Is it possible to build bigger arms without lifting weights? Umm, no. But there might be a way to challenge your arms without weights.
New research out of New Zealand shows that arm muscles (specifically triceps) work 30 percent harder during Swiss-ball pushups than during regular pushups.
Since the Swiss ball is unstable, your triceps have to work a little harder to stabilize certain joints; hence, more muscle fibers are recruited to perform a pushup with your hands on a Swiss ball.
Here is something else to keep in mind. While I do think that it is virtually impossible to increase the size of your biceps without lifting weights, you can indirectly stimulate your arms. Not only your arms, your entire body. How? Read the hex bar deadlift vs. straight bar deadlift post.
In other “workout without weights” news, researchers found that doing sprints on the days when you do not lift weights may boost your weight lifting performance.
The theory goes that sprinting closely mimics weight training in the way it conditions your cardiovascular system and your muscles, which enhances your ability to perform more sets and reps when you lift weights at the gym.
When you are not pumping iron, do at least four sprints twice a week: run as fast as you can for 15 seconds, rest for 60 seconds, sprint again for 15 seconds, etc.