Backpacking is hard work! I'd just say that my wife and I train for our longer trips, often putting in lots of road miles when we can't be out on trails. You don't have to have single digit body fat and look like your ready for the Olympics, but some degree of fitness is a necessity. Carrying a 40 lb. pack over rough terrain is asking for injury and misery if you aren't in the required shape for it. Logs set like steps sound like an easy obstacle; you're fighting gravity sounds like the real barrier to having fun . You can pair down your pack weight with some investment in lighter gear- I'm down to about a 28- 30 lb. winter pack, but taking weight off your frame will be of far more benefit. If you really want to pursue backpacking, pick some easier, flatter trails that are more in line with your level of fitness. As you gain in ability, chose harder terrain. After a near lifetime of backpacking, it's easy for me to evaluate my abilities to negotiate any given trail or terrain conditions- you may wish to ask about specific trails and their difficulty levels before attempting them. If you don't use trekking poles, they may benefit your comfort level on the trail, too. Worth looking into their use .