Strength training: An effective tool for managing LDL cholesterol, insulin resistance, and fatty liver

Strength training is a form of exercise aimed at maintaining and increasing muscle strength and muscle mass through various resistance training exercises. Traditionally, strength training has been viewed solely as a means to improve muscular fitness, but recent studies have shown that it offers much more: strength training has favorable effects on many key health indicators, such as blood lipid levels, insulin sensitivity, and liver health.  

In this article, we will delve into the research evidence and examine how strength training affects LDL cholesterol, insulin resistance, fatty liver, and even liver fibrosis.

Several randomized controlled trials and meta-analyses indicate that strength training can significantly lower LDL cholesterol levels. A comprehensive review published in 2019 (Costa et al.) showed that regular strength training moderately reduced LDL cholesterol compared to control groups. Typical exercise programs included full-body workouts performed 2-3 times a week, lasting 8-24 weeks, and conducted at moderate or high intensity.

Interestingly, effects have been observed in both healthy adults and individuals with pre-existing elevated lipid levels. For example, in a study where premenopausal women engaged in fairly high-intensity strength training (with nearly maximal loads) for 14 weeks, LDL cholesterol levels decreased by 14%. This demonstrates that clinically significant improvements can be achieved even with a relatively short and intensive program. 

Strength training is therefore a recommended lifestyle treatment, especially for individuals with dyslipidemia or risk factors for cardiovascular diseases.

Insulin resistance is a key risk factor for metabolic syndrome and type 2 diabetes. Insulin resistance is also associated with high cholesterol. Insulin resistance and high cholesterol are related because insulin affects fat metabolism. When cells do not respond properly to insulin (i.e., insulin resistance develops), the liver begins to produce more triglycerides and VLDL particles (a type of "precursor" to LDL cholesterol).At the same time, HDL ("good cholesterol") often decreases and LDL particles become smaller and denser – which increases the risk of cardiovascular disease.

Insulin resistance thus disrupts the normal transport and storage of fats, which raises blood cholesterol and fat levels.

 Research shows that strength training can significantly improve insulin sensitivity. 

In several randomized studies, such as those by Zou et al. and Son & Park, it was found that regular strength training reduced the HOMA-IR value, which measures insulin resistance, and improved glucose metabolism. Training improved not only insulin sensitivity but also lowered fasting insulin levels and enhanced results from glucose tolerance tests.

Meta-analyses confirm that particularly moderate to high-intensity strength training, performed 2–3 times a week for at least 8–12 weeks, improves insulin sensitivity. Therefore, strength training is especially important for at-risk groups, such as those who are overweight, have metabolic syndrome, or struggle with high cholesterol.

Fatty liver is a condition in which excess fat accumulates in the liver without significant alcohol consumption. Fatty liver is strongly associated with overweight, abdominal obesity, insulin resistance, and high blood lipid levels. Since there is currently no medication available, lifestyle changes are the primary form of treatment.

 Extensive research evidence shows that strength training can significantly reduce liver fat content, even without significant weight loss. For example, Hallsworth et al. and Peng et al. reported that 8–12 week strength training programs reduced liver fat by as much as 14–30% relatively, as assessed by imaging methods such as MRI.

Strength training is particularly beneficial for individuals with poor aerobic fitness, as it can be tailored individually according to load and endurance.

 Treating fatty liver is important for those struggling with high cholesterol, as fatty liver impairs the liver's ability to regulate blood fats.When the liver is fatty, it produces more harmful lipids, such as LDL cholesterol and triglycerides, and impairs the function of HDL cholesterol. This directly increases the risk of cardiovascular diseases. By treating fatty liver, cholesterol balance can be improved, protecting both the heart and the entire metabolism.

The benefits of strength training are most visible when the training is regular and sufficiently challenging:

•  Frequency: 2–3 times a week

•  Duration: 30–60 minutes per session

•  Exercises: 6-8 exercises for the whole body

•  Sets and repetitions: 2–4 sets, 8–15 repetitions

•  Load: 50–85 % of 1RM (percentage of one-repetition maximum), progressing gradually

It is important to maintain progressiveness and avoid overloading, especially for beginners.

Strength training should be combined with other healthy lifestyle choices, such as a quality diet, sufficient sleep, and stress management.

Gym training is suitable for everyone, regardless of age, size, or previous experience. The best way to get started is to participate in guided groups organized by the municipality or to hire a personal trainer for the first few sessions. With professional guidance, you will gain confidence in your technique and training program.

When starting out, it is advisable to favor gym equipment that supports movement and helps target the workout correctly. The most important thing is to load large muscle groups, such as the legs, back, and chest, with simple and safe movements.

Remember: the gym is for everyone, and everyone has the right to start from their own level. Small steps towards a stronger and healthier feeling!

Strength training is a safe, effective, and easily customizable way to improve LDL cholesterol, insulin sensitivity, and liver health. Although direct evidence of reversing liver fibrosis through exercise is still limited, everything suggests that strength training slows the progression of fibrosis and improves overall liver function.

Considering its extensive health benefits and minimal drawbacks, strength training deserves a place in every toolkit aimed at improving metabolic health.