TedEd: What makes muscles grow?

A TedEd by Jeffrey Siegel

There are over 600 muscles in our body that hold us together and allow us to move. Most people know that the way you treat them on a daily basis determines whether they grow or shrink. Muscles work by receiving electrical signals from the brain via neurons, which causes them to contract or loosen. If a task is harder, the brian puts more muscles to use. With most everyday tasks, your muscles experience easy loads. But when it encounters a difficult task, the muscles strain, causing microscopic damage. This might sound bad, but it's actually how muscles grow. Your immune system deploys cytokines to the damaged area to rebuild the muscle, causing that muscle to grow. When your muscles are not exposed to consistent strain, they shrink in a process called muscular atrophy. Putting your muscles in high tension, especially when they are lengthened (eccentric contraction) causes them to grow. In addition to exercise, muscles need rest and nutrition to grow. They need proteins you consume with your food, as well as hormones like testosterone that encourage growth. There are also genetic factors because some people have a more robust immune system to facilitate muscle growth.

Time: The G7 Wants to Save the World from Climate Change. But Are They Willing to Pay for It?

By Ciara Nugent

    As countries look to recover from COVID-19, and with leadership that cares about climate change in major countries, the G7 summit in Cornwall this weekend finally seems set for success. In May, the 7 countries in attendance agreed to end financing of overseas coal projects. Additionally, many are recognizing the geopolitical advantage of staving off climate change. Doing so could give them more power and create allies in developing countries. It also means that other countries, like China, may be more willing to cooperate.

    The summit is key because many countries are currently creating bills geared toward pandemic recovery. The policies created at the G7 could have an impact on the use of fossil fuels, and more importantly, how much wealthy countries will help smaller ones. Small, developing countries need the most energy, and the cheapest way to get that is fossil fuels. Because they have less money, this is the only choice unless larger countries offer financial aid for eco-friendly alternatives. Since larger countries are spending lots of money on their own recovery, help would likely come through corporate investments and subsidies.

    If fossil fuels are not ended, the changing climate will bring more and more natural disasters, as the US has already seen with hurricanes. Several countries are concerned that transitioning to renewable energy will cause shortages, but "IEA director Fatih Birol responded that countries were 'missing the point' on security. Though transitions to clean energy 'won’t succeed if they undermine the supplies of energy that billions of people rely on,' he wrote, 'A world ravaged by climate change from fossil fuel emissions won’t be secure.'"