Strength Training: To Failure or Not to Failure?
A group of Brazilian researchers aimed to answer one of the burning questions in exercise science: for older adults using low-load resistance training (LLRT), do you have to achieve muscle failure or can you stop before failure? Muscle failure is potentially painful and even injurious for older and younger lifters, so this study might give comfort to participants, and their trainers. While specifically concerned with RT volume, we have discussed strength training issues for post-menopausal women here, here, and here.
Dividing 41 subjects (60-77 y/o) into three groups – Failure (F), volitional cessation (VC), and fixed-repetitions (FR) – each group lifted 2/wk for 12 weeks at 40% of their 1-rep max (1RM.) Ideally, for strength improvements, you lift at 60-95% of your 1RM. So this was clearly a LLRT program. All were tested on their 1RM improvement, hypertrophy/muscle growth, rate of torque development (RTD), and 4 functional tests (chair stand (CS), gait speed (GS), max walking speed (maxGS), and timed up-and-go (TUG.)
All groups improved their 1RM on knee extension (quadriceps), knee flexion (hamstrings), and leg press to similarly moderate extents. This despite the fact that F had lifted more total reps than VC or FR! Not only that, the F group had a smaller improvement in RTD than the others – excess residual fatigue? Who knows?
The VC group actually had greater relative improvements on the 2 functional tests where improvements were noted – CS and GS. The FR did not benefit nearly as much in these tests. In the maxGS and TUG, insignificant gains were made in all groups with no statistically significant improvements in either group.
The authors conclude that LLRT in older adults “promotes significant improvements in muscle strength and…functional performance.”
JSCR May 2022
Training Volume Ups Size, Not Strength, in Older Women
Many studies have compared 1 set of a variety of strength exercises to 3 sets, or sometimes even 4. Most of these failed to demonstrate that 3>1 when it came to increasing lean muscle mass (LMM) in older women, a worthy goal metabolically (LMM burns more calories) and functionally (LMM enhances movement and fall prevention.) Also, 3 sets do improve muscle strength (MS) compared to 1 but not nearly as much in older women as in younger ones.
This study from Brazil, then, pushed the envelope with a 3/wk x 12-wk resistance training program: 3 sets (LV: lower volume) of lower body exercises vs 6 sets (HV: higher volume.) The exercises included leg press at 45 degrees, knee extension (quadriceps), knee flexion (hamstrings), and heel raises (calf muscles) at 80% of each exercise’s 1 rep max.
At the end of the study, both groups increased LMM and MS compared to the controls. The HV increased LMM by nearly 3 times what the LV group did: ~0.8 kg vs 0.3 kg, respectively. This amounted to about 1.7 lbs vs 0.7 lbs, so, no neither increased leg girth to any extent worth worrying about.
While there was no statistically signficant difference in MS gains between the two exercise groups, there was a trend toward greater increases in MS in the HV group.
In conclusion, it takes a lot more stimulus to increase muscle size in older women than previous studies have shown but 3 sets will get you enough benefits in LMM and MS…without making your legs bigger!
JSCR May 2022