There are lots of programs that run 6-7x a week. Tempo running, for some people, can be very therapeutic. If the work is done on soft grass, then I don’t think there are necessarily any problems.
Please explain how tempo running even if it’s done on the soft grass can be very therapeutic? Is it b/c of less impact? Should speed not exceed 75% max? If it’s done on the grass barefoot then I see purpose of strenghtening foot muscles and reducing chances of injuries around it, but don’t see any links how it improves recovery after intense training sessions before the next quality session. I do tempo running as well but not for therapeutic reasons or better recovery, but for maintaining/improving my fitness, helping to control body fat level. If my aim would be to recover as quickly as possible so I would choose complete rest, some swimming or jogging at best. I know sprinters don’t like slow running or jogging and maybe there is no much place in sprinters program. But I guess from my experience that if you feel heavy or sore after couple of intense days in a row, plus you get some central fatique not just local muscular so sometimes better option is simply jogging, keeping heart rate low, some blood flowing into muscles and allowing to rest for faster muscle fibres. However, pool could be even better option b/c it’s non weight bearing activity. Many great 800m runners use jogging for regenerative purpose after intense training sessions, as some say almost at walking speed. However, many sprinters think that any slow running will slow them down even if it’s done for a short duration.