TL;DR
- Training day 2600 kcal / rest day 2200 kcal for an 80 kg male at 2500 TDEE, 18% body fat, on recomposition. Protein flat at 131 g/day; carbs swing 239 to 375 g; fat counter-cycles 64 to 80 g.
- Weekly average 2429 kcal on a 4-training/3-rest week — a 71 kcal/day net deficit relative to 2500 TDEE. Slow recomp territory, not aggressive cut.
- The point is substrate timing, not calorie surplus. Carbs go to training days; fat takes the rest-day calories. Same protein every day.
Macro cycling moves calories around training rather than averaging them flat across the week. The math is simple — same total energy, redistributed against training days — but the resulting daily numbers look very different from a single TDEE printout. Here is what the calculator returns for a typical recomposition scenario.
The scenario
An 80 kg male, 18% body fat, 2500 kcal TDEE, training 4 times per week. Goal: recomposition (lose fat, maintain or slightly gain lean mass). Activity level moderate. The lifter wants a daily macro target that differs between training and rest days rather than a single flat number.
What the calculator returns
Running the inputs through the Macro Cycling Calculator:
Engine input
body_weight_kg = 80
body_fat_pct = 18
goal = recomp
training_days_per_week = 4
tdee = 2500
activity_level = moderate
Engine output
Training day
calories = 2600 kcal
protein = 131 g
carbs = 375 g
fat = 64 g
Rest day
calories = 2200 kcal
protein = 131 g
carbs = 239 g
fat = 80 g
weeklyAvgCalories = 2429 kcal
proteinPerKg = 2.0 g/kg/day
tdeeUsed = 2500 kcal/dayTwo daily templates, used 4 and 3 times per week respectively. Weekly average 2429 kcal — roughly 71 kcal/day under TDEE for a slow recomp. Protein at 2.0 g/kg sits in the middle of the ISSN range for resistance-trained athletes[1].
Reading the numbers
The engine fixes protein at 131 g/day (1.64 g/kg, plus a recomp upcharge) regardless of training day or rest day. Daily protein synthesis runs on a roughly 24-hour cycle independent of yesterday's training; under-eating protein on rest days costs muscle protein balance for the next two days, not just the rest day itself.
Carbs do the cycling. Training days bank glycogen and provide pre/intra/post substrate; rest days have no immediate need for the extra 130+ grams of carbohydrate. Fat counter-cycles: lower fat on training days to leave calorie room for the carbohydrate increase, higher fat on rest days to maintain energy and satiety without breaking the daily total.
Macro distribution
Training day Rest day
─────────────────────────────────────────────────
Protein 131 g 524 kcal (20%) 524 kcal (24%)
Carbs 1500 kcal (58%) 956 kcal (43%)
Fat 576 kcal (22%) 720 kcal (33%)
Total 2600 kcal 2200 kcalThe 400 kcal swing between training and rest days is almost entirely 136 g of carbohydrate substitution against 16 g of fat reduction. The calorie balance comes out: 136 × 4 = 544 kcal of carbs in, 16 × 9 = 144 kcal of fat out, net +400 on training days vs rest days.
Where the formula breaks
Three common breakdowns.
Training intensity mismatch. The 2600 kcal training-day allocation assumes a real training session — 60 to 90 minutes of moderate-to-heavy resistance work, or 90+ minutes of endurance. A "training day" that is 30 minutes of light cardio does not warrant the carbohydrate boost; better to flag those as rest days for the macro plan. The engine does not know what the session looked like; the lifter does.
Bodyweight error. The engine fixes protein at 1.64 g/kg of input bodyweight. For an 80 kg lifter at 18% body fat, fat-free mass is 65.6 kg. Some practitioners argue protein should be 2.2 to 2.4 g/kg of fat-free mass instead — that maps to roughly 145 g/day. The 131 g/day target is on the conservative end; for an aggressive cut, raising protein to 150 g/day at the expense of carbs is defensible.
TDEE input is stale. Two weeks of consistent intake at 2429 kcal/day either holds weight, drops, or gains. If weight drops more than 0.3 kg/week, the input TDEE was below truth; if it rises, TDEE was above truth. The engine produces a starting plan; bodyweight trend across 14 to 21 days validates it.
A practical day plan against these targets
The macro totals translate into food more concretely with a sample day. Training day, 2600 kcal:
Meal 1 80 g oats, 250 ml skim milk, 1 scoop whey,
1 banana, 30 g almonds 620 kcal 35P 80C 18F
Meal 2 200 g chicken breast, 200 g rice, 200 g
broccoli, 15 ml olive oil 680 kcal 50P 75C 18F
Pre-tr. 1 medium banana, 30 g rice cakes 180 kcal 2P 40C 1F
Post-tr 200 g lean ground beef, 250 g potato,
100 g vegetables 580 kcal 40P 50C 17F
Meal 4 200 g Greek yogurt, 50 g berries, 30 g
honey, 1 tbsp peanut butter 340 kcal 20P 50C 10F
Snack 1 protein bar (light) 200 kcal 20P 22C 4F
Daily totals 2600 kcal 167P 317C 68FThe sample lands within 5 g of each macro target — protein slightly over, carbs slightly under, fat on target. The 30 to 40 g of protein per meal pattern catches the per-meal maximum-effective dose for muscle protein synthesis and spreads it across the day. Rest days drop the pre- and post-training meals, swap the second meal's rice for an extra portion of vegetables, and increase fat through nuts, oils, or a heavier breakfast component.
Cross-checking against simpler approaches
A flat 2429 kcal/day at 131 g protein, 290 g carbs, 75 g fat — averaging the macro cycling plan — produces nearly identical body-composition outcomes for most lifters over 8 to 12 weeks. The mechanistic argument for cycling is performance (better training-day fueling) and adherence (rest-day calorie reduction is easier to live with than a flat constant deficit)[2]. Body-composition outcome is similar either way.
For the cycled version to outperform the flat version, training days need to actually use the extra carbohydrate — which means sessions long enough or hard enough to deplete muscle glycogen. The Macro Calculator produces the flat-average equivalent for direct comparison.
Related tools and follow-ups
- Macro Cycling Calculator — the engine used here.
- Macro Calculator — flat-day equivalent at the same TDEE and goal.
- Protein Intake Calculator — independent cross-check on the 131 g/day protein target.
For broader context: Body recomposition for lifters: the calorie math, Carb periodization: the hybrid athlete math, and How to count macros cover the broader macro framework.
FAQ
What does the macro cycling engine return for an 80 kg male at 2500 TDEE on recomp? Training-day 2600 kcal (131 g protein, 375 g carbs, 64 g fat). Rest-day 2200 kcal (131 g protein, 239 g carbs, 80 g fat). Weekly average 2429 kcal across four training days and three rest days.
Why does protein stay flat while carbs and fat swing? Daily protein at 1.6 to 2.2 g/kg of bodyweight maximizes muscle protein synthesis whether training that day or not. Carbohydrate and fat are interchangeable energy substrates; carbs go up on training days to support glycolysis, fat goes up on rest days to maintain satiety and total energy.
What is the calorie surplus on training days? +100 kcal on training days (2600 vs 2500 TDEE). The rest day deficit is -300 kcal. Weekly net deficit is roughly 500 kcal across seven days, which supports slow fat loss while preserving training-day performance.
References
- 1 International Society of Sports Nutrition position stand: protein and exercise (Jäger et al.) — Journal of the International Society of Sports Nutrition (2017)
- 2 Carbohydrate availability and athletic performance (Burke et al.) — International Journal of Sport Nutrition and Exercise Metabolism (2018)
- 3 Methodology — Macro Cycling Calculator — AI Fit Hub