The plank exercise is no joke! The good news for expediters is it can be done in any truck or van as long as adequate floor space exists. Start where you can and build from there the length of time you can hold a plank.
Planking engages your upper abs, lower abs, obliques and lower back all at once. The benefits of strong core (mid body) muscles are numerous; especially in trucking where core strength protects the lower back and helps keep you safe in the day-to-day tasks truckers do. See:
The real-world benefits of strengthening your core.
At our gym, new personal training clients do a plank to gauge their core strength. It is quite surprising how much people vary in their ability to hold a plank. There are seemingly strong men who cannot hold a plank for 20 seconds. There are old ladies who can hold a plank for two minutes or more.
Give it a try. For most people, it takes only a minute or two. Plank once or twice a day for ten days and notice the results. If you have not planked before, you will be surprised by what you see and feel.
Here is a photo showing
proper plank form. Pay special attention to the upper arms. Notice how they are at right angles to the floor and are positioned straight down from the shoulders.
Here is
a video about 71 year-old Betty Lou Sweeny who, through exercise, lost over 100 lbs., moved from taking 26 medications to just one, and came to hold a plank for over 30 minutes.
For you personally, it does not matter how long you can hold a plank compared to other people. It matters only that you increase your time bit by bit to build your core strength.