No Strength Gain Differences Found Between Low and High Load Exercise IF Reps Are Taken To Failure
In our previous blogs we have discussed the errors most exercise participants make when selecting intensity (amount of weight) while at the gym. Humans are often poor estimators and when it comes to strength training they often select weights below the intensity required to promote optimal strength and muscle gains. Trying to base a weight off a one repetitions maximum is time consuming, impractical, and possibly contraindicated for some weight training participants. Conversely, research articles continued to support using fatigue as an alternative to the 1 repetition maximum weight selections. Fatigue takes the guesstimation out of exercise weight selection and can be very effective at promoting optimal strength gains.
Dinyer and colleagues in The Journal Of Strength And Conditioning Research randomized untrained women to either a low or high intensity weight training program (2019). All of the women underwent clinical and body mass (% fat free mass) testing before and after the 12 week training program. Each group was assigned to a weight equaling a low (30% of 1 rep max) or high (80% of 1 rep max) intensity for 2-3 sets during 4 exercises (lat pulldown, military press, leg extension, and leg curl). Both groups took their workout sets to fatigue. Authors reported while both groups improved their maximum strength at the end of the 12 weeks there were no differences between the low or high intensity groups. In addition no changes in fat free mass were noted in the groups.
This study highlights the importance of working with a sub maximal weight and lifting it a maximum number of times for optimal strength gains. We recommend selecting a repetition range first (ex. 8-12 reps) then selecting a weight, but adjusting this weight higher if you can perform more repetitions than your established rep range.