Canned Soups & Sodium

Would you please shed some light on the large amounts of sodium found in some canned soups? 

For example, I am looking at Trader Joes Organic Lentil Vegaetable Soup.  A 14.5 oz can is 2 servings.  Each serving contains 580mg Sodium.  I would eat the whole can as a small meal or big snack.  It's really just one large bowl. 

Is over 1,000 mg of sodium in one sitting way too much?   What would be a reasonable amount of sodium in a 14 oz can of soup?

The second part of this questions is:  If I am going on a long run tomorrow morning, is there any benefit by taking in more sodium tonight? (Like this can of soup)  Could this be harmful or helpful?

Many thanks,