Running on the road uses your tensile strength whereas running on the beach uses your contractile strength.
TENSILE:
The tensile system essentially loads up the connective tissue and uses its elasticity to propel you forward – the key element here is the ground force beneath you that you are pushing off. The road is firm and fixed. The sand on the beach is not. Here’s an example of a gold medalist using his tensile system to great effect. He would not go so well on sand.
CONTRACTILE:
Your contractile system requires a lot more muscle activation to propel you forwards as you have far less ground forces to move forward. So you must make up for this by using more muscle activation to push you along and this is why the beach gives you more bang for your buck for the same amount of time.
- Active contractile force. If there is no external resistance, nervous stimulation causes the muscle to contract to its smallest possible length, which is about 60% of resting length. In this condition, the actin fibrils are completely curled around the myosin fibrils: in other words your muscles are working harder!
2. The tendon is a fibrous contractile tissue which connects muscle to bone, enables joint movement and maintains articular stability by transmitting the force created by muscle contraction to the bone. They therefore get stronger. As a result of working harder those muscles get stronger.
3. In fact, moving on sand uses up 1.6x more energy than on a hard surface. Reason being, the mechanical work getting your body to move in the unforgiving ground, and the inefficiency of the work done by tendons and muscles due to the sand’s unpredictable surface.
4. In fact, a 2013 study published in the Journal of Strength and Conditioning Research found that running on sand forces your body to work at least 10 percent harder than it does on grass, we can probably assume that number is even bigger when it comes to sand!
5. Running on grass or sand has many benefits for runners. The surface is soft and absorbent, which means less force is being placed on the knee with every step. Additionally, running in sand forces the activation of quadricep and hip muscles. These muscles support and strengthen muscles around your knees.
6. Training on soft sand has a wealth of benefits that are rarely known. For example, running on a hard surface at a speed of 10km/hr burns between 300 and 400 calories per 30 minutes of activity, depending on your weight. … Running on sand however burns 1.6 times the number of calories than running on a hard surface. So, aim for the same duration and you’ll burn a whole lot more calories doing so.
7. Running on sand makes running a little more difficult due to its softer nature. Alternatively, running on concrete provides a harder impact surface, making the running process a little easier as you don’t need to put as much force into pushing away from the ground with each stride. The ground forces though can be unkind to your joints if your technique is poor. Sand is far more accommodating!
8. You’ll strengthen your feet by running on sand more so that a hard surface. Feet tend to get weak when they are stuck in shoes all day. The brain loses connection with them and finds it hard to activate the appropriate muscles on command. Some beach time in or out of shoes will make your feet work harder they should therefore be a little bit smarter when you need them to be.
9. You will simply get stronger. As you are using more muscle fibres to propel you forward the muscles involved in the running motion will work harder and become stronger as a result. This will lead to happier hips, lower back and postural muscles that help you look young and healthy, especially if you sit at a desk most of the day!
10. We are all pushed for time, right?! So, running on sand gives you time back. You will get the workout on sand that you would get from a longer run-on concrete or tarmac. So when you are pushed for time – slip on the runners or go barefoot and you’ll get the same benefits in less time!
Check out the Fit 4 Life running package to help you improve where you are at and achieve those running goals.
Or alternatively lock yourself into an event that keeps you coming back for more like the Harcourts Copper & Co Beach Series.