Quick Answer
The three strategies with the strongest evidence for raising metabolic rate: resistance training to build muscle (the primary long-term lever), high-intensity exercise for EPOC (short-term post-exercise burn elevation), and adequate protein intake (highest thermic effect of any macronutrient). Supporting these with consistent daily movement, quality sleep, and appropriate calorie intake amplifies the effect. Most “metabolism boosting” supplements and foods produce effects too small to measure meaningfully in real life.
What Metabolism Is (and What You Can and Can't Change)
Metabolism is the sum of all chemical processes in the body that convert food and drink into energy. For practical purposes, it breaks into three components:
Basal metabolic rate (BMR). The energy your body burns at complete rest to maintain basic functions — breathing, circulation, cell repair, temperature regulation. BMR represents 60–70% of total daily energy expenditure for most people and is primarily determined by genetics, body size, sex, and age. This portion is largely not alterable through lifestyle. Research from Duke University’s Global Health Institute puts it plainly: there is no method to boost BMR “in a way that’s durable or real” beyond the muscle mass effect described below.
Thermic effect of food (TEF). The energy burned digesting and metabolising food. Accounts for roughly 10% of daily energy expenditure. TEF is influenced by macronutrient composition — protein costs the most to process (15–30% of its calories), followed by carbohydrates (5–10%) and fat (0–3%).
Activity thermogenesis. All calories burned through movement — both formal exercise and non-exercise activity thermogenesis (NEAT). This is the most variable and most influenceable component. NEAT — fidgeting, walking, standing, incidental movement — can account for 15–30% of total daily energy expenditure and varies enormously between individuals. Two people with identical body sizes can differ by 2,000 calories per day in NEAT.
The important implication: most strategies that meaningfully affect total daily calorie expenditure work through activity thermogenesis — specifically exercise and daily movement — rather than through changing the underlying metabolic rate. The goal is less about “boosting metabolism” and more about structuring training and daily habits to maximise total calorie expenditure and build the muscle mass that elevates resting burn long-term.
Strategy 1: Build Muscle Through Resistance Training
This is the most evidence-backed long-term metabolic strategy available. Muscle tissue is metabolically active at rest — it burns approximately 6–7 kcal per pound per day just existing, compared to roughly 2 kcal per pound for fat tissue. More muscle mass means a higher resting metabolic rate, persistently, around the clock.
The effect compounds with age. Research shows muscle mass decreases at roughly 3–8% per decade from the 30s onward. As muscle is lost and fat increases, resting metabolic rate falls — not because metabolism itself slows, but because the body composition has shifted toward less metabolically active tissue. This is the primary mechanism behind the apparent “metabolic slowdown” that many people notice in their 30s and 40s. Resistance training arrests and reverses this shift.
Resistance training also produces EPOC — excess post-exercise oxygen consumption. After an intense strength session, the body continues burning calories at an elevated rate for several hours as it restores oxygen levels, repairs muscle tissue, and clears metabolic byproducts. The magnitude of EPOC is proportional to session intensity and volume.
Practically: two to three resistance training sessions per week, targeting major muscle groups, is sufficient for meaningful muscle maintenance and development. The specific exercises matter less than progressive overload — gradually increasing load or volume over time — and consistency across weeks and months. Our strength training guide for runners covers the most relevant exercises for endurance athletes who want metabolic and performance benefits from resistance training.
Strategy 2: Include High-Intensity Training for EPOC
High-intensity interval training (HIIT) produces a larger post-exercise calorie burn than moderate-intensity steady-state cardio through the EPOC effect. The harder the session, the longer and more pronounced the elevated post-exercise metabolic rate. Research from Harvard Health confirms that HIIT “may elevate metabolism for some time after a workout” — the exact duration varies but typically 2–6 hours for a hard session.
The practical implication: a 40-minute HIIT session burns more total calories (during and after) than a 40-minute easy jog, even if the during-session calorie burn is similar. The accumulated EPOC effect across a week of training is meaningful, particularly for athletes who include two or more high-intensity sessions per week.
HIIT also builds or preserves muscle mass to a greater degree than low-intensity steady-state exercise, contributing to the long-term resting metabolic rate effect of strategy 1. Our guide on interval running benefits covers what these sessions look like in practice for runners.
One important caveat: the body adapts to exercise volume over time. Research from Duke University suggests that simply increasing training volume can trigger compensatory reductions in NEAT — the body unconsciously moves less the rest of the day to offset the extra exercise calories burned. This is one reason why adding more exercise volume doesn’t always produce proportional weight loss: the total energy expenditure is partially offset by reduced incidental movement. The quality and intensity of exercise matters more than simply adding more hours.
Strategy 3: Prioritise Protein at Every Meal
Protein’s thermic effect — the calorie cost of digesting it — is substantially higher than carbohydrates or fat. A diet higher in protein therefore burns more calories through digestion, all else equal. According to research published in Nutrition & Metabolism, protein increases calorie expenditure by 15–30% of its energy content during digestion. For a 150-gram daily protein intake (approximately 600 kcal), this represents 90–180 extra calories burned per day through TEF alone compared to a lower-protein diet.
Protein also directly supports muscle protein synthesis — the process by which the body builds and repairs muscle tissue. Combined with resistance training, adequate protein intake is the most direct lever for building muscle mass and therefore raising resting metabolic rate. Research led by Professor Luc van Loon at Maastricht University suggests consuming protein close to both exercise sessions and sleep — casein protein before bed, for example, can increase overnight amino acid availability and muscle reconditioning.
Target: 1.6–2.2 grams of protein per kilogram of body weight per day is the range most consistently supported by research for athletes engaged in regular training. This is above general population recommendations and reflects the additional protein demands of muscle synthesis and repair during training.
Strategy 4: Maximise Daily Movement (NEAT)
Non-exercise activity thermogenesis — all the movement that isn’t formal training — is the most variable and underappreciated component of daily calorie expenditure. Research shows NEAT can range from near zero (extremely sedentary) to over 2,000 calories per day (physically active occupation) in individuals of similar body size. This enormous range is why two people following the same training plan can have dramatically different total daily energy expenditure.
Practical NEAT-increasing habits include standing rather than sitting for part of the working day, walking rather than driving for short errands, taking stairs, and generally choosing the more physically active option for routine activities. Running 3km daily is one of the simplest structured NEAT additions — 20–25 minutes of movement that accumulates meaningful calorie expenditure across a week with low injury risk. Our guide on slow jogging vs fast walking covers how even low-intensity daily movement contributes to total energy expenditure and metabolic health.
The NEAT lever is particularly important for people with desk-based jobs. An hour of formal exercise cannot undo the metabolic effect of nine hours of sitting, but structured movement breaks distributed throughout the day can substantially close the gap.
Strategy 5: Don't Severely Restrict Calories
Aggressive calorie restriction is one of the most reliable ways to lower metabolic rate — directly counterproductive to the goal of a faster metabolism. When calorie intake is reduced sharply, the body interprets the deficit as a potential starvation threat and lowers BMR in response — reducing thyroid hormone output, lowering body temperature slightly, and reducing NEAT unconsciously. This metabolic adaptation (sometimes called “adaptive thermogenesis”) is why crash diets produce rapid initial weight loss followed by a plateau, and why weight is regained rapidly when normal eating resumes.
The research is clear on this: moderate, sustained calorie deficits (250–500 kcal/day) combined with resistance training preserve muscle mass and metabolic rate far more effectively than aggressive restriction. The muscle preservation is critical — most weight lost through severe restriction includes significant muscle mass, which directly lowers resting metabolic rate and makes subsequent weight management harder.
For athletes specifically, adequate calorie intake matters for training quality. Underfuelling impairs the ability to train with sufficient intensity to produce EPOC and maintain muscle mass — undermining both the primary metabolic levers simultaneously.
Strategy 6: Prioritise Sleep Quality
Sleep deprivation affects metabolism through multiple pathways. Research shows that insufficient sleep reduces levels of leptin (the satiety hormone) and increases ghrelin (the hunger hormone), producing appetite dysregulation independent of actual calorie needs. A 2019 study found that four or more consecutive nights of inadequate sleep slightly decreased the body’s ability to metabolise fat. Sleep restriction also elevates cortisol, which promotes fat storage, particularly visceral fat around the abdomen.
The sleep-metabolism connection is particularly relevant for endurance athletes who train hard and recover poorly. Training hard on inadequate sleep simultaneously impairs recovery, reduces training quality, increases cortisol, and disrupts the hormonal environment for muscle building — all of which negatively affect metabolism. Seven to nine hours of sleep per night is the range most consistently associated with optimal metabolic health and athletic recovery in the research.
Strategy 7: Stay Hydrated
Adequate hydration has a modest but real effect on metabolic rate. Research shows drinking approximately 500ml of water produces a temporary 10–30% increase in metabolic rate for 30–40 minutes, likely through the thermogenic effect of warming the ingested water to body temperature. While this effect is small in the context of a full day’s calorie expenditure, chronic mild dehydration has been associated with impaired exercise performance, reduced NEAT, and lower training quality — all of which indirectly suppress the primary metabolic levers.
Practically, hydration status affects training intensity more than metabolic rate directly. Athletes who train dehydrated perform worse, which reduces EPOC and training-induced muscle stimulus. Consistent hydration supports the exercise quality that underpins genuine metabolic improvement.
Strategy 8: Zone 2 Training for Metabolic Efficiency
Zone 2 aerobic training — sustained easy effort at roughly 55–75% of maximum heart rate — improves the body’s ability to oxidise fat as a fuel source. This fat-burning efficiency, sometimes called FatMax, is not the same as “boosting metabolism” in the conventional sense, but it has meaningful practical implications: athletes with higher fat oxidation capacity can sustain longer efforts at lower perceived exertion, preserving glycogen stores for harder efforts and reducing fatigue at moderate intensities.
BBC Science Focus reports that research suggests pre-breakfast aerobic training in a glycogen-depleted state can raise FatMax by forcing the body to adapt to fat as a primary fuel. While the evidence for this specific protocol is not conclusive, the broader principle — that consistent aerobic training in Zone 2 improves metabolic efficiency — is well-established. Our zone 2 running guide covers how to train at this intensity and our guide on zone 2 and VO2 max addresses how aerobic base development interacts with fitness and metabolism.
What Doesn't Work (or Works Much Less Than Claimed)
Metabolism-boosting supplements. Caffeine produces a temporary 5–20% increase in metabolic rate for 2–3 hours. Green tea catechins (EGCG) have shown a small effect on resting metabolic rate in some trials, particularly at 100–300mg doses. These effects are real but small — and the body adapts to caffeine over time, reducing the effect with regular use. Most other marketed supplements have no meaningful evidence.
Spicy foods (capsaicin). Research confirms a small thermogenic effect from capsaicin (the compound in chilli). The effect is real and tiny — unlikely to be meaningful in the context of total daily calorie expenditure for most people.
Frequent small meals. The idea that eating frequently “keeps the metabolism stoked” is not supported by research. Meal frequency does not meaningfully affect total metabolic rate when total calorie and protein intake are matched. The thermic effect of food is determined by total food intake, not how it’s distributed across meals.
Detox teas and cleanses. No evidence of meaningful metabolic effect. Many contain laxatives that produce temporary weight loss through fluid loss, not fat loss or metabolic change.
The honest summary from Scientific American and similar sources: most things marketed as metabolism boosters fall into two categories — dangerous stimulants and ineffective products. The strategies with genuine evidence are the ones covered above — resistance training, high-intensity exercise, protein intake, daily movement, sleep, and appropriate calorie intake. These are less exciting to market but produce durable results.
Putting It Together: A Week That Supports Metabolic Health
| Strategy | Metabolic mechanism | Evidence strength | Practical action |
|---|---|---|---|
| Resistance training | Builds muscle mass → raises resting BMR; EPOC | Strong | 2–3 sessions/week, progressive overload |
| High-intensity exercise (HIIT) | EPOC — elevated post-exercise calorie burn | Strong | 1–2 hard sessions/week alongside easy training |
| Adequate protein intake | High thermic effect; supports muscle synthesis | Strong | 1.6–2.2g per kg bodyweight daily |
| Daily movement (NEAT) | Largest variable component of daily energy expenditure | Strong | Walking, standing, 3km daily run |
| Avoid severe calorie restriction | Prevents adaptive thermogenesis / muscle loss | Strong | Moderate deficit of 250–500 kcal max if dieting |
| Quality sleep (7–9 hrs) | Regulates hunger hormones, cortisol, fat metabolism | Moderate–strong | Consistent sleep schedule, sleep hygiene |
| Zone 2 training | Improves fat oxidation efficiency (FatMax) | Moderate | 2–3 easy aerobic sessions/week |
| Hydration | Supports training quality; small direct thermogenic effect | Moderate | Consistent hydration, especially around training |
| Caffeine/green tea | Small temporary metabolic rate increase | Small effect | Not a meaningful lever for most people |
| Spicy foods | Small thermogenic effect | Very small | Add to diet but don't rely on as a strategy |
For athletes already engaged in structured training, the most impactful changes are often not adding more exercise volume but ensuring the training that already exists is supported by adequate protein, appropriate sleep, and consistent daily movement. Our guides on running frequency and the science of running frequency cover how training distribution affects long-term adaptation — relevant to the metabolic question of how to get the most from the exercise you’re doing. For older athletes particularly, our running over 60 guide covers how to maintain the muscle mass and aerobic fitness that underpin metabolic health as the natural age-related decline begins.
Build the Training Habits That Drive Metabolic Health
Consistent structured training — combining easy aerobic work, intervals, and strength — is the most durable way to support a healthy metabolism. A training plan takes the guesswork out of the balance.
FAQ: How to Boost Metabolism
Can you actually boost your metabolism?
Within limits, yes. You cannot dramatically change basal metabolic rate, which is primarily set by genetics and body size. What you can meaningfully influence is muscle mass (which raises resting calorie burn), post-exercise EPOC from hard training, and daily movement (NEAT). These are durable, cumulative effects — not the quick fixes marketed by supplement companies.
Does strength training boost metabolism?
Yes — this is the most evidence-backed strategy. Muscle burns approximately three times more calories at rest than fat tissue. Building muscle through resistance training raises resting metabolic rate permanently (as long as the muscle is maintained), and produces EPOC that elevates calorie burn for hours after each session.
Does HIIT boost metabolism?
Yes, through the EPOC effect. High-intensity exercise produces a larger and longer post-exercise calorie burn than moderate-intensity training. HIIT also builds or preserves muscle mass, contributing to long-term resting metabolic rate.
Does protein boost metabolism?
Yes. Protein has the highest thermic effect of any macronutrient — the body burns 15–30% of protein’s calorie content just digesting it. Higher protein intake also supports muscle synthesis, the primary long-term metabolic lever.
Does metabolism slow with age?
Not as early as most people believe. Research shows BMR stays relatively stable from age 20 to 60. The decline of ~0.7% per year begins around age 60. The apparent “metabolic slowdown” most people notice in their 30s and 40s is primarily driven by muscle loss from reduced activity, not metabolic rate itself — which is why resistance training is the most important intervention at any age.
