Browse the evidence

Simultaneous strength and endurance training (concurrent training) results in compromised adaptations compared to single-mode training due to conflicting molecular signaling pathways (Akt-mTOR vs. AMPK-PGC-1).

If your primary goal is to maximize both strength and endurance simultaneously, be aware that you will likely achieve less in both areas than if you focused on one at a time. To mitigate this 'interference effect,' separate your strength and endurance sessions by at least 6-8 hours, or prioritize one modality in a given training block while maintaining the other at a low volume.

Maintaining high plasma glucose concentrations during exercise improves performance through mechanisms other than substrate (glycogen/fat) oxidation rates.

Don't worry about 'saving' your muscle glycogen by eating carbs during exercise. The benefit comes from keeping your blood sugar stable, which likely helps your central nervous system manage fatigue, allowing you to perform better in the final stages of a long workout.

Women exercising in the luteal phase of the menstrual cycle utilize significantly less muscle glycogen and exhibit lower glucose turnover rates compared to women in the follicular phase or men during moderate-intensity endurance exercise.

If you are a female endurance athlete, be aware that during the luteal phase (post-ovulation), your body relies less on muscle glycogen and more on fat oxidation compared to the follicular phase. This shift in fuel economy might allow you to sustain effort differently, but it also means your glucose turnover is lower. You may not need to fuel as aggressively with carbohydrates during long, moderate-intensity sessions in this phase, or you may experience different fatigue patterns due to altered glycogen sparing.

Higher protein intakes (above RDA) do not negatively impact bone mineral density and may actually protect against osteoporosis and hip fractures by increasing calcium bioavailability and IGF-1 release.

You do not need to worry that eating more protein will weaken your bones. In fact, getting enough protein helps your body absorb calcium better and may lower your risk of hip fractures, especially if you are getting enough calcium in your diet.

Treatment with the GLP-1 receptor agonist liraglutide (1.2 mg/day) prevents bone mineral content loss and increases bone formation markers in obese women who have maintained significant weight loss.

If you are an obese woman who has successfully lost weight and kept it off, ask your doctor about GLP-1 medications like liraglutide. This study shows that this medication can protect your bones from the typical loss that happens after weight loss, likely by boosting bone formation markers.

Men experience larger reductions in appetite ratings (hunger, being bothered by hunger, wanting to eat, thoughts about food) compared to women during a 2-year weight loss diet, regardless of whether they follow a low-carb or low-fat diet.

If you are a woman, you might find that hunger and thoughts about food return to baseline levels sooner (around 6 months) than men, who may experience reduced appetite for the full 2 years. This is a biological difference, not a failure of willpower.

Ingesting carbohydrate 30–60 minutes before exercise does not impair performance and may enhance it, despite causing metabolic shifts like increased carbohydrate oxidation and inhibited fat oxidation.

You can safely eat carbohydrates 30–60 minutes before your event. It will not hurt your performance, and it might help. Just ensure you eat enough (e.g., up to 100g) without causing stomach distress. If you are prone to blood sugar crashes, test this in training.

Resistance training alters the time course of fed-state muscle protein synthesis (MPS) by increasing the initial peak amplitude but shortening the duration of elevation, resulting in a lower total synthetic response over 28 hours compared to untrained muscle.

As you get stronger, your muscles become more efficient at handling stress, causing the growth signal (protein synthesis) to peak higher but fade faster. To maximize muscle growth, you must consume protein immediately after training to catch this sharp, short-lived peak, rather than relying on a prolonged, low-level signal.

Resistance training alters the acute response of muscle protein synthesis (MPS) to exercise by attenuating the rise in non-myofibrillar (mixed) proteins while maintaining the synthesis of myofibrillar proteins, effectively refining the synthetic signal toward contractile proteins.

As you get stronger and more trained, your body becomes more efficient at building muscle. It stops wasting energy on non-essential cellular repairs (sarcoplasm) and focuses strictly on building the actual muscle fibers (myofibrils). This means you don't need to train to 'exhaustion' or do excessive volume to trigger growth; your body has refined its response to focus on what matters for size. Stick to progressive overload, but understand that 'more is better' has diminishing returns as you get trained.

Resistance training elevates resting mixed muscle protein synthesis rates by approximately 48% without changing resting myofibrillar protein synthesis rates.

After 8 weeks of training, your body's baseline protein turnover increases, specifically for non-muscle proteins like collagen and enzymes. This doesn't mean you are building more muscle at rest, but rather that your cellular maintenance is more active. This is a sign of adaptation, not necessarily hypertrophy.

Plasma ghrelin concentrations increase significantly during negative energy balance (weight loss) and decrease during overfeeding, indicating that ghrelin acts as a homeostatic signal to defend body weight rather than simply reflecting current energy intake.

Your body uses ghrelin to signal hunger when you are in a calorie deficit and satiety when you are overfed. This is a natural defense mechanism to maintain body weight. Understanding this can help you anticipate hunger cues during weight loss and recognize that these changes are physiological, not a failure of willpower.

Short-term (14-day) unilateral leg immobilization causes a significantly greater loss of specific muscle strength (strength normalized to cross-sectional area) in women compared to men, despite similar levels of muscle atrophy at the fiber and whole-muscle levels.

If you are a woman recovering from an injury that requires immobilization (like a cast or brace), expect to lose more functional strength than your male counterparts, even if your muscle size shrinks by the same amount. This suggests that rehabilitation for women might need to focus more heavily on neuromuscular re-education and strength restoration early on, rather than just waiting for muscle mass to return.

Habitual consumption of tuna or other broiled/baked fish (dietary omega-3 fatty acids) is associated with favorable Heart Rate Variability (HRV) indices, specifically indicating greater vagal tone, moderated baroreceptor responses, and reduced erratic sinoatrial node firing in older adults.

To support heart rhythm health and autonomic balance, aim to consume tuna or other broiled/baked fish regularly (e.g., 1-2 times per week or more). This dietary pattern is associated with improved vagal tone and more stable heart rhythm patterns, which may contribute to a lower risk of cardiac death. Avoid fried fish preparations, as they did not show these benefits.

Both endurance (cycling) and resistance (leg extension) exercise initiate similar early-time course phosphorylation of the Akt-mTOR-S6K translational signaling pathway during the first 60 minutes of recovery, indicating that both modalities stimulate protein synthesis machinery.

If your goal is to stimulate the muscle's internal machinery for growth (protein synthesis), both heavy lifting and steady-state cardio are effective triggers in the hour following exercise. You do not need to choose one exclusively to activate these specific growth signals; both work similarly in the short term.

Low-glycemic index diets reduce the risk of cardiovascular disease and type 2 diabetes by improving lipid profiles (lowering triglycerides, raising HDL) and reducing markers of inflammation and insulin resistance.

To protect your heart and reduce diabetes risk, focus on the quality of your carbohydrates. Choose foods that digest slowly (low GI) like beans, lentils, and whole grains. This helps improve your cholesterol levels (higher HDL, lower triglycerides) and reduces inflammation, offering protection against heart disease and diabetes.

High consumption of white rice (≥450 g/day) is associated with an increased risk of incident type 2 diabetes, with the strongest association observed in South Asian populations.

If you eat large amounts of white rice (more than 3 cups cooked per day), your risk of developing type 2 diabetes increases, especially if you are of South Asian descent. To reduce this risk without necessarily giving up rice, try switching to brown rice, choosing high-fiber white rice varieties, or adding legumes (beans, lentils) to your rice meals to lower the glycemic impact. Be aware that in China, this specific risk was not statistically significant, suggesting regional or varietal differences.

High-intensity aerobic exercise (60% Wmax) sustains myofibrillar protein synthesis (MyoPS) into late recovery (24-28h), whereas low-intensity exercise (30% Wmax) does not, despite both stimulating early recovery MyoPS.

If your goal is to maximize muscle protein synthesis from aerobic exercise, intensity matters more than duration. A 30-minute high-intensity session (60% of your max power) sustains muscle-building signals for up to 28 hours, whereas a 60-minute low-intensity session (30% max power) does not. To get the most out of your cardio for muscle health, prioritize higher intensities, even if the workout is shorter.

High-intensity aerobic exercise stimulates mitochondrial protein synthesis (MitoPS) in late recovery (24-28h), whereas low-intensity exercise does not, although neither intensity stimulated MitoPS in early recovery (0.5-4.5h) in the fasted state.

If you are doing fasted cardio, high-intensity intervals may be more effective than low-intensity steady state for stimulating mitochondrial protein synthesis in the 24-28 hour window after exercise. Low-intensity cardio did not stimulate mitochondrial synthesis in this study, regardless of intensity, in the early recovery phase.

Sustained weight loss via caloric restriction or bariatric surgery resolves hepatic inflammation and improves systemic glucose homeostasis, but fails to reverse adipose tissue inflammation and insulin resistance in a significant subset of patients.

If you have lost significant weight, do not assume your metabolic health has fully recovered. While your liver function and blood sugar control likely improved, your fat tissue may still harbor inflammation and insulin resistance. Continue to monitor metabolic markers (like inflammation and insulin sensitivity) with your doctor, as these may not improve as much as your weight does.

Maintaining tissue n-6 highly unsaturated fatty acid (HUFA) levels below 50% of total HUFA (by shifting the n-6/n-3 balance toward n-3) reduces the risk of coronary heart disease mortality, whereas levels above 50% increase risk.

Focus on balancing your intake of n-6 and n-3 fatty acids. Aim to reduce the proportion of n-6 fatty acids (found in many vegetable oils) relative to n-3 fatty acids (found in fish, flax, walnuts) in your body tissues. This balance is a stronger predictor of heart disease risk than cholesterol levels alone.

Higher circulating levels of dairy fat biomarkers (plasma 15:0, 17:0, and t-16:1n-7) are associated with a significantly lower risk of incident type 2 diabetes.

Instead of avoiding all dairy fat, focus on consuming whole dairy sources like cheese and yogurt, which are associated with specific fatty acids (15:0, 17:0, t-16:1n-7) that correlate with a lower risk of developing type 2 diabetes. This suggests that the source and composition of fat matter more than simply avoiding saturated fat.

Mendelian randomization analysis confirms a causal relationship between diabetes and an increased risk of coronary artery disease, independent of other risk factors like lipids and BMI.

If you have diabetes or high blood sugar, managing your glucose levels is crucial for protecting your heart. Genetic evidence suggests that long-term control of blood sugar can reduce the risk of coronary artery disease. Work with your healthcare provider to find a sustainable glucose management plan.

SGLT2 inhibitors lower HbA1c by 0.6-0.8% without increasing hypoglycemia risk when used as monotherapy, but require dose adjustment of insulin/secretagogues when combined.

SGLT2 inhibitors effectively lower blood sugar (HbA1c) by about 0.6-0.8% without causing low blood sugar on their own. If you are also taking insulin or sulfonylureas, your doctor may lower your dose of those medications to prevent hypoglycemia. This makes them a safer option for many patients compared to older drugs.

Time-restricted feeding (TRF) with early or midday timing improves insulin sensitivity and cardiometabolic health markers more effectively than late TRF, independent of caloric restriction.

If you practice Time-Restricted Feeding, try to eat your meals earlier in the day (e.g., 8 AM to 2 PM or 10 AM to 6 PM). This timing aligns with your body's natural circadian rhythm and has been shown to improve insulin sensitivity and blood pressure more effectively than eating the same calories later in the evening. You do not need to restrict calories strictly; simply shifting your eating window earlier can yield metabolic benefits.