Once you have acquired NFT Sneakers, you will receive daily energy, which will determine the maximum time you can train and earn. Once your energy is depleted, you will not be able to earn anything even though you can continue your training.
During the closed Beta of the app, you'll get 30 daily energy points, which is basically 30 minutes of workout (1 energy = 1 minute). Energy will be provided to you for many periods of time - 10 energy per pair of sneakers you own for every 8 hours.
If you want more energy, you can buy it back for 20 MEG for 30 energy. You are only allowed to redeem once per day for each pair of sneakers you have.