Written by Marissa Hoen | August 25th 2020
Have your muscles ever started to shake during the last few reps of your squats or bench presses? Have you felt your abdominals wobble during your core exercises?
Why do our muscles shake during exercise?
During a workout at MOVE I was asked why our muscles shake during exercise and if this shaking is safe. My mind immediately thought of fatigue- which can occur both in the muscle and in the neural connection to that muscle. While there are a few reasons for the shake, muscle shaking during exercise is most commonly a symptom of fatigue.1
Will I get stronger if I reach the shaking point in my workouts?
In her blogpost on exercise-induced muscle shaking, Meredith Melnick said it best: “while working yourself to the point of exhaustion will help improve your fitness, working through that exhaustion will not.”2 Training to the point that you begin shaking is one way to measure the intensity of your training. Training beyond this point can lead to injury if fatigue is impacting the biomechanics or form of your exercise, or if the shaking leads to a fall. If you have support and higher intensity exercise is safe for you, then go for it! It is totally fine to shake a little bit, just be mindful and learn your limits. Reducing fatigue symptoms can help to postpone the shaking, helping you get more out of your workout.
Ways to reduce fatigue for longer workouts:
Eat that carb! Before your workout sessions, make sure you have eaten some healthy carbohydrates (such as your favorite fruit or some oatmeal) so your muscles have enough energy to achieve your movement goals. Inadequate carbohydrate stored in muscle is a major contributor to muscle fatigue.1
Hydrate! Make sure you’re getting in enough water- whether it be through water dense foods (fruits and vegetables) or actual water. Without water, many cellular processes slow down and the body heats up- avoid dehydration by carrying a water bottle with you.
Workout with others. Exercising with other people seems to be more effective than exercising alone in terms of improving fitness and psychological well being.3 Having people around you can motivate you to push a little more, or remind you to breathe!
Remember to breathe and take breaks when needed. Hypoxia, or lack of oxygen, causes fatigue both in our central nervous system and in our muscles. Amann et al. found that breathing more intensely during exercise causes fatigue in the breathing muscles themselves, which in turn leads to more fatigue!4
References
1Knicker, A., Renshaw, I., Oldham, A. et al. Interactive processes link the multiple symptoms of fatigue in sport competition. Sports Med 41, 307–328 (2011). https://doi-org.ezproxy.library.uvic.ca/10.2165/11586070-000000000-00000
2Melnick, M. (2012). Muscle shaking: Is your workout better if your body trembles? Retrieved from: https://www.huffingtonpost.ca/entry/muscle-shaking-causes_n_2140397
3Dickman, N., & Boutcher, S. (2005). Effect of exercise and the exercise setting, group vs alone, on the psychological wellbeing and fitness of older women. Journal of Science and Medicine in Sport, (8)1, pg 89.
4Amann, M., Pegelow, D., Jacques, A., & Dempsey, J. (2007). Inspiratory muscle work in acute hypoxia influences locomotor muscle fatigue and exercise performance in healthy humans. AJP Regulatory Integrative and Comparitive Physiology, Environmental. Doi: 10.1152/ajpregu.00442.2007
Image Credit: https://www.vectorstock.com/royalty-free-vectors/chair-exercise-cartoon-vectors