Now that you've got your sportswear covered, it's time to bust out the big guns -- namely, the training gear that will have you sweating and feeling the burn while also conveniently fitting into your backpack for easy transport.
A heavy rope is a must, per Esquire. Go for one with a weight option, such as the Get Strong Rope, to really get those muscles working.
If you're used to sweating it out with your TRX system at home, the good news is you can pack it up to go as well. All you need to do is hook it up to something sturdy, like a tree branch, a metal pole, or a tall grill fence. If you don't have a TRX system already, pick one up here.
If you want to go that extra mile and truly intensify your cross-training, strength training or running regimen, consider wearing a weighted vest, that you can fit with a variety of weights as desired.