More specific training to increase fitness.
If there's one thing I hear from cyclists more than anything else, it's "how can I buy myself into being faster?". If "fast" means anything to a cyclist, they're going to have to suffer, or at the very least be uncomfortable during specific sessions. Fitness, especially high levels of it is one of the last few fair things on earth. You can't buy it and no one can give it to you. You have to go out and earn it while fighting the natural human tenancy to take it easy and be comfortable.
If someone wants "fast" and isn't good with the work it takes to get it; it's time for goal re-adjustment.