Browse the evidence

A typical hatha yoga session (averaging 2.5 METs and 49.4% max heart rate) does not meet the intensity recommendations for improving or maintaining cardiovascular fitness.

If your goal is to improve cardiovascular fitness or meet standard health activity guidelines, a standard hatha yoga class is likely not intense enough on its own. While yoga offers many health benefits, you should pair it with other activities that elevate your heart rate to at least 50-60% of your maximum (moderate intensity) to ensure you are getting the cardiovascular benefits recommended by health organizations.

Sun salutation postures within a yoga session can reach moderate intensity levels (approx. 3.0 METs and 55% max heart rate), potentially contributing to cardio-respiratory fitness in unfit individuals.

If you practice yoga, focus on the dynamic sequences like Sun Salutations. These specific poses can reach moderate intensity levels suitable for cardiovascular health, especially if you are new to exercise. However, be aware that this intensity level may not be sufficient for maintaining fitness if you are already physically fit.

Exercise training reduces serum leptin levels in older women, but this reduction is driven by the loss of fat mass rather than an independent effect of exercise or hormone replacement therapy.

If you are an older woman exercising to lose fat, expect your leptin levels to drop. This is a normal and expected result of losing fat mass, not a negative side effect of the exercise itself. Hormone replacement therapy does not appear to alter this outcome.

Local thyroid hormone activation in skeletal muscle via D2 drives a shift from slow-twitch (Type I) to fast-twitch (Type II) fibers, increasing energy expenditure and influencing insulin sensitivity.

Skeletal muscle uses local thyroid hormone activation to adjust its metabolic profile. Higher local T3 levels promote fast-twitch fibers and increase energy expenditure through heat production and glucose uptake. This suggests that muscle-specific thyroid regulation plays a key role in metabolic flexibility and insulin sensitivity.

In older obese postmenopausal women, higher visceral adipose tissue (VAT) levels are independently associated with lower glucose disposal (insulin resistance), whereas total fat mass and subcutaneous adipose tissue are not significant predictors.

For older obese women, simply losing total weight may not be enough to improve insulin sensitivity if visceral fat remains high. Focus on strategies that specifically target abdominal/visceral fat, as this tissue type is the primary driver of insulin resistance in this demographic, independent of total body fat or muscle fitness levels.

Standard predictive equations for resting metabolic rate (RMR) overestimate energy requirements in chronic spinal cord injury (SCI) patients by 5–32%, primarily due to reduced fat-free mass and altered sympathetic nervous system activity.

Do not use standard calorie calculators for spinal cord injury. They will overestimate your needs by up to 32%, leading to weight gain. You need a metabolic cart measurement or a validated SCI-specific equation to determine your true resting metabolic rate.

Higher baseline PFAS levels (specifically PFOS and PFNA) are associated with a greater decline in Resting Metabolic Rate (RMR) during the initial weight loss phase and a blunted increase in RMR during the weight regain phase.

This finding explains why some people struggle to keep weight off despite eating less: their metabolism doesn't 'bounce back' as it should. High levels of environmental chemicals (PFAS) may blunt this metabolic recovery. To counteract this, prioritize resistance training to build metabolically active tissue, as this may help override the blunted RMR response caused by environmental factors.

High fat diets increase the contribution of fat to oxidative metabolism at the same relative exercise intensity, raising the crossover point, but may initially decrease endurance performance by lowering muscle glycogen.

Eating a high-fat diet trains your body to burn more fat, allowing you to exercise at higher intensities without depleting sugar stores as fast. However, because your sugar stores are lower, you might feel weaker initially. Long-term adaptation may improve endurance at moderate intensities.

Testosterone supplementation in elderly men increases muscle mass and strength but carries significant side effects, including sleep apnea, thrombotic complications, and prostate cancer risk.

Testosterone therapy can increase muscle mass and strength in elderly men, but it is not a first-line treatment due to serious side effects like prostate cancer risk and blood clots. It should only be considered under strict medical supervision when benefits outweigh risks.

An internet-based guided recovery training integrating cognitive behavioral therapy for insomnia (CBT-I) techniques with psychological detachment and recreational activity planning significantly reduces insomnia severity and work-related strain in stressed employees compared to a waitlist control.

If you are a stressed employee struggling with sleep, consider a structured, online recovery program that combines sleep hygiene, sleep restriction, and techniques to mentally detach from work. Look for programs that offer guidance (coaching) rather than just passive content. Commit to six weeks of weekly modules, tracking your sleep and planning leisure activities to rebuild resources. This approach has shown large improvements in insomnia severity for people with similar profiles.

Short sleep duration (< 7 hours per night) and long sleep duration (> 8 hours per night) are both associated with increased levels of inflammatory markers (IL-6 and CRP) and higher all-cause mortality risk compared to normal sleep (7-8 hours).

Aim for 7-8 hours of sleep per night. Both sleeping less than 7 hours and more than 8 hours is associated with increased inflammation (IL-6, CRP) and higher mortality risk. Prioritize consistent, adequate sleep duration over excessive sleep.

Insufficient or mistimed sleep disrupts circadian gene expression rhythms in peripheral tissues (e.g., liver, blood), leading to metabolic and immune dysregulation, while the central pacemaker (SCN) remains largely unaffected.

Prioritize consistent sleep duration and timing. Disrupting your sleep schedule (e.g., shift work, late sleeping) doesn't just make you tired; it fundamentally alters how your body's genes regulate metabolism and immunity. Protecting your circadian rhythm by sleeping at appropriate times is critical for preventing metabolic syndrome and other long-term health issues.

Mistimed sleep (sleeping during the day) causes a massive arrhythmicity in peripheral gene expression, with 97% of rhythmic genes becoming arrhythmic in humans.

If you must work night shifts or sleep during the day, recognize that your body's gene expression rhythms are severely disrupted. This is not just about feeling groggy; it is a state of molecular desynchronization. Mitigate this by controlling light exposure, timing meals carefully, and prioritizing sleep quality when possible.

Sleep disruption is associated with an increased risk of metabolic syndrome, type-2 diabetes, and certain cancers through mechanisms involving altered gene expression, hormone levels, and immune response.

Prioritize sleep as much as you prioritize diet and exercise. Chronic sleep loss or irregular sleep schedules significantly increase your risk for metabolic syndrome, diabetes, and cancer. Consistent, adequate sleep is non-negotiable for long-term health.

Prolonged-release melatonin (2 mg) significantly reduces sleep latency in elderly patients (aged 65-80) with primary insomnia, with effects sustained over 6 months without tolerance.

If you are over 65 and struggle with falling asleep, a 2mg prolonged-release melatonin tablet taken 1-2 hours before bed, after eating, can help you fall asleep about 19 minutes faster. This benefit lasts for at least 6 months without losing effectiveness. It does not appear to work for younger people with low melatonin levels.

Sleep disturbances are associated with higher all-cause mortality in men, particularly those under 45 years of age, whereas no such association is observed in women.

If you are a man under 45, persistent sleep problems (trouble falling asleep, waking up, or needing medication) are a significant warning sign for premature death. You should prioritize fixing your sleep hygiene and consult a doctor, as this risk is not present in women of the same age group.

Sleep disturbances are strongly associated with an increased risk of suicide in men, with those reporting >=3 disturbances having nearly 5 times the risk.

If you are a man struggling with multiple sleep issues (trouble falling/staying asleep, needing medication), recognize this as a serious risk factor for suicide. Seek medical help for your sleep, as treating it may reduce your risk of self-harm, independent of depression.

Sleep disturbances are associated with a higher risk of developing hypertension and diabetes in both men and women, but do not significantly affect BMI trajectories.

Regardless of your weight, poor sleep increases your risk of high blood pressure and diabetes. Prioritize sleep quality to protect your metabolic health, as these conditions develop silently over time.

Antiretroviral therapy (ART) improves BMI and helps regain muscle mass, but weight loss can still occur in a significant proportion of patients on ART, necessitating concurrent nutritional interventions.

Starting ART is a crucial step, but it does not guarantee weight stability. Many patients continue to lose weight or develop wasting even after starting treatment. To maximize health outcomes, combine ART with a balanced diet, physical activity, and management of side effects to ensure adequate energy intake and muscle preservation.

For adults, an Adequate Intake (AI) of 350 mg/day for men and 300 mg/day for women is sufficient to maintain magnesium homeostasis, based on observed intakes in healthy EU populations.

To maintain optimal magnesium levels, adult men should aim for 350 mg and adult women for 300 mg daily. Achieve this through magnesium-rich foods like nuts, whole grains, legumes, and leafy vegetables rather than relying on supplements.

Activation of G-protein coupled receptor 120 (GPR120) by n-3 fatty acids (DHA, alpha-linolenic acid) attenuates the production of pro-inflammatory cytokines (TNF-alpha, IL-6, MCP-1) and prevents obesity-induced glucose intolerance and insulin resistance.

Incorporate n-3 fatty acids (found in fish, flax, walnuts) into your diet. They activate a specific receptor (GPR120) that reduces inflammation in fat and muscle tissue, helping to prevent insulin resistance, especially if you are prone to obesity.

GH replacement in GH-deficient adults improves exercise capacity (VO2max, ventilatory threshold) and lean body mass, but does not improve performance in healthy normal subjects.

If you are diagnosed with Growth Hormone Deficiency, replacement therapy will likely improve your exercise capacity and lean mass. If you are healthy, taking GH will not improve your performance and carries significant health risks.

In older men without diabetes, higher insulin resistance (measured by HOMA-IR) is associated with accelerated loss of lean mass (sarcopenia) and reduced gain of fat mass over time.

If you are an older man, your metabolic health matters for your muscle mass. High insulin resistance is linked to faster muscle loss and less fat gain. Managing blood sugar and insulin sensitivity through lifestyle changes may help preserve lean muscle mass as you age, independent of physical activity levels.

A 12-week resistance exercise program increases lean body mass and hepatic insulin sensitivity in obese adolescents without causing weight loss or reducing body fat.

If you are obese and sedentary, start a resistance training program twice a week. You don't need to diet or lose weight for this to work. You will likely gain muscle and improve your liver's ability to handle insulin, which is a key metabolic health marker. Don't worry if the scale goes up slightly; that is likely muscle, not fat.