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Feel the burn!

If you’ve been to a barre class, you know what I’m talking about. That burning sensation in your muscles, arms or legs on fire, uncontrollable shaking. That’s what’s called “The burn”. This is something you can experience during your workout, especially with barre.

It’s a challenging feeling that often triggers discomfort which turns your workout into a mental training. I get asked all the time about it after class. Many people think it comes from muscle weakness. But it doesn’t.

So let’s talk about ‘The burn’. What it is and the science behind it.

What is a barre workout?

First, a little background about barre. Further to a back injury, Lotte Berk, a German-born modern dancer, combined ballet barre routines with rehabilitative therapy to create a fitness system we know now as ‘Barre’. These workouts incorporate ballet, yoga, and Pilates-inspired elements and focus on low-impact, high intensity movements.

The results are serious: a sculpted lean and strong body.

A barre class is a full body workout. With small, targeted movements, isometric holds and pulsing techniques using light weight or resistance the muscles of each group are fatigued to the point they’re hitting overload. The aim is to get the muscles to their tightest point of contraction where the muscles max out. Muscle fibers start breaking down and enter a new repair process. That’s the point at which the fibers get to grow, strengthen, and lean out.

So, the burn or shake isn’t a bad thing at all! It’s simply a sign that the body’s becoming fatigued, that it gets out of its comfort zone. Which also makes barre a mental workout increasing resilience and stamina.

As with all workouts, Barre classes come in different tastes. I personally love including cardio blasts into my classes because they raise the energy and give endorphins’ high. Making it fun to feel that burn helps get through this challenging sensation and ensures we keep showing up class after class. That’s how in just a few weeks of regular classes results are there! Energy is boosted, you get fitter, your balance improves, and your body starts to tone.

Alright, now we’re about to get into more details and the science behind the famous burn. So, if you have no time or are bored by science, no worries, I got your back. Scroll down to the recap at the bottom of this post. Otherwise stick with me.

The science behind the burn

Understanding what’s happening to your body, can reassure you that such feelings (burning, shaking) are part of the process of getting fitter and stronger. So, here’s the science behind the burn.

There are two types of muscle fibers: slow-twitch (Type 1), fast-twitch (Type 2) which divide into two sub-categories. With barre we mostly workout our slow-twitch (Type 1) muscle fibers, building endurance and strength with pulsing techniques, high repetition of small, targeted movements.

Slow-Twitch vs Fast-Twitch Muscles

To function the body needs movement. Not only workouts. Respiration or eating are movements too, contraction of our skeletal muscles. These muscles are made up of the two types of fibers mentioned above. The difference between these is the way they create energy for their contractions. The more efficient Type 1 fibers are fatigue resistant and focused on sustained, smaller movements and postural control. Type 2 fibers fatigue quickly and are therefore better for short bursts of speed and strength.

Running a marathon or maintaining posture, for example, both require efficiency over time and mainly use slow-twitch muscle fibers. Highly vascularised they have many mitochondria. These are tiny cells producing energy using aerobic respiration (meaning with oxygen). Simply put, aerobic respiration is a process through which energy is created in the form of ATP from amino acids, carbohydrates and fatty acids. The energy provided by aerobic respiration is steady and large, it increases the oxygen capacity of the muscles so they can keep going for longer periods of time. Because of their low threshold, these fibers are activated before the fast-twitch muscle fibers.

Sprinting or heavy lifting, require short, powerful bursts of energy which are provided by fast-twitch muscle fibers. These are activated when the slow-twitch fibers have reached their threshold and can’t meet the level of energy needed. Their contraction is quick and strong because their energy is created by anaerobic respiration (without oxygen). Fast-twitch muscle fibers divide in two sub categories.

Type 2a is a sort of hybrid and uses both aerobic and anaerobic energy systems, they are less efficient and fatigue quicker than Type 1 fibers but produce more force. Type 2b produces the most force very quickly. They are highly inefficient due to their reliance on anaerobic metabolism. Fewer mitochondria are present in these fibers, ATP’s form quickly from glycogen, the stored energy inside the contracting muscle cells. This process is less efficient and builds up lactate and hydrogen ions.

Embrace the shake!

Let’s bring this all together now. Getting back to our barre class, at some point we all feel our arms on fire, uncontrollable shake in the legs. Been there?

Here’s why. The body creates energy through one of these three processes: phosphagen, glycolytic, and oxidative. Although these systems work together simultaneously, depending on the needs of the moment, one of them will predominate.

Fast-twitched (anaerobic) muscle fibers are activated during short term intensive exercise. They use energy stored into the muscles (Phosphocreatine or PC, is a high energy phosphate stored in the muscles) combined with glucose to form ATP. This is called the phosphagen system or ATP-PC energy system.

This system provides energy for high intensity efforts and is limited to about 10 seconds after which the glycolytic system is activated. This second system provides energy for only a few minutes and results in an accumulation of lacta