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
A study into the physiological improvements of interval training vs traditional lower-intensity aerobic training compared “which factors responsible for oxygen delivery (total hemoglobin mass, blood volume, maximal cardiac output) would contribute to the expected improvements in cardiorespiratory fitness.” Essentially they found that “improvements in VO2max are mediated by both peripheral and central factors,” much as from aerobic exercise. MSSE June 2022
In a systematic review of studies for chronic low back pain (CLBP), it was found that aquatic exercise helped reduce pain and improve function, short term. A group of Chinese researchers investigated whether or not the benefits of a 3-month training regimen carried over for the next 3 months compared to a traditional PT program. Their results showed that pain was substantially reduced but functional improvements were no different between groups. Aquatics also ranked very favorably among those who completed the program vs those who completed PT. Physical Medicine & Rehab May 2022
A study by Dutch researchers tested the muscle protein benefits of potato protein ingestion compared to traditional milk protein ingestion. With greater interest in non-animal foods that are environmentally-sustainable, finding sources of high-quality protein for athletes is increasing. They had 24 healthy young males consume 30 g of each protein after doing the same one-leg resistance exercise routine on separate occasions. Blood and muscle biopsies were performed for 5 hours post-exercise to determine how well the different proteins were used by the muscles. Protein synthesis rates were nearly identical in the exercised legs; the synthesis rates were greater in the exercised leg than the rested leg. In conclusion, potato protein – NOT potato chips – is a viable source of post-workout supplementation. MSSE Sept. 2022