In short:
- Long-term fat loss results are similar with either order when training volume and intensity are equal.
- Cardio before strength training can reduce performance by up to 20–45%, because muscle glycogen is partly depleted.
- Cardio after strength training saves muscle glycogen for the weights and increases the post-workout metabolic boost.
- Your personal goal determines the best choice – if you’re training for body composition, it makes sense to start with strength training.
How does cardio before vs after strength training affect fat loss?
Cardio before vs after strength training is one of the most debated questions in the gym. The research shows that exercise order affects short-term performance and metabolism in different ways, although long-term fat loss results depend mainly on your overall training volume and nutrition. How to eat before and after training is an equally important variable – your nutrition strategy supports both approaches.
What happens to your body when you do cardio before strength training?
If you start with aerobic exercise – running, cycling or a stair climber – part of your muscle glycogen stores is used up before you reach the weights. Studies show that prior endurance training can reduce maximal strength output by up to 20–45% (Wilson et al., 2012). That means squats, deadlifts and pressing suffer: you can’t fatigue the muscles at full strength, which impairs hypertrophy and the post-workout metabolic boost.
The molecular explanation is as follows: intense cardio activates the enzyme AMPK (AMP-activated protein kinase), a catabolic signaling molecule. Muscle protein synthesis, however, requires anabolic signaling through the mTOR pathway. AMPK inhibits the mTOR pathway, so cardio immediately before strength training could in theory interfere with muscle adaptation (Coffey & Hawley, 2007).
Cardio before strength training is still appropriate when cardiovascular fitness or an endurance sport is your priority. The rule is simple: always do the more important training with unfatigued muscles.
What does cardio after strength training do for fat loss?
Doing strength training first lets you work with full muscle glycogen reserves, which means better strength output, greater mechanical load and a stronger EPOC effect (excess post-exercise oxygen consumption – elevated metabolism after training). Studies confirm that strength training raises energy expenditure for up to 38 hours after the session (Schuenke et al., 2002) – this is the so-called afterburn, which cardio of the same intensity does not match to the same degree.
Once the strength workout is done and your glycogen stores are partly depleted, your body switches to oxidizing fatty acids faster during cardio. This effect is especially noticeable with moderate-intensity cardio (50–65% of maximal oxygen uptake), where fat burning is proportionally highest.
Don’t be afraid of strength training – combining cardio and strength exercises gives the best synergy for improving body composition, as long as the order is set according to your goal.
Cardio before vs after – comparison table
| Criterion | Cardio BEFORE strength training | Cardio AFTER strength training |
|---|---|---|
| Strength performance | Decreases by up to 20–45% | Fully preserved |
| Fat burning during cardio | Moderate | Higher (glycogen partly depleted) |
| EPOC afterburn | Lower | Higher (strength training first) |
| AMPK-mTOR conflict | Greater | Smaller |
| Best suited for | Endurance athletes | Trainees focused on body composition |
| Endurance capacity | Developed as a priority | Lower primary focus |
Does exercise order affect long-term results?
In long-term studies (8–12 weeks), no statistically significant difference was found in body fat percentage or muscle mass when training volume and intensity were controlled (Davitt et al., 2014). This suggests that the importance of order shows up mainly through short-term performance and session quality – not so much through the end result.
In practice, this means: if cardio before strength training leaves you unable to load the weights enough (fewer repetitions, lighter weight), your total training load ends up lower and your results poorer. But if the quality of both parts of the session holds up, the difference is minimal.
Eesti Tegijad before and after vividly illustrate that long-term results depend mainly on consistency and proper nutrition – not only on the order of a single training element.
How does nutrition support both approaches?
Regardless of exercise order, macronutrient timing is a key factor. The WHO physical activity guidelines recommend 150–300 minutes of moderate-intensity aerobic activity per week for adults as a baseline level of movement – this creates a framework for sensibly combining cardio and strength training.
Practical advice: eat carbohydrates before strength training so your glycogen stores are full; take in protein after training for muscle recovery; keep your calorie deficit moderate (up to 500 kcal per day) so your body doesn’t slip into a strongly catabolic state. How to eat before and after workouts gives more detailed practical advice on meal timing.
References
- Wilson JM, Marin PJ, Rhea MR, Wilson SM, Loenneke JP, Anderson JC (2012). Concurrent training: a meta-analysis examining interference of aerobic and strength exercises. J Strength Cond Res. 26(8):2293–307. PMID: 22002517
- Schuenke MD, Mikat RP, McBride JM (2002). Effect of an acute period of resistance exercise on excess post-exercise oxygen consumption: implications for body mass management. Eur J Appl Physiol. 86(5):411–7. PMID: 11882927
- Coffey VG, Hawley JA (2007). The molecular bases of training adaptation. Sports Med. 37(9):737–63. PMID: 17722947
- Davitt PM, Pellegrino JK, Schanzer JR, Tjionas H, Arent SM (2014). The effects of a combined resistance training and endurance exercise program in inactive college female subjects: does order matter? J Strength Cond Res. 28(7):1937–45. PMID: 24476744
Frequently asked questions
Does cardio before strength training burn more fat?
Not necessarily. Fat burning during the cardio session itself may be slightly higher, but the EPOC effect is smaller, because the strength workout suffers from fatigue. Total energy expenditure is often lower when the quality of strength training drops.
How long should the break between cardio and strength training be?
Ideally at least 6 hours if both sessions take place on the same day – in that case the AMPK-mTOR signaling conflict has less impact. If such a gap isn’t possible, studies recommend doing cardio after strength training.
Can fat burners amplify the effect of training order?
Some ingredients, such as caffeine, improve performance in both types of training. EFSA has confirmed caffeine’s positive effect on endurance and strength performance. However, no supplement replaces optimal training order or nutrition.
What is the best order for HIIT?
HIIT depletes glycogen stores more intensively than moderate-intensity cardio, which makes HIIT before strength training especially inadvisable if the goal is to build strength. HIIT after strength training is an acceptable option, but adjusting your total training volume is important to avoid overtraining.
Does order matter if I do cardio and strength training in the same session?
Yes. For improving body composition, most studies recommend starting with strength training. If your priority is endurance capacity, start with cardio – the more important training is always done without tired muscles.
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