Well, YS284 states that Biomancy can be used to "supercharge" body attributes such as strength, speed, etc, though it suggests that physical consequences are a common side-effect due to (for example) the muscles making promises the skeleton can't keep. A bit later on YS287, it indicates that Psychomancy can do the same thing for mental abilities, with similar side-effects.
As far as difficulties, the only example I can find is the Escape Potion. This uses the 'simple action' option for Thaumaturgy, which (if I understand correctly) basically translates complexity into an effective result on a simple action. Based on this example, if I wanted to get enough biomantic strength to lift a midsize car (requires a +9 might result), this would be a complexity 9 spell. For simple action-flavored thaumaturgy, I think the duration is long enough to perform the action, which probably means an exchange or two, or *maybe* a few minutes, though it could be bumped up by adding shifts dictated by the time chart. Using Biomancy as Evocation, this would be one exchange, plus an exchange per shift paid to increase duration. Based on the side effect discussion, a GM might *require* that a consequence be part of the payment for the spell.
This doesn't really answer the question, though, which is how to use Biomancy to grant refresh-grade strength, speed, and toughness (Recovery is largely covered by the sample healing spell provided, which downgrades consequences much like Inhuman Recovery). Some aspects of this are on the easy side (toughness is mostly an armor effect; in this case you're using Biomancy insead of Spirit to generate the effect), others less so.
