"Children should not be long confined within doors, nor should they be required to apply themselves closely to study until a good foundation has been laid for physical development. For the first eight or ten years of a child's life the field or garden is the best schoolroom, the mother the best teacher, nature the best lesson book. Even when the child is old enough to attend school, his health should be regarded as of greater importance than a knowledge of books. He should be surrounded with the conditions most favorable to both physical and mental growth. Ed 208.1"
"Train up a child in the way he should go: and when he is old, he will not depart from it."
While Proverbs 22:6 focuses on moral training, the EGW passage discusses the importance of physical development and outdoor learning in a child's early years. There's a possible connection in the sense that both passages address the upbringing and education of children, but the specific focus differs. EGW's emphasis on physical development as a foundation could be seen as a way of 'training up a child in the way he should go' in a broader sense.
"The child is not alone in the danger from want of air and exercise. In the higher as well as the lower schools these essentials to health are still too often neglected. Many a student sits day after day in a close room bending over his books, his chest so contracted that he cannot take a full, deep breath, his blood moving sluggishly, his feet cold, his head hot. The body not being sufficiently nourished, the muscles are weakened, and the whole system is enervated and diseased. Often such students become lifelong invalids. They might have come from school with increased physical as well as mental strength, had they pursued their studies under proper conditions, with regular exercise in the sunlight and the open air. Ed 208.2"
"What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own?"
Both passages address the importance of caring for the body. The EGW passage speaks of the physical consequences of neglecting health, while the verse from 1 Corinthians speaks of the body as a temple. The connection is thematic, but not a direct principle or explicit allusion.
"The student who with limited time and means is struggling to gain an education should realize that time spent in physical exercise is not lost. He who continually pores over his books will find, after a time, that the mind has lost its freshness. Those who give proper attention to physical development will make greater advancement in literary lines than they would if their entire time were devoted to study. Ed 208.3"
"For bodily exercise profiteth little: but godliness is profitable unto all things, having promise of the life that now is, and of that which is to come."
The EGW passage directly contradicts the common misinterpretation of 1 Timothy 4:8. While Paul says bodily exercise profits 'little' compared to godliness, EGW argues that physical exercise is essential for mental and spiritual well-being, which is a direct application of the principle of caring for the body.