For calf strengthening I would do single leg calf raises - use a little support if needed, stand on your weaker leg and push up on your toes. Repeat until the calf is tired. You can also do this with the knee flexed around 30 degrees to target soleus or over the edge of a step to work a greater range of movement.
Ideally you do around 3 sets of around 25 reps (with 1-2 minute rest between sets).
Hi hot fox,
I would favour running over the lamp. There is a lot of research supporting the benefits of exercise on mental health as well as its physical benefits. I speak to lots of runners who have found running has transformed their mood and personally I find it excellent for managing my anxiety. If you run in daylight (such as in your lunch break) surely that would have the benefits you'd expect from the lamp anyway?
From personal experience I find it helps to add some work on how you think and feel as well as exercise. Things like CBT can be very helpful and Mindfulness is quickly becoming one of the top treatments for mental health. There is a free online CBT site that's good- llttf.com and the mental health foundation website is excellent - it includes some free relaxation podcasts that I've found incredibly helpful in the past - mentalhealth.org.uk. There is also an excellent long running forum on here about mental health and running you'll find lots of support there!
Hope that's helpful
Do not despair - most cases of PF do settle in time. What shoes are you running in at the mo?
Also do you do specific stretches for the plantar fascia and foam roller the calf? Both will help. Most people stretch the calf muscles - which is a good idea - but many don't realise that calf strength is also important in PF. Strong calf muscles can help reduce some of the stress on the fascia during impact. If you haven't already I'd add calf strengthening to your stretches too.
Hope that helps
I'm currently treating someone who developed PF trying to transition into barefoot running - I wouldn't assume it'll help your PF it could well make it worse. There are a few things to consider and really it depends on the cause of your PF.
In most cases of PF the plantar fascia becomes overloaded. The question is then why is the fascia being overloaded? It can be because of tight or weak calf muscles, poor foot posture, excessive mileage, poor movement control etc. Simply changing to barefoot running without addressing these wont deal with the cause.
The shoe vs barefoot debate is a huge topic and one technique won't suit everyone or every situation. Barefoot runners tend to forefoot strike which places greater load on the calf and Achilles. The Achilles blends with the plantar fascia so this could increase load on that too. Stability shoes tend to have a well developed arch support which can place pressure on the plantar fascia and irritate it as well. Sometimes the best solution is a neutral or stability shoe with a lot of cushioning to prevent this. I have seen some success with the Hoka one ones with PF in ultra marathon runners. That said it depends very much on each individual.
The research behind management of PF supports calf stretches, plantar fascial stretches and calf strengthening but currently there is little or no research on shoe selection or barefoot running. Personally I would try established treatments first and be very cautious about the barefoot approach. I wouldn't rule it out, but neither would I expect it to be a cure.