Writing this on the morning of the 15th February, 2014.  I am exactly 76 years old today.  Life goes on as usual.  Normal activity such early morning jog around 5 km, followed by light calisthenics in the room, with light weights of barbells and dumbells.  Feels good.  Nice to do physicalworkout and have a sweat.
Yes, to be healthy at this age is very important to me.  Always in my mind:  You must work hard for your health.  And that, is exactly what I always do.  And I love every moment of it.
There is another interesting phenomena that I noticed.  When I was 60, I could do the 10 km run in 60 minutes. At 70, the time taken: approximately 70 minutes.  Maybe when I am an octogenarian, I might be able to do the 10 km run in 80 minutes?  Hopefully so.  Its a target eagerly looking forward to.

As a septuagenarian, I like reading books on health, as to be healthy is the most important thing at this juncture of my life.  Recently I read this book: "Anti-Ageing Handbook" by Dr. Geraldine Mittons - New Holland Publishers (UK) Ltd. I particularly like this piece: What is youthful ageing?  Good health and youthful ageing have many dimensions.  This means having all your body parts in good working order; having a good memory, with precision in thought and action; having enough energy to enjoy physical activities; going to sleep and awakening easily; being able to laugh and be playful; being able to love and be loved; being able to enjoy the support of a wide circle of friends; being flexible and open to new adventures; being able to  appreciate the beauties of nature and the environment; having a purpose and meaning in life; having spiritual well-being etc, etc.

I feel inspired on reading this book.  It has lots of advice on keeping you healthy and to be healthy is my magnificent obsession.