[Effect of intensive motor activity in different periods of time on the human functional state and efficiency] Aviakosmicheskaia i ekologicheskaia meditsina = Aerospace and environmental medicine [Aviakosm Ekolog Med] Journal article

Effects of heavy physical work on gas-energy exchange, cardiac activity, thermal condition, nervous system and the subjective status were evaluated in 43 athletes in the morning, afternoon and evening. It was shown that same muscular work done at the ambient temperature of 17 +/- 1 degrees C, relative humidity of 65 +/- 3% and air flow of 0.3 +/- 0.1 m/s requires a significantly higher straining of the body functions in the evening hours (after 06.00 p.m.).

Aviakosmicheskaia i ekologicheskaia meditsina = Aerospace and environmental medicine [Aviakosm Ekolog Med]