Don’t cling to old ideas about exercise and diet. Many of us grew up in a time when women did not lift weights. We took up yoga and pilates because it was considered more feminine. I did this myself and while I still love yoga, my body changed and I needed something different. We also may have grown up thinking smaller is better and so eating very little or being so strict about our diet was the way we thought we needed to live. This becomes unsustainable in the long term and is the reason most diets fail.
This brings me to eating enough to fuel our bodies. If you want to gain muscle, you need to eat! If you are exhausted and your energy is low from not enough fuel, it is unlikely that you will be able to train as hard as you need to in order to create adaptations.
Lifting weights is not rocket science but you need to learn good technique and form to not only avoid injury but in order to make progress. Get a private coach or join my Strength 101 class!
Most of us are not really eating enough protein and protein is the building block of muscle. As we get older this becomes more important as we are less able to synthesize the protein we do eat. I think we also have a natural decrease in our appetite as we age – I saw my grandmothers start to live on tea and toast. This is a recipe for frailty.
 You build muscle after you are finished working out- not during! Recovery time is so important. This doesn’t mean just lying on the couch (although there is nothing wrong with that!) Take days off to do light yoga, mobility work and lots of walking to stay feeling loose and injury free.