If I carry a backpack (inside put dumbbells) and go for runs around the neighbourhood...

[ThorOdinson]

How will it affect my physique, if at all?

 

[galapogos]

You'll probably lose weight if you do it frequently and regularly, and don't eat more.
You'll probably also get sore knees.

 

[striker22]

You probably get a sore back and or shoulders. Basically if the backpack flops around when u run, you are bound to get bruises.

The idea of adding weights when running is to keep the weights as close to the torso to reduce stress on the back or to add them to legs. Rather than dumbbells, you would want weight plates inside a very strong ergonomically design backpack ideally with a chest strap to keep the load evenly spread.

There are much better exercise options than this.

 

[ThorOdinson]

the reason why i asking is cos got someone around my block, i always see him running with a backpack..