Having played sports much of my life, I learned the value of stretching. I guess it was more important to me now, considering my age, but many of the young ones would walk crooked and constantly complain about back and other pains. Many say that two months is about the limit, but I believe that, with proper eating and stretching, one can sustain this activity for extended periods (my record was 8 months). It is more than a sport, which can last only a few hours and be granted several days break. To make good cash, you need to put in high numbers. At least 2000 trees a day, where each tree can require at least 4 movements of the arm and much clambering over logs. It could be similar to pushing and pulling hard on a lever 10,000 times a day, while walking several miles over various obstacles.
One night of sleep is usually not enough to compensate for such lengthy exercise, and the muscles can easily get bottled up. Especially because most planters use the same hand for the shovel, and the other hand to hold the tree. This creates a repetitive and unbalanced movement all day long, making the body crooked in the process. Anything like Yoga is great, but generally I like to stretch where I feel I need it the most. I would suggest you pay attention to your body and stretch out the muscles that are hurting you the most, but try to keep your body warm so you don’t lose too much momentum after a bagup. If you do not balance out your body by stretching and counteract the bottling, you may find yourself with permanent back pains or a contorted shape. Not to mention that things may add up too much and cut your season short with excessive pain. If in pain I would always stretch before planting, and often during bagups. Although you can overcome the pain with the adrenalin you generate while planting, I see how planters who dont stretch become increasingly disfigured and in pain over the season.