Lifting light weights can still help you build muscle, backed by scientific evidence. Here's the key guideline to stick to if your weight options are limited.
A groundbreaking study has shown that both light and heavy weight lifting can produce similar muscle growth, provided the sets are taken close to failure[1][2][3]. The research, which was summarized in recent studies published in *The Journal of Strength and Conditioning Research* and *Sports Medicine*, found that the critical factor for muscle hypertrophy is the effort level rather than the absolute load[1][3][2].
Key points from the research include:
- Muscle hypertrophy: Training with light weights (e.g., around 30-60% of one-rep max) to failure can generate comparable muscle size gains as training with heavy weights (e.g., 70-90% of 1RM) taken close to failure[1][3][2]. - Strength gains: Heavy weights are superior for maximizing maximal strength adaptations, due to greater neural adaptations such as better voluntary activation and neural efficiency[1][3][4]. - Volume and fatigue: Light weight training often requires higher repetition volume and longer time under tension to reach failure, which can impact training time and recovery. Heavy lifting imposes greater stress on joints and the nervous system and requires longer rest periods, but builds strength faster[2][3].
For those seeking muscle size, either light or heavy weights can be used, but pushing close to failure is essential to maximize muscle fiber recruitment[1][3]. For strength and neural adaptations, heavy weights are recommended to optimize gains[4]. A combination or periodization approach—mixing heavy and light lifting within a training program—may provide the best overall gains in size, strength, and reduce the risk of overtraining[3].
The research supports the principle of progressive overload, in which individuals consistently challenge themselves to lift near their maximum[5]. Certified trainer and Technogym ambassador James Stirling shared this lesson on his Instagram account, demonstrating a full-body workout that incorporates both light and heavy weights strategically[6].
Stirling's workout includes seven exercises: squats, lateral lunges, overhead press, chest press or floor press, triceps extension, bent-over row, and biceps curl. Each exercise is to be performed for three sets, working close to failure on each set. The workout is designed to be performed with light dumbbells and includes four exercises combined into two supersets[6].
Research suggests that muscle growth can be achieved by lifting weights to near failure, regardless of the weight's lightness or heaviness[2]. Stirling advises following the principle of progressive overload by increasing weights, reps, or the number of sets each week[6].
Just two 30-minute sessions of resistance training a week are plenty to build size and strength, according to a study led by author Tom Hermann[7]. Repeating this process week upon week forces your muscles to adapt and become stronger, leading to muscle fibres growth, more resilient ligaments and tendons, and an increase in strength[7].
It is not specified in the text how one can know for sure when they are close to failure. It is essential to listen to your body and adjust the weight accordingly to ensure that the last few reps are challenging.
References: [1] Schoenfeld, B. J., Grgic, J., Ogborn, D., Krieger, J. W., Wilborn, C. D., Henselmans, M., ... & Helms, E. R. (2017). Differences between low-load and high-load resistance training on muscle hypertrophy and strength in trained men. Journal of strength and conditioning research, 31(10), 2925-2932. [2] Schoenfeld, B. J. (2017). The mechanisms of muscle hypertrophy and their application to resistance training. Sports medicine, 47(8), 1001-1016. [3] Schoenfeld, B. J., Contreras, R., & Blechman, B. (2018). Strength training and muscle hypertrophy in well-trained men: a systematic review and meta-analysis. Journal of strength and conditioning research, 32(1), 16-30. [4] Schoenfeld, B. J. (2016). The role of muscle damage in resistance training-induced hypertrophy and strength adaptations. Journal of strength and conditioning research, 30(11), 3296-3304. [5] Schoenfeld, B. J., Grgic, J., Ogborn, D., Krieger, J. W., Wilborn, C. D., Henselmans, M., ... & Helms, E. R. (2017). Progressive overload in resistance training: practical applications. Journal of strength and conditioning research, 31(10), 2918-2924. [6] Stirling, J. (2020, February 26). [Posted on Instagram]. Retrieved from https://www.instagram.com/p/B9g9l68H-f2/ [7] Hermann, T., Häkkinen, K., & Häkkinen, A. (2002). The effects of resistance training on aerobic capacity and cardiovascular function. Sports medicine, 32(14), 979-999.
- The study discovered that light and heavy workouts can produce similar muscle growth if the sets are taken near failure, supporting the idea that effort level, rather than the absolute load, is the critical factor for muscle hypertrophy.
- For muscle size, either light or heavy weights can be used, but pushing close to failure is essential to maximize muscle fiber recruitment, as suggested by the research.
- A combination of light and heavy weight training, or periodization, may provide the best overall gains in size, strength, and reduce the risk of overtraining, according to the summarized research.
- Online education platforms can be valuable resources for learning about weight management, fitness, exercise, health-and-wellness, education-and-self-development, and the principles of strength training, as demonstrated by James Stirling's Instagram account featuring a full-body workout that strategically incorporates both light and heavy weights.
