The Claim
A 12-week high-intensity, low-volume concurrent resistance and interval training program increases maximal strength and lean body mass in recreationally active men and women, but does not improve aerobic capacity.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
After 12 weeks of a specific high-intensity training program that combines strength and interval exercises, recreationally active men and women gain muscle strength and lean body mass, but their aerobic endurance does not improve.
See the scientific wording
A 12-week high-intensity, low-volume concurrent resistance and interval training program increases maximal strength and lean body mass in recreationally active men and women, but does not improve aerobic capacity, suggesting that this training protocol effectively builds muscular power and mass without enhancing cardiovascular endurance.
Heavy lifting and short bursts of intense exercise pull on muscle fibers, triggering signals that build bigger muscle fibers and shift muscle type toward more efficient forms. This increases strength and muscle mass. At the same time, the body makes more enzymes to process energy inside muscle cells, but it does not build more structures needed to use oxygen during prolonged activity, so endurance does not improve.
What the research says
1 studyThis study found that doing heavy lifting and short, intense workouts three times a week for 12 weeks made people stronger and added muscle, but didn’t help them run or cycle better. So yes, it works as described.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.