I'm a 40 year old man who manages to maintain a basic level of fitness. Most days I do a couple of sets of press-ups, walk my 10,000 steps and cycle a couple of miles. But I'm not kidding myself that I'm anything other than one step above "totally unfit".
In the years before children, I regularly hiked, scrambled and hillwalked. That's all gone by the wayside now. But I'm hoping that in a few years, when I have more free time, it'll become a possibility again. But I'm worried that if I don't keep up a minimal level of fitness, I won't be able to "re-train" my body when I hit 50.
I'm very busy, and I don't have much time to devote to fitness. Joining a gym is out of the question, as is devoting more than 10-15 minutes more than I already do to fitness.
What I'd like to be able to do is get up earlier and fit in some exercise before everyone else in the house is awake. It seems a good time of day to do it: get the blood flowing, enjoy the benefits of heightened metabolism, get the pain out of the way. But in order to do this, I have to be quiet so as not to disturb sleeping children. So it can't involve any vigorous activity like star jumps, or step-ups.
I also have no specialist equipment - not even free weights - and there's not room in my house to store anything bigger than perhaps a wrist-strap weight. So unless someone's starting making weights out of the hearts of neutron stars, it's body weight only exercises.
So my question is this: if I do 10 minutes of quiet bodyweight-based exercises like press-ups, planks or wall sits in the morning, is it going to be valuable for my strength and fitness? And if so, what quiet exercises should I be trying to fit in to those 10 minutes for a decent round-body workout?