Does exercise actually increase your energy?
Fitness and regular exercise have been linked with good health and longevity. Healthy lifestyle has become an ideology defined by a very vague set of principles:
- Move/train more
- Eat less
- Eat natural/organic food
- Sleep more
- Drink more
- Meditate
If a person gets asked whether their lifestyle is healthy or not – they would judge themselves based on the standards I just mentioned.
What does drink more exactly mean though? Sleeping more – what exactly is more? Eat less – less than what?
Today I want to explore something that’s been repeated a ridiculous amount of times. Exercise increases your energy. The reason I want to write about this is based on a question I was asked last week. This person said they felt more tired after doing some cardio than beforehand. So what’s the story there? Does exercise actually increase your energy?
What is exercise/physical activity?
Exercise involves physical activity, exerting movement and increasing the heart rate. Physical activity requires energy to fuel the increased demand. When a car is parked, the engine is switched off and it doesn’t use up any fuel. Our bodies, which are often being compared to cars (resemblance being uncanny, right?), don’t operate the same way combustion engines do. Regardless whether we train, or not, our bodies require a certain amount of energy to keep going. The sum of all these process is called your Basic Metabolic Rate. What it means – even when you don’t exercise, you still need energy to live!
Let’s say you decide to do a 30 min jog. This form of physical activity requires fuel in the form of calories. You tap into your energy stores, the heart rate goes up, the body kicks into a higher gear to facilitate your jog – you get tired. Even more so, when you are not used to this type of activity. Exercise makes you tired!
There is nothing wrong with being tired after exercise, in fact it’s natural. You say you feel great after exercise? More “energized”? More awake? Brilliant. Your body has most likely released a decent amount of endorphins which trigger the sensations you’re experiencing.
To sum it up – exercise can make you tired, immediately after or during your workout.
The article doesn’t end here though. When you exercise a number of processes take place within each, individual cell. It is at the cellular level that we “generate” energy to fuel our performance.
During exercise the contracting muscles generate force or power and heat. So physical exercise is in fact a form of mechanical energy. This generated energy will deplete the energy stocks within the body. (1)
It is expected that at some point during/after exercise you are going to hit the wall and get tired. It is a protective mechanism to stop you from hurting yourself. You can work and improve this tolerance by regular training with applying the principles of progressive overload. What is also important to note is the role of recovery in periodized programmes.
Research by Puetz TW, O'Connor PJ, Dishman RK (2) showed that exercise did indeed improve the energy levels and reduced fatigue.
One would think that the increased energy levels are the result of improved aerobic capacity. Truth be told, the research does not find that improved aerobic capacity acts on the energy levels. It is more likely that the exercise impacts directly on the central nervous system.
The research had it’s limitations. Majority of people who start exercising, tend to improve other aspects of their lifestyle as well, ie. Sleep, nutrition. It is very hard to tell the impact of exercise alone. It is also important to note that the energy/fatigue levels are self reported and it often comes down to the perception of the individuals.
Therefore exercise, in the long run, can improve your perceived energy levels and reduce the sensation of fatigue. Why? It’s not certain just yet. More research needs to be conducted in this field.
To sum it up, exercise has many health benefits. It can decrease your energy levels during/post training but only to potentially improve them in the long run.
1. Ament W, Verkerke GJ. Exercise and fatigue. Sports Med. 2009;39(5):389-422. doi:10.2165/00007256-200939050-00005
2. Puetz TW, O'Connor PJ, Dishman RK. Effects of chronic exercise on feelings of energy and fatigue: a quantitative synthesis. Psychol Bull. 2006;132(6):866-876. doi:10.1037/0033-2909.132.6.866