The purpose of this study was to determine whether a relationship exists between 1-repetition maximum (1RM) performed on hammer strength (HS) machines compared to free weights (FWs) and also to develop regression equations that can accurately predict 1RM when switching from exercise modality to another. Thirty-one trained male subjects performed 1-RM lifts (1RM's) on 3 HS externally loaded machines and 3 comparable FW exercises. Subjects performed 2 1RM tests during each laboratory session, with at least 48-72 hours of recovery between each. One repetition maximum data were used to (a) determine the relationship between 1RM performed on HS vs. FW and (b) to develop regression equations that can accurately predict 1RM's when switching from 1 exercise modality to another. Statistics revealed significant differences (p < 0.05) between 1RM's performed on the HS equipment as compared to its corresponding (FW) exercise. For all exercises, 1RM's were significantly greater on the HS equipment. Regression equations were developed for all exercises, except when predicting the HS shoulder press and the HS preacher curls from their free weight counterparts, where no variables existed that could significantly predict their respective 1RM's. As 1 RMs were significantly greater when using the HS equipment compared to when using FWs, those transitioning from HS exercise to FW exercise should exercise caution.
The exercises/machines are bench press, overhead/shoulder press and bicep/preacher curl?
Wouldn't it be easier to calculate the mechanical advantage offered by each machine vis-a-vis the weight loaded on the machine at x hand positions (given that HS machines offer various hand positions) and distances from the fulcrum. As an example, you know that a 45 degree leg press provides a 50% mechanical advantage vs. a vertical leg press, and on cables it's more or less the weight divided by the number of pulleys...
I'd be more interested in knowing about their rowing machines, since that is all I really use. I prefer having the trunk supported during pulling exercises...
Canuck eh wrote:I'd be more interested in knowing about their rowing machines, since that is all I really use. I prefer having the trunk supported during pulling exercises...
I share the same preference. Wouldn't be an apples to apples comparison since most people use a lot of body english when barbell rowing near their 1RM.
Now a chest supported barbell row, that would be more valid. Personally I have a hunch that the row would show less of a difference between free weights and machines. The bar's path is more or less straight and more stable either way.
