SYNTH-83 · Guide
Popular training claims the base does not support
What to say instead: most magazine staples are untested here or were tested and did not deliver, so every element of a session needs a reason from the base or a practice label
The question it answers
"Do planks make me faster?", "is Zone 2 the fat-burning zone?", "ice bath after every ride?", "is my max HR 220 minus age?", "is soreness a sign it worked?" — and, before adding a filler to a session or repeating a common belief: does the base support it, and what is the honest line instead?
Default (what to prescribe first)
Not from a study; the base's own practice: before adding an element to a session or repeating a popular claim, find the entry that gives it a reason. Template fillers (core circuits, stretching blocks, recovery gadgets, gels on short rides) are left out, or kept and labelled practice or comfort. Say "the base has no trial showing X" or "X was tested and did not do Y in <population>", never "X is a myth" where the base holds no test.
Decision — the claims
| Popular claim | What the base shows | Say / do instead (cited where sourced; otherwise the base's practice via the linked framework) | Source and level |
|---|---|---|---|
| Core work (planks etc.) makes you faster on the bike or run | Pooled RCTs, healthy people over 12: core training improved balance (ES 1.17) and vertical jump (0.69); no economy, time-trial or cycling outcome was pooled. 21 male college athletes, 8 weeks: plank time rose in the core group, running economy did not differ from controls. The entry calls transfer to endurance performance weak and inconsistent (it mentions one small trial with a faster 5000 m and unchanged mechanics, one with unchanged economy). A speed gain is not shown | Core work for trunk control or balance if wanted, after heavy lifting (SYNTH-43, SYNTH-44); never promise speed | REF-1018 A-; REF-1019 B-; no trial in cyclists |
| Zone 2 is the fat-burning zone and trains fat oxidation best | 32 obese adults, 3 months: maximal fat oxidation rose only after HIIT, not after moderate continuous training (intensities not in the abstract; reading it as Zone 2 is the entry's inference). A narrative review: current evidence does not support Zone 2 as the optimal intensity for mitochondrial or fat-oxidative capacity. Superiority not shown | Easy work earns its place through volume and low cost (SYNTH-51), not a unique fat-burning effect | REF-1091 B+ (not athletes); REF-1092 B+ (general population) |
| Compression, cold water, cryo or massage make the next session better | 16 RCTs, 273 competitive/elite endurance athletes (network): no modality beat passive recovery on sport-specific performance (the soreness and CK networks were too thin and heterogeneous to judge either way); compression SMD 0.04 for performance; a sham bath ranked as high as most. Mostly non-elite pools: massage best for DOMS; compression aided recovery (next-day cycling at one 24-h point, ES 1.05); one cold immersion lowered CK and soreness at 24 h, not strength (g 0.08) or jump (g −0.02) recovery. Regular cold water reduced strength gains (SMD −0.60), with no measurable effect on aerobic gains (SMD −0.07 and 0.00; the endurance subset of 8 small studies, intervals wide) | "They may make your legs feel better; a better next session is not shown in competitive endurance athletes (compression null at moderate certainty; the one positive next-day cycling point is from mixed pools)." Food, sleep and an easy day first (SYNTH-70); no cold water after a lift meant to build | REF-1090 A-; REF-385 A; REF-387 A; REF-250 A; REF-914 A- |
| Static stretching prevents injuries; stretch before training | 25 RCTs, 26 610 participants, general sport: stretching did not reduce injuries (RR 0.963, 0.846-1.095); strength programmes did (RR 0.315). Static stretching cost −3.7% immediately afterwards, holds ≥60 s −4.6% vs −1.1% under 60 s; with dynamic activity afterwards no clear cost remained | Injury prevention = strength work (SYNTH-73); stretch for range of motion; before sessions holds under 60 s, then dynamic work (SYNTH-66) | REF-861 A-; REF-268 A |
| Stretching or massage loosens "tight", stiff muscles | Six weeks of static stretching raised ankle range from 30.9° to 36.3° with muscle and tendon stiffness unchanged — stretch tolerance (49 volunteers). A 16-min massage did not change passive stiffness vs sham after downhill running (18 male recreational runners). Foam rolling may lower stiffness and raise range (49 studies, not pooled) | Stretching buys range, massage comfort; stiffness after hard work mostly passes with time (SYNTH-11) | REF-382 A-; REF-317 B+; REF-378 A- |
| 220 − age (or any age formula) gives your max HR | 5069 endurance athletes (abstract count; 5311 in the Results, corrected 2026-10-12) tested to exhaustion: 9 of 13 formula-mode combinations differed significantly from measured HRmax, every formula carried RMSE 9.1-10.5 bpm; 220 − age was among the closest on average in this cohort. 208 − 0.7 × age is a line through group means, no individual error reported (healthy adults) | Any formula = ±10 bpm for one person; anchor zones on a measured max or a threshold HR from a hard field effort (SYNTH-38) | REF-3494 B+; REF-1082 B+ |
| Lactic acid causes the burn, fatigue and next-day soreness; lactate is waste | Narrative reviews: lactate is a fuel and signal shuttled under fully aerobic conditions; the lactate/H⁺ account of fatigue is "probably of limited importance in mammals" (mostly isolated animal muscle). Faster clearance with an active cool-down did not bring less soreness and was largely ineffective for next-day performance (some studies reported a next-day benefit) | Lactate is fuel and a production-clearance balance; no "flushing it out"; soreness has its own time course (SYNTH-11) | REF-172 B+; REF-493 B+; REF-455 B+; REF-913 B+; no entry tests lactate against soreness directly |
| Fasted training burns more fat, so it makes you faster | 17 trained male cyclists, one session: fasted raised fat oxidation with the same interval power (367 ± 51 W). Train-low raised signalling (73% of 11 studies) and oxidative enzymes (78% of 9) but improved performance in only 37% of 11; pooled periodised carbohydrate restriction in endurance-trained athletes: SMD 0.17 [−0.15, 0.49], p = 0.29. A performance gain is not shown | Optional on easy sessions only, never before key sessions; promise a metabolic signal, not a faster race (SYNTH-69) | REF-157 B+; REF-543 B+; REF-218 A- |
| A big calorie surplus is needed to build muscle | Trained lifters, 8 weeks, 17 completers: a 15% surplus gave no clear extra muscle thickness or squat 1RM over maintenance or 5%, but more skinfold gain. 39 young elite athletes: a counselled surplus raised weight more than ad libitum eating, which also gained (3.9% vs 1.5%), mostly as fat (+15% vs +3% fat mass); lean-mass gain did not differ | Heavy lifting and protein; at most a small surplus (a review suggests 0.1-0.25% body weight a week); inference: extra fat is weight on every climb | REF-1088 B; REF-1089 B+; REF-1094 C+ |
| You build muscle in any calorie deficit | Meta-analysis of RCTs ≥3 weeks: in a deficit strength gains were comparable (ES −0.31, p = 0.28), lean-mass gains impaired (ES −0.57); a between-study meta-regression put ~500 kcal/day as enough to stop lean-mass gain | In a weight-loss phase the gym keeps strength and protects muscle (the authors: avoid deficits over ~500 kcal/day); slow loss, key sessions fuelled (SYNTH-54) | REF-1087 A (lifters) |
| A 2 or 4 mmol threshold is a fixed number across meters | Four handheld meters read −7%, 7%, −10% and 42% against a Biosen reference (0.88-4.89 mM); 95% prediction intervals 0.60-0.87 mM wide at 3 mM; a second lab analyser read −32% | Compare readings only on the same meter and protocol; a "4 mmol" zone is device-specific (the entry's inference) | REF-1081 B (venous samples) |
| More protein always builds more; it must come in a post-workout window | 49 RCTs with resistance training: protein added fat-free mass up to ~1.62 g/kg/day total, nothing beyond. For endurance athletes a review advocates ~1.8 g/kg/day, more on rest and train-low days, and finds endurance per-meal targets not established beyond a preliminary ~0.5 g/kg per meal from a single study (corrected 2026-10-12). 116 RCTs in lifting adults (network): post-exercise protein gave the largest fat-free-mass gain (+0.54 kg vs placebo); no timing improved functional performance | Daily total first, spread over the day; timing is a smaller lever in the base's reading (SYNTH-69: timing not shown to change adaptation when daily totals are met; REF-154's post-exercise effect is against placebo, in lifters) | REF-579 A; REF-151 A (narrative); REF-154 A |
| Carb-load before every race; take carbohydrate on every ride | Loading helped only in events over 90 min (2-3% set-distance performance), not under 5 min or at 60-90 min. The UCI statement scales intake: 40-75 min a mouth rinse, 1-2.5 h 30-60 g/h | Fuel by duration and the day's demand (SYNTH-02); load only for events over ~90 min; fuel every key session (the base's practice, SYNTH-69) | REF-819 B+ (narrative); REF-748 A (written for professionals) |
| High-dose vitamin C and E speed recovery | 54 young adults, 11 weeks: 1000 mg vitamin C + 235 mg vitamin E daily stopped the rise in mitochondrial markers (COX4 +59% on placebo vs −13%); VO2max rose 8% in both. Recovery was not measured; no performance benefit shown | No routine high-dose antioxidants in build phases (SYNTH-67); food was not tested | REF-908 A- |
| You must train to failure to get strong | 22 young men, squats: sets stopped at 20% velocity loss gave the same 1RM gain as 40% with 40% fewer reps and a larger jump gain (9.5% vs 3.5%). 51 trained men: 20% gave the largest 1RM gains, 40% the smallest. 43 trained rowers: moderate-volume lifting short of failure gained more bench-pull strength, and both short-of-failure arms more 20-min row power, than higher-volume lifting to failure (volume confounded) | Heavy, few reps, stop when a rep clearly slows (SYNTH-43, SYNTH-44) | REF-584 B+; REF-1085 B+; REF-640 A- |
| Next-day soreness means the session worked ("no pain, no gain") | One eccentric bout protects against damage from later bouts; the least accustomed suffer most downhill damage (narrative reviews). In cycling, muscle damage lowered sprint and incremental peak power and raised RPE at the same power; time-trial performance did not change. No entry links soreness to the size of an adaptation: not shown | Judge a session by whether it hit its targets; expect soreness after new work and less with repetition; keep sprints and max tests off fresh damage (SYNTH-11) | REF-549 B+; REF-660 B+; REF-701 A |
| Cramps come from dehydration or low salt, so salt or more water prevents them | The dehydration and electrolyte explanations rest on anecdote, 18 case reports and one case-control study of 10, and four prospective cohorts do not support them; risk factors include cramp history, fatigue, heat and humidity and novel or harder exercise, sweat losses minor for most | Stretch gently until it releases and ease off; then pacing, conditioning and heat (SYNTH-68); no salt or extra water as the fix | REF-232 B+; REF-233 B+ (both narrative) |
When NOT to use it / nuance
A specific aim can justify the tool. The Copenhagen adduction cut groin-problem prevalence from 21.3% to 13.5% (OR 0.59) in 652 male semi-professional footballers (REF-1020, A-; runners and cyclists are extrapolation): fair for an athlete with groin trouble, said as football evidence.
Easy volume stays: rejecting "Zone 2 burns fat best" is not rejecting easy riding (SYNTH-51).
An age formula is allowed as a labelled estimate when nothing is measured, with ±10 bpm stated (REF-3494).
Do not overcorrect: "not shown" is never "useless" or "a myth".
What the evidence does and does not show
Tested, A/A-: the stretching, recovery-tool, protein-ceiling, antioxidant and deficit rows. Tested, B+/B and indirect: HRmax formulas, lactate meters, surplus, failure.
Not tested: that core work or Zone 2 placement make an endurance athlete faster, or fasted sessions on their own (periodised carbohydrate restriction, which includes them, was tested in endurance-trained athletes: no pooled performance gain, REF-218); that soreness predicts adaptation; that lactate causes soreness — absences or narrative positions, not tested negatives.
Evidence gaps
No core-training trial in cyclists, and none as its own entry with an endurance-performance outcome; REF-1019 (null economy, no performance test) mentions one small trial with a faster 5000 m and one with unchanged economy.
No fat-oxidation training trial comparing easy and hard work in trained endurance athletes (REF-1091 is obese adults).
No entry measures whether soreness, or its absence, predicts the adaptation to a session.
No entry tests blood lactate against delayed soreness directly.
Massage or compression and training adaptation: no entry; cold water and endurance adaptation rests on the endurance subset of eight small studies, with wide intervals (REF-914).
Protein timing in endurance athletes; REF-154 is lifting adults.
How this entry was checked and changed
Why this level
(rows rest on A to B- entries; the strongest are A/A- results for recovery tools, stretching, protein and antioxidants; the weakest load-bearing rows are narrative B+ reviews (lactate, cramps, soreness), a B device study (meters), B/B+ trials and a C+ review (surplus) and a B- trial (core); many trials are in non-athletes or lifters, and the Default rule is the base's own practice)
Content correction 2026-09-27
Verification 2026-10-06: about 60 cited claims checked against KB.md (45 entries, all with a DOI or PMID; no SOURCE flags).All numbers match the entries (core ES 1.17/0.69; stretching RR 0.963/0.315 and −3.7/−4.6/−1.1%; ROM 30.9→36.3°; HRmax 9 of 13 and RMSE 9.1-10.5; meters −7/7/−10/42% and −32%; fasted 367 ± 51 W, 73%/78%/37%, SMD 0.17; surplus 3.9 vs 1.5% and +15 vs +3%; deficit ES −0.31/−0.57 and ~500 kcal; protein 1.62, 1.8 and +0.54 kg; COX4 +59/−13%; VL20 jump 9.5 vs 3.5%; Copenhagen 21.3→13.5%, OR 0.59; CWI g 0.08/−0.02; compression ES 1.05; SMD −0.60/−0.07/0.00).Only one number is wrong, the '8 small studies' attribution (a scope error, not a value).
Verification 2026-10-06: populations are named in nearly every row (obese adults, lifters, general sport, college athletes, footballers, 54 young adults). The worst failure the brief named, 'false' for 'not shown', occurs only in the recovery row's soreness/CK clause and in the core row's 'Not shown' beside an entry that reports one positive small trial. Both are fixed by narrowing.
Verification 2026-10-06: Level B- is fair. The Default is labelled practice; the weakest load-bearing rows are B- (core), B (meters), C+ (surplus rate number, now disclosed) and narrative B+ (lactate, cramps, soreness). No LEVEL-OVERALL.
Verification 2026-10-06: consistency with SYNTH-11 (stiffness passes with time; massage comfort; sprints off fresh damage), SYNTH-38 (an age formula only as a labelled estimate with ±10 bpm stated, matching its ranking table), SYNTH-43 (short of failure, 'stop when a rep clearly slows'), SYNTH-51 (fasted only on easy days; easy volume because cheap), SYNTH-54 (REF-1087 wording), SYNTH-67 (no high-dose C/E), SYNTH-69 ('timing is a smaller lever' is its title claim; fuel key sessions) and SYNTH-70 (cold water away from lifting; comfort framing).The only conflict is the REF-1090 soreness/CK clause, which SYNTH-70 already corrected on 2026-10-05.