By Dr. Justin Bland, chair of the department of exercise and sport sciences | excerpts from his presentation at Lectureship 2022 |
“So God blessed the seventh day and made it holy because on it God rested from all his work that he had done in creation.” —Genesis 1:5, 2:3
Why does each day begin with evening? What does it mean for God to rest on the seventh day? The word “blessing” is used twice in the first chapter of the Bible — first in verse 28, “And God blessed them, saying, ‘Be fruitful and multiply …’” Surely then the blessing of the seventh day is connected to life and abundance. On the seventh day of the week, Israelites were not to gather what they needed to live. They were to stop and rest. Sabbath is a regular enactment of this profound truth: God himself sustains creation. Anything we do in an attempt to control or provide life is ultimately an illusion. If we have been tracking with the biblical narrative, it should come as no surprise that humanity’s decision to ignore God, the author and source of life, and define what is good in our own eyes comes at our peril — exile and death. Rest, instilled by the almighty in the very fabric of creation, is generally believed to be unnecessary. We say we need rest, but our actions say otherwise.
Through the years, I have been trying to understand, practice and communicate how we can use our bodies to the glory of the king. A basic tenet of exercise science is that rest between exercise bouts allows for muscles to respond fully. But not just any rest will do. Sleep particularly promotes muscle growth. We all know sleep is important, yet we ignore it. We act as if sleep is a nuisance, something we “have to do,” “wasting a third of our life” doing nothing, just sleeping. These statements are the antithesis of the truth.
There are two phases of sleep: non-rapid eye movement and rapid eye movement. NREM sleep consists of four stages of increasing depth whereas REM is the lightest sleep and is marked by elevated brain activity. We cycle through NREM and REM every 90 minutes. Even though NREM has lower brain activity, it has been causally linked to brain development. In a study that prevented young rats and cats from NREM sleep, the brain stopped maturing. 1 Another study observed a reduction in NREM sleep decreased brain development of the frontal lobe, which is the area of the brain propelling youth into adulthood. 2 Furthermore, one study suggests that sleep disturbances and the subsequent loss of deep NREM sleep often precede the onset of Alzheimer’s by a few years. 3 The second phase of sleep, REM, is commonly known as the dreaming phase with reports of up to 30% more activity in REM than when we are awake. 4 It is during this time that the brain is attempting to find and make critical connections among all our waking experiences, which is absolutely essential, for example, to understand subtle facial expressions and to interpret social scenarios. Choosing to sleep less than we need has catastrophic consequences — exile and death.
Sabbath is more than sleep, but it is not less than that. Appropriate sleep is a gift from the almighty and requires us to stop what we want to do and “trust in the Lord with all our heart and lean not on our own understanding” (Proverbs 3:5). Obey the king, and he will bless you so you can be a blessing to the nations.
1 Frank, M. G., Issa, N. P. & Stryker, M. P. Sleep Enhances Plasticity in the Developing Visual Cortex. Neuron 30, 275–287 (2001).
2 Sarkar, S., Katshu, M. Z. U. H., Nizamie, S. H. & Praharaj, S. K. Slow wave sleep deficits as a trait marker in patients with schizophrenia. Schizophr Res 124, 127–133 (2010).
3 Mander, B. A. Local Sleep and Alzheimer’s Disease Pathophysiology. Front Neurosci-switz 14, 525970 (2020).
4 Walker, M. (2017). Why We Sleep: Unlocking the Power of Sleep and Dreams. Scribner.