Use a Backpack to Build Strength
It may sound strange, but a backpack can really help you to get in shape without spending money on weights or the gym. Wearing a backpack is an easy and safe way to add greater resistance to workouts. Training using a backpack will also prepare you for any backpacking excursions that you may foresee in your future or any survivalist safari that you need to undertake. If those things are unrealistic, a backpack will also prepare you for the regular daily strength needs.
Filling the Backpack
When filling the backpack, be careful not to overload one side or area, as it may cause strain and possibly injury. Fill the backpack with about 15 to 30 pounds of soft gear, for best results. As your resilience increases, you can increase the weight.
Once you have the backpack loaded up and secured on your back, you can perform normal exercises with the additional weight on your back to add resistance. To do weighted planks, simply lie on the floor on your forearms and toes with the backpack on your back. Hold your core muscles tight and avoid letting your middle sag. Hold the weighted plank position for about 20 seconds initially, gradually working up to 60 seconds.
Weighted jogging will help you train like military personnel. Simply jog as you normally would after ensuring that the backpack is securely in place. This will help to strengthen your shoulders, chest, and back in addition to your legs as your body supports the extra weight.
To add a level of difficulty to your lunges, do them with a weighted backpack on. By careful not to lean forward while lunging as you normally would. The extra weight may put greater strain on your back if lunges are done improperly.