If you’ve ever seen Neil Hill train someone, you know that he slaughters his clients with his Y3T training system, but rest periods are fairly short, typically around 60 seconds. New research suggests that resting less between sets increases strength.
The researchers had resistance-trained men perform a 12-week study, the control group performed a traditional resistance-training program with four sets and 120-second rest periods whereas the other group performed eights sets of five with 60-second rest periods. Before and after the 12-week program and at weeks 4 and 8 the researchers measured body composition, took muscle biopsies, and measured strength and power output.
At the end of the 12-week program, the 60-second rest-period program produced greater gains in bench press and squat strength. There were equal changes in muscle mass between the two groups. This means you can get in and out of the gym faster with more impressive gains in strength by resting less between sets.
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THE CARDIO CONUNDRUM
There has been much debate on how aerobic exercise can impact muscle mass. Studies have found that resistance exercise and aerobic exercise elicit different gene responses in muscle.
Researchers wanted to explore the effects of different types of exercise on the AMPK and mTORC1 signaling pathways in human skeletal muscle. AMPK increases cellular energy levels by inhibiting anabolic pathways and stimulating catabolic pathways. On the other hand, mTOR stimulates anabolic pathways, including insulin, growth factors (such as IGF-1), and amino acids. The researchers divided the subjects into three groups: a strength-training group, an endurance-training group, and a control group.
The endurance-training group performed 10 weeks of stationary cycling composed of three sessions per week with Session 1 involving 30–45 minutes at 60–75% of maximum power output. Session 2 involved two intervals of 20 minutes at 70—80% of maximum power output with five minutes of light cycling in between, and Session 3 involved eight four-minute intervals at 80—90% of maximum power output. The resistance training group carried out a conventional progressive overload training program, comprising three leg exercises performed for 3–5 sets of 4–6 reps to failure with two to three minutes’ rest between sets.
The researchers reported that AMPK (i.e., catabolic pathway) increased by 44% in response to endurance training and 10% in response to strength training. The mTOR pathway increased by 91% in the resistancetraining protocol along with several other anabolic pathways. So both aerobic exercise and strength training led to the activation of the catabolic pathway AMPK, but resistance exercise was the only exercise component that led to the exclusive activation of anabolic pathways. So doing cardio by itself can lead to a greater activation of catabolic pathways, but this study doesn’t address the question of whether combing cardio and strength training inhibits muscle growth, which leads to the next study.
Researchers had subjects perform two trials, one involving only resistance training and the other involving both resistance and endurance training. At the end of the study, resistance exercise seemed to provide a protective effect, mTOR increased in both trials, and that there was no significant difference between trials. So the good news is that when endurance exercise is performed directly after resistance exercise, the mTOR anabolic pathway is not blunted. – FLEX
