Fitness Friday | The 9 Steps of Creating an Unhealthy, Unsafe Driver

In the first week of a driver’s career, stress of learning how to drive a truck and starting a new job increases cortisol levels, initiating the first hormonal change.
In the next two to four weeks, the irregular sleep schedule combined with interrupted sleep results in accumulated sleep deprivation. After just four nights of sleep deprivation, insulin sensitivity drops by as much as 16% and fat cell sensitivity to insulin drops by 30%. This is the equivalent of metabolically aging someone 10 to 20 years just from four nights of partial sleep restriction.
After four weeks of passively sitting in the driver’s seat during a regular driving shift, the hip flexors tighten and shorten, causing bad posture, improper force loading on joints and ankle, knee, hip, lower back, neck and shoulder injuries.
After three months, the driver’s serum leptin and serum ghrelin levels have been altered and the driver’s body is unable to regulate hunger properly. Glucose reserves in the liver and muscle are full and the body can only store consumed carbohydrates as fat.
By this time, the vast majority of drivers start skipping meals in order to keep the truck rolling. As the body goes into starvation mode, low leptin levels signal to the brain that the body needs feeding. Energy expenditure is reduced to compensate for the lack of food intake, thus lowering metabolism. This creates a hormonal environment conducive for storing fat. Thyroid hormones fall, while cortisol and ghrelin hormones rise. The combined effect of these hormonal changes is lower metabolism and increase in appetite and fat storage. So the driver both starves himself and over-eats when he finally does get a meal.
After six months on the job, the driver has gained significant body fat while losing lean muscle. This decreases the body’s ability to extract oxygen from the blood at the cellular level for the aerobic production of ATP which is the cell’s usable fuel for producing energy. The result is that the driver feels more fatigued and has less energy available for activities of daily living and truck driving.
From 6 months to 1 year, a truck driver has now gained 7% of his body weight and 1 inch to his waist. He has increased his risk for 60 medical disorders including 12 cancers. Specifically,
Blood pressure increases by 10% (30.5%)
Blood cholesterol level increases by 8% (28%)
High Density Lipoprotein (HDL) decreased by 15% (52.5%)
Triglycerides increase by 18% (63%)
Metabolic Syndrome risk increases by 18% (63%)
Once the driver becomes “obese” – that is, their BMI is over 30.0 – then average driver in America (69%) has a three-fold increase in the above numbers (above).
Once the driver is obese, he has a 20% to 30% more likelihood of developing severe obstructive sleep apnea and once that happens, the driver has a 7-fold increased risk of being involved in a motor vehicle accident and causes 455 more accidents per mile driven than non-obese drivers with no sleep disordered breathing.

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