Encumberance is a major deciding factor to survival. Encumberance is only calculated by all your weaponsa and armour slots, so if you only use one weapon say, big mutha axe or sword and maybe a shield with one hander, take the other slots out, and you can reduce about 6-10 in weight. This will speed you up dramatically.
A slight cheat i have found with archers. You can be untouchable if your armour is light enough and your athletic. When an enemy approaches with shield raised draw your bow while bachpeddling, then stop. All enemies must lower their gaurd to attack, as soon as he does he will find a high powered arrow lodged where he used to think that charging you was a good idea