No reason a 1h + shielder can't also go for high athlethics.
I'd go for 6 str at first, get some nice scimitar (speed 101!) or other weapon (also consider weapons that do blunt or pierce damage, like a winged mace or a pick), then get agility up and just max out athlethics, shield, weapon mastery and power strike. Excess skillpoints go in ironflesh for a bit of extra hitpoints. Maybe convert two skillpoints, so you'd end up with like 12 str and 24 agi.
That would allow you to get this build:
Level 30 (4 420 577 xp)
* Strength: 12
* Agility: 24
* Hit points: 55
* Converted: 2
* Ironflesh: 4
* Power Strike: 4
* Shield: 5
* Athletics: 8
* Weapon Master: 8
* One Handed: 173
That woudl work fine with a sword. You'd have the occasional glancing blow against heavy armor though. With this build you might switch some points from ironflesh and / or weapon mastery to shield though.
Even more extreme would be:
Level 30 (4 420 577 xp)
* Strength: 9
* Agility: 27
* Hit points: 50
* Converted: 2
* Ironflesh: 0
* Power Strike: 3
* Shield: 9
* Athletics: 9
* Weapon Master: 8
* One Handed: 173
You can go for 4 shield skill and the rest in ironflesh for more hitpoints or go for maximum shield skill and no ironflesh if you want your shields to break less and have better coverage. High shield skill is often worth it though.
With low strength, blunt or pierce weapons are nice, because they won't glance as much against high armored targets. Both builds have very high wpf and should be able to 'outswing' most other players, if you use a very fast weapon. Speed 99 or better recommended.
The trick with these builds is footwork. Move forward when you swing, but if you use a sword, make sure you hit at the extreme end of your weapon range to reduce the risk of glancing blows against heavy armor. And go for headshots.
Happy hunting!
Edit: Indeed, 9 shield is probably better than weapon mastery 9. Fixed it.