leader Martin Luther King, Jr. contains the theological roots of his political and social philosophy of nonviolent activism. Eloquent and passionate, reasoned and sensitive.
Books about culture and ecology began to emerge in the 1950s and 1960s. One of the first to be published in the United Kingdom was The Human Species by a zoologist, Anthony Barnett. It came out in 1950-subtitled The biology of man but was about a much narrower subset of topics.