Leg days in the gym are tough but equally rewarding. Strong legs provide the foundation for a healthy and active life. They also help to handle the load of the body better and maintain good posture. The legs also help to prevent injuries to the lower back, hips and spinal cord. While squats and its various iterations provide a wholesome workout to the lower limbs, leg extension and leg curls are must-do exercises as well since they isolate and work the muscles in the region.
Leg extension works the quadriceps muscles (rectus femoris, vastus intermedius, vastus lateralis and vastus medialis) of the thigh region while leg curls work the hamstrings (biceps femoris, semimembranosus, semitendinosus) on the back side of the legs. These muscles play an important role in various functions like walking, running, jumping and flexing (bending) of the knee. Using the leg extension and leg curl machines are also prescribed for injury rehabilitation.
Leg curls and leg extension: common mistakes
While the two machines are great, they are not meant to lift heavy loads. This is a common mistake that many commit. Experts point out that the machines are meant for toning and not building muscle mass. So, heavy weights should be avoided. Besides, lifting heavy weights while performing leg extension or curls can lead to knee injuries.
“About 80% of the people commit the common mistake of lifting heavy weights with leg extension and leg curl machines,” says Nagesh Rao, master fitness trainer at Rockwall Fitness in Bengaluru, India. “The main function of the two machines is to provide toning to the muscles, so there is no need to lift heavy weights. Many a times, the trainee confuses the purpose with other exercises, or they are not properly briefed by their trainers. The ideal exercise for the two machines should be a low intensity one with less weight and more repetitions with a maximum of three to four sets for each.”
Warm-up, preconditioning and stretching should be performed before doing these exercises to avoid injuries or muscle catches.
Knees are vulnerable to injury
Knee joints are the only joints that work while performing leg extension and leg curls.
The knee joints can bear loads but only to a certain extent. If these exercises are done recklessly without an expert’s supervision, then it could adversely affect the knees. The injuries range from minor knee pain to ligament tears and synovial fluid leak among others. Over time, it could also lead to walking difficulties.
Strengthening muscles through body-weight exercises
“Before starting exercise on these two machines, it is important for an individual to first master body-weight exercises like lunges and squats,” says Rao.
Lunges and squats should be done initially without weights and once the appropriate motion is mastered, weights can be added. Only then should one progress to leg extension and leg curl machines.
Takeaways
- The leg extension and leg curl machines tone the quadriceps and hamstrings muscles.
- Since knees are the only joints which flex during the exercises, they are vulnerable to injuries.
- One should avoid heavy weights while doing leg extension and leg curls. Before using the machines, it is important that the quadriceps and hamstring muscles are strengthened through body-weight exercises like squats and lunges.
