26 is a perfectly fine age to start building your body.
You can start at any age and it's not about accomplishing something, just offering your body a specific amount of aerobic and resistance training workload.
You don't owe this to anyone and you don't need to measure up to anyones standards, just do what feels reasonable to yourself. I was above 30 when I started regular exercise regimen. You don't need anything complex. If someone is trying to sell you up to something complex and expensive, skip it (unless you find it personally motivating). What one does need, is a routine.. I do running, kettlebells and pushups. I hate every minute of it, but luckily podcasts, audiobooks etc. make the exercise go past unnoticeably. I do it because if I don't, my body will start to punish me with various aches and pains.
The best long distance runners, the Tarahumara, got brought to races. The first they didn't do well because they were forced to wear the shoes of the sponsor. The second time they could run barefoot like they used to, in a cutout from an old tire with a cord pulled through. The 60 year old won handily. Source: Born To Run by Chris McDougall. Highly recommended, devoured it.
It's just fascinating that people can live to 80 or more and still be moderately healthy and physically fit enough to run as this guy in the article, that's all.
Since then I've started skiing, climbing, and running regularly, and there are a number of benefits that I've noticed:
- Great social outlet
- As you do it more and more, pushing yourself, and competing is quite fun
- I used to have back pain and other issues - being active has definitely helped with that
- It helps regulate my mood