I enjoy my mate but I really enjoy my alone time as well. How important is it for couples to do things together? 

It is important for couples to do things together to strengthen and build a relationship; this also promotes growth in the relationship.  When you learn new things together, it is exciting and promotes commonality and talking points. You will learn to enjoy each other and do things together. On the flip side, constantly doing things alone can lead to your partner getting used to doing things without you or being used to experiencing new things without you. This can lead to single-like behavior.

I desire to live a healthy lifestyle. What can you suggest to help?

This should be a long-term goal and not just for the warmer seasons or for a special event. You should also meditate on health scriptures such as ones talking about your youth and health being renewed (Psalm 103:5) or the 120 year life span scripture (Genesis 6:3). Moses was a good example; when he died, his eyes were not dim and his natural forces were not abated. When you with meditate on the scripture, it will produce an inner image on the inside of you. It will draw you to a healthier lifestyle and lead you to making healthier choices.