Missing training at some point is inevitable. Whether it’s work or family commitments or a niggle or illness the odd missed training can’t be helped and sometimes can benefit you in the long run to help freshen you up and get ready for your next key session.
You can either move your sessions around within a given week or just accept it as a missed session and move onto the next one.
If you are injured and have doubts we always recommend seeking the advise of a medical professional. Likewise if you’re sick taking some time off is always preferable to recover and prevent missing further training.