“This brought me back. While I was doing my photo shoot this week for Muscle & Fitness, I could practically hear Joe Weider screaming, “Come on Arnold! What’s wrong with you? Pull in the stomach.” Watch for the issue in September!”

A leopard seal feeds Paul Nicklen a penguin. (Photo by Paul Nicklen/National Geographic). Antarctic Peninsula, 2011

A indigenous man from the Tabajara tribe is seen in Tocantins river before the I World Games for Indigenous People in Palmas, Brazil, October 21, 2015. (Photo by Ueslei Marcelino/Reuters)

Naturally, it is important that a baby learn the right habits. This woman demonstrates that smoking is wrong for babies. From a series of images parodying women's lifestyle and beauty magazines. (Photo by Jacobsen/Getty Images). 1955

A woman performs during a march to commemorate International Day for the Elimination of Violence Against Women, in Bogota, November 25, 2015. (Photo by John Vizcaino/Reuters)

Saraa Mutawkil (R), 18, practises boxing at Al Rabie club in Omdurman May 10, 2016. (Photo by Mohamed Nureldin Abdallah/Reuters)

The 33rd All Women Lifeguard Tournament held at Sandy Hook Gateway National Recreation Area in Sandy Hook New Jersey. Wednesday, July 26th, 2017 (Photo by Anthony Causi)

In northwest Russia, in a small village called Alekhovshchina, Nadia Sablin's aunts spend the warmer months together in the family home and live as the family has always lived, chopping wood to heat the house and making their own clothes. Sablin's book of photographs, “Aunties: The Seven Summers of Alevtina and Ludmila”, is published by Duke University Press. Here: “Two-Handed Saw, 2014”. (Photo by Nadia Sablin)