I know it has been a long time without access to the gym and we are dying to get back in and start training again. I also know there is a huge fear of losing everything we've worked really hard for. I am hear to tell you not to fear the science has shown in a handful of studies that muscular strength and hypertrophy does come back and faster than you think. In this study on elderly men by Taaffe D. and Marcus R. took 11 men aged from 65-77 years old and had them do a 24-week training program followed by a 12-week detraining block, followed by an 8-week retraining block. During that 8-week block they were able to match their previous strength. This is great news even though the population doesn't match the average reader, it is far harder to gain strength as you get older so if this population can do it, I think we are good to go.
Another study done in women by Staron and colleagues took 6 women and trained them for 20-weeks in their lower body followed by a detraining phase that lasted 32 weeks and retrained for 6-weeks. The data suggested that rapid muscular adaptations occur as a result of strength training in previously trained women. Some adaptations (fiber area and maximal dynamic strength) may be retained for long periods during detraining and may contribute to a rapid return to "competitive" form.
So do not fear whatever you may lose now will come back and at a very fast rate so focus on other dynamics of training to become a more well rounded lifter and take care of the strength when the gyms open back up.
Taaffe, D. R., & Marcus, R. (1997). Dynamic muscle strength alterations to detraining and retraining in elderly men. Clinical Physiology, 17(3), 311-324. https://doi.org/10.1111/j.1365-2281.1997.tb00010.x
Staron, R. S., Leonardi, M. J., Karapondo, D. L., Malicky, E. S., Falkel, J. E., Hagerman, F. C., & Hikida, R. S. (1991). Strength and skeletal muscle adaptations in heavy-resistance-trained women after detraining and retraining. Journal of Applied Physiology, 70(2), 631-640. https://doi.org/10.1152/jappl.1991.70.2.631
