Our overall environment is training us on habits that are easy to train: sit down, eat, consume media. Mark created a micro-environment around himself (Noom, Peleton, accountability partners, etc) that trained him into harder (but healthier!) habits.
Consumers paying for tech that trains them in the direction they want to go is a huge market opportunity for the next decade. The killer App will be a sticky, integrated system rather than the multiple systems Mark has had to string together.