I recorded this walk using a DJI Osmo. The distance of the walk is 3.2 miles from the Andaz hotel to the Fairmont hotel and return on the Wailea Beach Path on Maui. Going to use this on my treadmill in winter!
The entire recording at 4K was 21GB for 47 minutes of video. I found no problem with battery life. Worked just fine. Holding it while walking was easy and not uncomfortable. I used an iPhone 5s.