High and Low responders' energy intake, protein intake, sleep, etc., were identical. Hard gainers made equal strength gains to hyper responders based on their body weight. Hard gainers did not have differences in protein synthesis or ribosome content compared to hyper responders. Protein synthesis was not associated with gains in muscle mass. Hyper responders had a greater satellite cell response than low responders.
SUMMARY OF HARD GAINERS VS. HYPER MUSCLE RESPONDERS
- Hard gainers did not have differences in protein synthesis or ribosome content compared to hyper responders.
- High and Low responders’ energy intake, protein intake, sleep, etc., were identical.
- Hard gainers made equal strength gains to hyper responders based on their body weight.
- Protein synthesis was not associated with gains in muscle mass.
- Hyper responders had a greater satellite cell response than low responders.
HOW DO MUSCLES GROW?
Some people can’t grow muscle as fast as they want while weight training. Scientists may have an answer if you are one of the many people who are seeing no results working out and not gaining muscle mass. So how do you know if your muscles are growing while lifting weights?
An easy way to track muscle growth and fat loss is using tape circumference measurements to track increases in muscle size regularly. If your clothes fit a little tighter, that’s a good sign you are adding muscle and hopefully minimal fat.
Before going into the study, a few mechanisms have been suggested to influence muscle tissue growth. Researchers have suggested higher responders gain more muscle because of a greater increase in muscle cell ribosome content increases, satellite cell activation, and increased protein synthesis. (Mobley et al., 2018; Roberts et al., 2018)
HARD GAINERS: WHY ISN’T MY WORKOUT WORKING?
Hyper-responders or extreme muscle responders grow muscle easily in response to weight lifting. They are genetically blessed to gain muscle faster than most people.
Contrary to hyper-responders, there are those classified as low responders or a true hard gainer. Low responders can’t seem to gain muscle fast despite doing the same workout as a high responder. (Davidsen et al., 2011) The typical low responder has the body type of an ectomorph (i.e., skinny).
One study found high responders experienced a 30% increase in muscle growth, whereas low responders gained no muscle or a small ~4% increase in muscle size. The hyper-responders gained more muscle despite using the same routine. (Franchi et al., 2018)
A study of 585 subjects who followed the same training program looked at the differences in muscle growth responses: 232 subjects gained increases in muscle size between 15-25%, 10 subjects gained 40%, and 36 subjects gained less than 5%. (Chung et al., 2021)
Hyper-responders gain muscle fast, but they also lose it faster! After quitting exercise, high responders lost 10.5% of their muscle mass, whereas low responders only lost .6% of their muscle mass. (Räntilä et al., 2021)
A NEW STUDY LOOKED AT MUSCLE GROWTH BETWEEN HARD GAINERS AND MUSCLE RESPONDERS
Researchers took people from a study and analyzed those that were hyper muscle responders vs. slow responders. The resistance training protocol was a 10-week progressive overload program. This study looked at everything!!! They examined protein synthesis, gene responses (i.e., ribosome content), satellite cells, etc.
They wanted to know what exactly made the hyper-responders different from those who couldn’t gain muscle. The high and low responders were those in the top and bottom 25% for muscle gains. (Smith et al., 2023)
GYM MYTH #1: HARD GAINERS DON’T TRAIN HARD:
The researchers found that the hyper-responders had more muscle at baseline or right when they entered the study. The high responders trained with a heavier weight throughout the study, but this was because they weighed more. The hyper responders had greater pre and post-bench press, leg press, and deadlift strength metrics.
However, when the researchers equalized the weights used while training based on body weight, there were no differences between the high and low responders. The low responders made comparable strength gains based on their body weight. So low responders are not gaining muscle because they don’t train hard enough. They had equal strength increases based on their relative body weight.