Dr. Gymbro
A softly lit editorial still life on a pale oat-colored linen surface, shot from a slightly elevated three-quarter angle in a wide landscape composition. At center-left, a small matte amber glass jar sits open, with a scattering of fine cream-colored powder dusted across the linen and a few off-white capsules spilling out in a loose, natural arc. A minimalist wooden scoop rests beside the jar. To the right, a clean sheet of cream paper holds a hand-drawn line graph in thin charcoal ink. Two lines run nearly parallel and drift slightly apart, with a faint dotted horizontal threshold line they never cross. A sharpened pencil lies across the corner of the paper. In the soft-focus background, a ceramic cup of black coffee, a folded sage-green cotton napkin, and a sprig of dried eucalyptus add quiet texture. Morning window light enters from the left, casting long, gentle shadows and a warm highlight along the glass jar's rim. The palette is restrained and modern: warm beige, muted sage, soft terracotta, charcoal, and touches of amber. Shallow depth of field keeps the jar and graph crisp while the edges melt into creamy blur. Generous negative space on the upper right leaves room for headline overlay. The mood is calm, thoughtful, and skeptical, with the clean, tactile look of a contemporary wellness and science journal. No people, no text, no logos, no futuristic elements.
Science & Research

Turkesterol konačno testiran na IGF‑1 kod muškaraca – rezultati nisu ono što su influenseri obećali

Coach Ryan · · 3 min read

Studija u jednoj rečenici

Mala ekipa sa Univerziteta Baylor podala je jedanaest mladim muškarcima turkesterol i nije otkrila statistički značajan efekat na IGF‑1, bazalni metabolički ritam (RMR) niti na metabolizam masti i ugljenih hidrata. Brojevi su se pomerili u smeru koji bi marketari suplemenata želeli, ali nisu prešli prag značajnosti.

Turkesterol je biljni sterol koji se na društvenim mrežama promoviše kao „prirodni steroid“ koji podstiče mišićni rast, a ne nosi neželjene posledice anaboličkih androgenih steroida (AAS). Uprkos tome, o njegovom učinku na ljudima postoji vrlo malo podataka. Ovaj rad, objavljen u Muscles 2024. godine, jedan je od prvih pokušaja da se hype testira na stvarnim ljudima.

Šta su istraživači zaista uradili

Studija je bila placebo‑kontrolisana preliminarna istraga. Jedanaest navodno zdravih muškaraca (prosečna starost 23,3 ± 2,2 godine) dobrovoljno se prijavilo. Učesnici su primali turkesterol u više akuta doza, uz poređenje sa placebom. Uzorci su prikupljeni u tri tačke:

  • Pre unosa (bazna vrednost)
  • 3 sata posle unosa
  • 24 sata posle unosa

Glavni ishodi su bili serumski IGF‑1 – hormon povezan sa sintezom mišićnih proteina i signalizacijom rasta – i bazalni metabolički ritam (RMR), koji se koristio da se testira tvrdnja da turkesterol pojačava termogenezu. Pratili su se i markeri lipidnog i ugljeničnog metabolizma. Apstrakt ne navodi tačne doze u miligramima, pa ni ovaj tekst ne pruža te podatke.

Naslovni rezultat: ništa značajno

Statistička analiza nije otkrila značajan glavni efekat uslova, vremena ili njihove interakcije za serumski IGF‑1, RMR, lipidni metabolizam ili metabolizam ugljenih hidrata (sve p > 0,05). Jednostavno rečeno, istraživači nisu uspeli da razaznose bilo kakav efekat turkesterona u odnosu na placebo ili na normalne fluktuacije tokom vremena.

To je zaključak. Sve ostalo je sporedno.

„Trend“ koji bi svi željeli da citiraju

Autori su primetili dva ne‑značajna obrasca:

  1. IGF‑1 je porastao pod oba uslova (turkesterol i placebo) i ostao viši u odnosu na početnu vrednost.
  2. RMR je bio iznad bazne vrednosti u 3‑satašnjem merenju.

Ne‑značajan trend ne predstavlja skriveni pozitivan rezultat. Sa samo 11 učesnika, studija ima ograničenu snagu da otkrije skromne efekte, pa ovi obrasci mogu biti pravi signal koji bi veća studija potvrdila – ili jednostavno slučajni šum. Dizajn studije ne može da razgradi razliku, a autori to jasno ističu, opisujući svoje podatke kao ne‑potpun dokaz da je turkesterol „moćan anabolički suplement“.

Zašto ova studija ne može da reši pitanje

Pre nego što odlučite da bazirate svoje treninge ili suplementaciju na ovom istraživanju, imajte u vidu sledeća ograničenja:

  • Mali uzorak. Jedanaest mladih, zdravih muškaraca je pilot‑grupa; rezultati ne moraju važiti za žene, starije osobe ili napredne vežbače.
  • Samo akutno doziranje. Posmatrani su efekti u okviru nekoliko sati i jednog dana, a ne tokom nedelja suplementacije uz trening.
  • Indirektni pokazatelji. IGF‑1 je samo proxy. Nisu merene veličina mišića, snaga niti sinteza mišićnih proteina, pa se ne može izvući zaključak o hipertrofiji.
  • Nedostatak treninga. Pravi mišićni rast zahteva otporni trening, adekvatan unos proteina i vreme. Ništa od toga nije bilo deo protokola.

Autori eksplicitno pozivaju na buduća istraživanja koja bi procenila dugoročne promene IGF‑1 i mišićnog rasta pod turkesterolom kroz višenedeljne trening sesije.

Dobra vest: tolerancija

Istraživači su istakli povoljan profil hemodinamičke i gastrointestinalne tolerancije. Na testiranim dozama, tokom kratkog perioda, turkesterol nije izazvao značajne kardiovaskularne ili gastrointestinalne probleme kod učesnika. To je korisno, ali predstavlja kratkoročni sigurnosni signal u jedanaest osoba, ne dokaz dugoročne bezbednosti.

Šta to znači za vas

Da li izgrađuje mišiće? Još uvek nema dokaza. Studija nije merila mišićni rast, a hormonski i metabolički ishodi nisu bili statistički različiti od placeba.

Doziranje: Ne postoji dokazano zasnovana doza za rast mišića. Apstrakt ne navodi doze, pa ništa ovde ne potvrđuje etiketu proizvoda ili protokol influensera.

Vremenski raspored: Merenja su obavljena u 3 i 24 sata posle unosa, pa podaci ne pružaju osnovu za strategiju „pre treninga“ ili „uz obrok“.

Ko bi to mogao koristiti? Zainteresovani, zdravi odrasli koji su spremni da prihvate da je potencijalni benefit neproveren i da čekaju bolje podatke. Trošenje novca na ovaj suplement ne bi trebalo da zameni osnovu: progresivan otporni trening, adekvatan unos proteina, san i ukupni kalorijski balans.

  • Osobe koje očekuju rezultate slične onima kod steroida. Ništa u ovoj studiji ne podržava takvu paralelu.
  • Ljudi sa hormonski osetljivim stanjima ili koji uzimaju lekove, a nisu se konsultovali sa lekarom.
  • Trudnice, dojilje i sve osobe mlađe od 18 godina.
  • Takmičarski sportisti podložni testiranju, koji bi trebalo da provere pravila svojih sportskih tela i sastav bilo kojeg proizvoda pre upotrebe.

Zaključak

Prvi ljudski podaci o turkesteronu i IGF‑1 ne pokazuju značajan efekat. Pokazuju trend koji bi mogao biti stvaran, ali je uzorak premali i period prekratak da bi se to potvrdilo. Dok duže studije ne mere stvarni mišićni rast, tretirajte turkesterol kao neproveren suplement, a ne kao prirodan prečac ka rezultatima na nivou steroida.

Original study

Read the original research on pubmed.ncbi.nlm.nih.gov →

This article summarizes published research for general information. It is not medical advice.

CR

Written by

Coach Ryan

Coach Ryan writes for Dr. Gymbro: science-backed fitness, nutrition & performance.

Related Articles

A wide, editorial-style flat lay photographed from above on a pale warm-gray linen surface in soft natural window light. At the center, a small open amber glass jar tips gently onto its side, spilling a few cream-colored capsules across the fabric. Next to the jar sits a loose arrangement of fresh mushrooms: a cluster of golden-tan reishi with glossy, lacquered caps, a few slender white enoki stems, a halved shiitake showing its pale gills, and a curl of turkey tail with concentric bands of rust, cream, and charcoal. A small wooden scoop holds a pile of fine beige mushroom powder.

On the left third of the frame, a matte black sports watch with a minimal face lies beside a folded sage-green running shirt and a pair of lightweight off-white running shoes, hinting at athletic training without showing a person. A slim white notebook with a single pencil rests nearby, open to a blank page with a faint hand-drawn line graph trending upward, in thin graphite strokes.

On the right side, a pair of clear glass beakers and a single small petri dish with a soft amber-tinted liquid add a subtle laboratory note, kept calm and organic. A single sprig of dried herbs and a few scattered oat-colored grains add texture.

The palette is earthy and refined: oatmeal, soft sage, terracotta, warm amber, and charcoal accents against the muted neutral background. Shadows are soft and diffused, with a gentle highlight on the glass and the glossy reishi cap. The composition leaves generous negative space in the upper right for a headline overlay. Shallow depth of field blurs the edges slightly, while the central mushrooms and capsules stay crisp. The overall feel is modern, clean, and trendy, like a wellness and science magazine cover, with tactile natural textures, minimal styling, and a quiet sense of curiosity and skepticism.
science research

Kapsula od pečuraka podigla VO2max za 14,8 % — ali postoji velika zamka

BY DR. GYMBRO ·

Kapsula od pečuraka, 40 dana i rast VO2max‑a od 14,8 % zvuče gotovo previše dobro da bi bilo istinito. U novom radu u časopisu *Antioxidants* 50 mladih sportista je uzimalo 320 mg dnevno ekstrakta bogatog beta‑glukanom i njihova maksimalna potrošnja kiseonika porasla je sa 46,26 na 53,12 mL/kg/min. Velika zamka je što studija nema kontrolnu (placebo) grupu, nije randomizovana i nije slep.

A wide, editorial-style flat lay photographed from above on a pale warm-gray concrete surface, lit by soft natural window light with gentle shadows. On the left, three small matte ceramic bowls in sage green, soft terracotta, and cream, each holding a different white crystalline powder. The textures vary subtly: fine and powdery, slightly granular, and glittery with tiny crystalline flecks. Beside them rest three minimalist wooden scoops, a few scattered grains catching the light. In the center-right, a worn classic black-and-white soccer ball sits slightly off-frame, partially cropped by the edge, with a pair of muted navy cleats resting nearby, laces loosely draped. A small stopwatch with a brushed-steel finish and a folded sheet of graph paper with a hand-drawn bar chart in soft coral and teal pencil add a subtle sense of data and measurement. A few blades of fresh-cut grass and a sprig of eucalyptus add organic accents. The palette is calm and modern: warm neutrals, sage, terracotta, and muted navy, with one pop of coral. The composition leaves generous negative space in the upper right for headline text. The mood is clean, curious, and trustworthy, like a contemporary health and science journal. Shallow depth of field, crisp focus on the powders, with the soccer elements slightly softer. High-end editorial photography, 16:9 landscape.
science research

Kreatin HCl pobedio monohidrat kod fudbalskih igrača — ne bacajte svoj još

BY DR. GYMBRO ·

Randomizovani eksperiment na 40 fudbalskih igrača pokazao je da su kreatin HCl i etil‑ester nadmašili obični monohidrat po skoku, sprintu, agilnosti i maksimalnoj snazi već nakon četiri nedelje. Svaka forma kreatina bila je bolja od placeba, ali „fensi“ verzije dodatno su pojačale eksplozivne performanse. Ipak, u studiji je po 10 sportista po grupi, doze nisu navedene, a rezultati su u suprotnosti s prethodnim istraživanjima. Ovde je objašnjeno šta je otkriveno, šta nije i kako to da protumačite.

A wide, editorial-style still life shot from a slightly elevated angle on a pale oatmeal-colored linen surface in soft, diffused morning light. At the center, a shallow matte ceramic bowl in warm terracotta holds a small mound of fine, golden-tan ashwagandha root powder. Beside it lie a few gnarled, dried ashwagandha roots and a sprig of green leaves with tiny orange-red berries in their papery husks. To the left, a minimalist amber glass supplement bottle sits with a few capsules spilled beside it, label blank and clean. A wooden scoop rests on the surface, dusted with powder.

On the right side of the frame, a pair of sleek, muted sage-green running shoes sits slightly off-center. A folded cream towel and a stainless steel water bottle sit just behind them, with a single brushed-steel kettlebell partly out of focus in the background to hint at strength training without dominating the scene. The running shoes and the botanical elements share equal visual weight, suggesting the endurance theme.

A thin, curved line of scattered powder sweeps across the linen from the bowl toward the shoes, like a gentle path or track. Soft shadows fall to the left, and a warm sunbeam crosses the surface and picks out the texture of the powder and the roots.

The palette is restrained and modern: warm terracotta, sage green, cream, soft gold, and touches of charcoal. The background is a blurred pale plaster wall with a hint of a window shadow. Shallow depth of field, crisp focus on the bowl and roots, and generous negative space in the upper left for a headline. Contemporary wellness magazine aesthetic, calm, natural, tactile, high-end lifestyle photography, no text, no people, no futuristic elements.
science research

Iznenađenje Ashwagandhe: Pomaže izdržljivost više nego snagu

BY DR. GYMBRO ·

Ashwagandha se često reklamira kao dodatak za izgradnju mišića, ali nova meta‑analiza pokazuje da je najkonzistentniji efekat – poboljšanje aerobne izdržljivosti. Istraživanje je obuhvatilo 13 randomizovanih studija sa ukupno 599 učesnika, pri čemu je najjači beneficij primećen uz dozu od 500‑600 mg ekstrakta dnevno. Međutim, predikcioni interval uključuje nulu, pa efekat nije garantovan u svim uslovima. U ovom tekstu saznajte ko može imati najviše koristi od suplementa i ko bi ga trebao izbegavati.

Wide landscape editorial photograph of a mountain biker mid-ride on a dusty red-orange singletrack trail in the South African Western Cape, golden hour light raking across the scene. The rider is in sharp focus on the right third of the frame, wearing a weathered cycling kit with a race number plate on the handlebars, dust kicking up from the rear tire. Behind them, rolling hills covered in fynbos shrubland and silhouetted protea plants fade into soft, hazy blue mountains. Warm amber sunlight creates long shadows and a soft rim light around the rider and bike.

In the lower left foreground, slightly out of focus, a small minimalist glass vial and a clear water bottle sit on a flat sun-bleached rock, with a few drops of liquid catching the light. Next to them, a simple matte paper notecard and a pencil suggest data collection, with no legible text. The vial and bottle are clean, understated, and modern, with no branding.

The color palette is earthy and refined: terracotta, ochre, sage green, dusty teal sky, and cream highlights. The composition uses shallow depth of field, a generous negative space in the upper left sky for headline overlay, and subtle film grain. The mood is contemplative, skeptical, and quietly sophisticated, like a feature photograph from a high-end outdoor sports and science magazine. Natural, candid, cinematic, shot on a 50mm lens with soft contrast and muted saturation. No futuristic elements, no glowing effects, no molecular graphics, no text.
science research

Ketone IQ je podigao nivo ketona na Cape Epicu, ali nije postigao nikakve druge učinke

BY DR. GYMBRO ·

Vozači na osmodnevnom Cape Epicu pili su Ketone IQ dva puta dnevno i postigli oko 1 mM ketona u krvi, ali njihov umor, puls, vreme reakcije i oporavak bili su isti kao kod vozača koji su uzimali placebo. Duplo slepa studija testirala je R‑1,3‑butandiol u stvarnim trkačkim uslovima, a ne u laboratoriji. Autori navode da blaga ketoza nije bila efikasna i da se butandiol ne sme mešati sa ketonskim esterima. Sa samo 18 učesnika, studija ima značajna ograničenja, ali predstavlja važnu informaciju za sve koji razmišljaju o skupom ketonskom napitku za oporavak.

This page is available in