Our ancestors carried things for hours every day as they walked. When we carry things our muscles engage in isometric contractions. So, when we walk with a picnic, the muscles in our arms, shoulders and core contract and stay contracted until we put it down. This builds strength without impacting our joints, because they don’t move.
There are three types of muscle contraction: concentric, which is when we lift a weight and they shorten; eccentric, which is when we lower a weight and they shorten; and isometric, which is when we hold a muscle for a long period. They work together, stabilising and supporting our limbs, but isometric contraction is good for strength, mobility and endurance. Nowadays we use it very little, despite it using 95% of muscle, compared to 88-90% used during concentric and eccentric muscle use. Isometric exercises are often used in rehabilitation programmes, yoga, climbing, cross-country skiing and ballet, or holding babies and small children.
Walking and carrying is also known as ‘loading’ or ‘loaded carry’, and is much more complex than lifting a dumbbell. Our brain has to work out how to maintain our balance when we walk carrying something heavy. People used to carry enormous armfuls of garden produce to sell at the local market. Our arms are not designed to lift up and put down heavy objects, but rather to carry them for long periods. Our muscles atrophy when we don’t use them in this way.
Here are some tips for walking with a picnic:
- Make sure your weight is evenly distributed, possibly using a ‘farmer’s walk’ or a ‘suitcase carry’ (carrying something in each hand). Or use a ‘bear-hug’ or ‘sandbag’ carry, where you hold the weight close to your waist with both arms.
- Bend from the legs when you pick something up.
- Change direction from your feet, not from your waist.
- Keep your spine straight and engage your core to protect your back.
- If you use one arm to carry the load, your brain will tell your other arm to stay strong.
- Put some of the picnic on your back, especially on a long walk.
Source: 52 Ways to Walk: Annabel Streets – Bloomsbury Publishing