Yes, biking. But no other training on a Friday night, so why not cross-train with 2000-3000 others at the “San Jose Bike Party!”?
3rd Friday each month http://www.sjbikeparty.org/ and https://www.facebook.com/sjbikeparty it's a fun social ride that can be aggressive or laid back. A (dis)organized Tour de Silicon Valley: a different theme announced far ahead of time, and a different route announced 24hrs before.
A flat ride 18-28 miles, with 2 stops in the middle (I’ve seen bike jousting, and gotten free hot dogs & condiments charcoal roasted on a small Webber a stranger strapped over his rear wheel). A generally wholesome memorable ride of Americana (unlike SF’s Critical Mass, SJBP! cooperates with police/gov’t/traffic), seeing the streets & neighborhoods from a different vantage point, around others yelling “Bike Party!”, trussed up with a costume, or pulling a sofa with their bike.
Bring your bike, friends who are 8 to 88, snacks or a few $$ for food trucks at the breaks … and a wheeled sofa if you have one.