Cowley (a retired lawyer) and Lodge (internist) tag-team as motivator and explainer for why and how our later years can be improved, and even better than our middle age.
Cowley's humorous and self-deprecating approach is geared to get the sedentary up off the couch. Most of the folks I know are already motivated, and though they may find his chapters entertaining, won't gain much real knowledge here. His chapters are a bit over half of the book.
The real meat of the book for me is Dr. Lodge's medical explanation (in easy-to-digest layman's terms) for why we degenerate the way we do, and how to prevent and reverse it.
The main advice (vigorous exercise, sleep well, socialize, be spiritual) isn't new, but Lodge's framing in evolutionary terms is quite good.
Decay and Growth.
Decay - When we damage tissue we produce cytokines (a diverse family of regulating proteins) that signal for decay and inflammation. The main decay cytokine-6 (C-6 in our notation - a gross but useful oversimplification). C-6 is stimulated also by stress, and increases in base metabolism as we age. Ergo, if we do nothing, stay sedentary, we make more C-6 and invite decay and inflammation. This is what has been considered 'normal' aging in our culture.
Growth - When enough C-6 is produced (some threshold a bit above base metabolism), it triggers our tissues to also make cytokine-10 (C-10), the growth and repair cytokines. C-10 helps not only repair the damage that has been done, but stimulates new growth and enhances the function of each system that has been stressed by C-6.
In order to get the growth and repair going, we have to push the body through vigorous exercise. The harder the better (within the normal caveat limitations of your doctor's clearance). When we do push the body, we produce an excess of C-6 which is made in logarithmic proportion to duration and intensity of exercise. C-10 is produced in response to C-6, but low levels of C-6 will not stimulate C-10; this is baseline decay.
The key: Inflammation controls growth. C-6 controls C-10.
Activity level and fuels.
Mitochondria burn either fat or glucose. At rest and during light exercise we burn 95% fat and 5% glucose. the fat is carried in triglyceride proteins (large - need more capillaries). Harder exercise now requires more glucose (=more capillaries, =muscle growth). p99
At about 85% MHR we reach the upper limit of aerobic capacity. Above 85% we go anerobic - we can double the power output, but only for about 10 seconds. We increase the heart's output four times over resting, and exceeds the body's ability to deliver blood and oxygen to the muscles.
Foods. Refining wheat (rice, grains) breaks down cell walls, and releases simple sugars. p.228
Three Brains.
Physical brain. (reptiles) sensation and movement. Reacts to stimuli. Most primitive brain.
Emotional Brain. Feelings and moods. Stronger than the rational brain: limbic wiring is physically stronger than
Thinking Brain. (mammals) Communicates - between beings, ergo a social brain. What is most easily communicated are emotions (see emotional brain!) - Limbic resonance is the unconscious synchronization between individuals by non-verbal cues. --Emotions are involuntarily shared in this way through pupil dilation, posture, etc.
The reptile is run by negatives (hunger, pain, survival). Mammals inverted the motivators and are run by positives requiring communication (hunting, tribe/pack behavior, foraging, making tools) with their social brains. We evolved requiring communication with each other - we need communication, we need emotional communication.
