When the goal is increasing maximal strength, one of the best things to add to your training is to incorporate strength devices like chains, bands, and bungees, that alter the resistance curve. Each device works a little differently, but they all share a few basic principles.
- The goal of the device is to increase resistance where the leverage is best. This is the top of a squat, dead lift, or pressing movement for example.
- They are best used on exercises with a ballistic concentric portion of the repetition. Two examples would be explosive squats and bench press. The concentric portion of the exercise should be performed as explosively as possible. Failure to do so will result in fewer gains, and slow repetitions allow fatigue to limit intensity of the exercise.
- They are best used with lower repetition sets. The fist reason you should only use these devices with low repetitions (1-3) is using these strength devices increases concentric time under tension. Secondly, since the goal is to maximize recruitment throughout the range of motion, the muscles will fatigue faster and maximum weights are required to achieve the goal of the device. Using a weight where you can perform more than 5 reps would not recruit enough motor units to be more beneficial then simply using a heavier weight with no strength device.
- The optimal bar weight to use when training with a device is 40-50% 1RM for most. However, this may not be possible for stronger athletes if equipment is limited. For maximal safety, staying under 30% of weight on the device is best.
Chains are the most commonly used strength device. They provide a linear increase in resistance as the chain is lifted off the floor, applying additional weight to the bar. For large movements like squats, additional chains can be hooked on to provide extra weight at certain portions of the rep. For example an additional chain could be set to just come off the ground just as a knees pass 90 degrees on the way up. When setting up chains on the bar, the length should be set so that a portion of the chain never leaves the ground. This prevents excessive swinging of the chains which would decrease the stability of the movement.
Bands differ from chains in that the increase in resistance is progressive. In other words the more the band stretches, it increases resistance faster and faster, almost exponentially. So the difference in resistance at the beginning and end range with bands will be greater than chains. Bands also provide more decelerating resistance on the way up and increase acceleration during the eccentric portion of the exercise. Because of this, control over the eccentric movement should be considered for safety. One major issue with bands is quality control. It’s much harder to find bands that are equal in resistance. The difference in some brands can be quite considerable which would lead to unilateral strength discrepancies and altered recruitment. Bands also have a tendency to produce more acceleration force during the eccentric portion of the rep. In other words they will pull the weight down harder and faster than gravity, creating a crushing feeling. This can create excess stress during squats and deadliest. Bands because of their safety issues should be used by more advanced trainees with proper coaching.
The mechanics of the bungee are identical to the band. The main advantage of bungees is versatility. Bungee systems usually allow for easy change of resistance and more ergonomic setup. They still however share the same issue of matching resistance between bungees and more acceleration of force.
How NOT to use bands and chains.
Don’t use exercises that don’t match the resistance curve. Exercises like curls or chin-ups where the leverage isweaker at the end position will not benefit from using bands or chains. Making the exercise more difficult in the weak position will just force a lighter weight during the rest of the range of motion, resulting in an inferior exercise. An exercise recently made popular by some fitness DVDs is the assisted pull-up using heavy bands for individuals who can not perform a bodyweight pull-up. If you are doing these in a group class for the simple goal of fat loss, it not too bad. However, a better way to master the pull-up can be found here
Do not perform high reps with strength device. For your higher rep training, you are better suited when your goal is not strength. If you are going to perform 6 or more repetitions you are better of utilizing different exercises in a superset to recruit additional fibers. If you are going to train for strength, train strength. Don’t train another goal using a strength or speed device.