In general terms, getting puffed out is good for you!

To get the best benefits for your heart and to burn a bit of body fat you should aim to exercise hard enough to get puffed out and stay that way for at least 20 minutes, and do that four times a week.

Then remember to also build activity into your day on a regular basis. Walk to the shops, cycle to work, get off the bus a couple of stops earlier. When you’re at work simple things like standing up to take a phone call and using stairs instead of lifts or escalators will all contribute to your well being.

But what about muscle? It’s hard to climb a few fights of stairs if your muscles aren’t up to the effort. Building strength helps us do our everyday activities without becoming exhausted or hurting our backs.

Our muscular system is complex and multi layered, with different types of muscles performing different functions. We may know the global muscles: the biceps and triceps in the arms, the gluteals in the buttocks, the quadriceps and hamstrings in the thighs.

The global muscles are the muscles of big movement, walking, picking things up, squatting down. These muscles operate two joints and are the outside ‘layer of the onion’ in muscle terms.

We need two types of ability in these muscles: muscular strength and muscular endurance. Strength is the ability to pick up a load and put it down again several times.

After a while your muscles will fatigue and you will need to stop. Muscular strength can be measured as 1 rep max, or the heaviest weight you can move just once. Think of a big bag of groceries, or a heavy child. A basic principle of strength training is to lift a load for just a few repetitions until the muscle fatigues.

With time and practise, as the muscle adapts to the weight, you are able to increase the load. This principle holds true for all forms of strength exercise including advanced Pilates which uses the body’s own weight to build strength. Improving our strength capability improves our quality of life: you can do more stuff if you are strong.

So what’s muscular endurance? Think of lifting up your heavy suitcase and then just holding it there. Keep it up! Our muscles need to be able to sustain their contraction for a period of time in order to hold our skeleton in place.

The global muscles perform an assisting role in this but the deep postural muscles are the primary muscles here.

From standing in a queue to running a marathon the muscles that stabilise the spine, pelvis and shoulder blades need good endurance qualities in order to do their job.

Are you ever slumped over your desk with a niggly back ache or get tired standing for quite short periods? You need better endurance in your postural muscles. Next time, I’ll talk about how to do it.

Patricia Issitt is a movement therapist and Pilates instructor. She opened York Pilates Space, a fully equipped Pilates studio in the city centre in 2004.