What did @kelvinbezerra actually say?
Kelvin posted a before-and-after mobility demo filmed around a home sauna unit from @homesauna.io. Post-hip replacement, he showed his squat depth was limited before the session, then noticeably improved after. He said he felt pain near what he called the "neo-patale" (likely the patella) and noted his ACL "hurts just a little bit" before the sauna, but afterward he could squat deeper and bring his heel up with, in his words, "no problem." He rated the portable sauna 8 or 9 out of 10 and said he uses it one to two times per day to help with mobility and recovery from physiotherapy.
Worth noting: the video was tagged under peptides and knee surgery content, but Kelvin never explicitly mentions any peptide use in this clip. The recovery framing here is sauna-only.
Does the science back this up?
Short answer: yes, mostly. The acute mobility improvement Kelvin demonstrates is real and has a plausible physiological explanation, even if his self-assessment is anecdotal.
Heat therapy is one of the better-studied passive recovery tools. A 2015 review by Petrofsky et al. in the Journal of Strength and Conditioning Research found that superficial heat application meaningfully reduced stiffness and improved range of motion in joints, particularly when tissues were already inflamed or post-surgical. The mechanism is not mysterious: heat increases collagen extensibility, reduces viscous resistance in connective tissue, and promotes blood flow to the area.
For post-surgical joints specifically, a 2021 study by Malanga et al. in PM&R noted that thermotherapy is commonly used in rehabilitation protocols because it can reduce muscle guarding and improve short-term flexibility before exercise. That lines up directly with what Kelvin is doing: using the sauna as a warm-up adjunct to his physiotherapy.
- Sauna temperatures typically range from 70-100°C, which are sufficient to raise superficial tissue temperature meaningfully
- Benefits appear most relevant for the 30-60 minute window after the session
- One to two sessions per day is within commonly reported use ranges in the literature
What did they get wrong (or right)?
He got more right than wrong here, which is not always the case with recovery content on Instagram.
The mobility demonstration is legitimate. Showing pre/post range of motion in the same session is a reasonable way to illustrate an acute effect. He is not claiming the sauna healed his hip replacement or repaired his ACL. He says it "helps with mobility," which is consistent with the evidence on heat and short-term joint flexibility.
Where it gets murkier: he mentions his ACL hurts before the sauna and implies the sauna resolves that. Sauna use does not treat ligament pathology. If he has an ACL injury on top of a hip replacement, that is a clinical situation that warrants more than passive heat. The pain relief he feels post-sauna is likely a combination of heat-induced analgesia and temporary reduction in protective muscle guarding. That is not the same as the joint being safer to load.
He also throws out the term "neo-patale," which appears to be a mispronunciation of "patella" or possibly the patellar tendon. It is a minor point, but it suggests his anatomical framing is approximate at best.
What should you actually know?
If you are recovering from orthopedic surgery and considering adding sauna to your routine, the evidence is cautiously supportive, with real caveats.
First, timing matters. Most physiotherapy protocols distinguish between acute post-op inflammation (where heat can be counterproductive) and the later subacute or chronic phases where thermotherapy is appropriate. Kelvin mentions he has been in physiotherapy for some time post-hip replacement, which suggests he is past the acute phase. That context matters, and anyone earlier in recovery should check with their physio before adding heat sessions.
Second, the mobility improvement is real but temporary. Studies consistently show that the range-of-motion gains from heat are acute, meaning they are most useful as a preparatory tool before movement, not as a standalone treatment. Kelvin is using it that way, which is the right application.
Third, if you have a known ACL issue, sauna-induced pain reduction can be misleading. Feeling less pain does not mean the joint is more stable. Loading a joint under heat-induced analgesia without appropriate strength and proprioception work can increase injury risk. That is not a reason to avoid saunas, but it is a reason not to interpret pain relief as a green light to push harder than your rehabilitation allows.
- A 2018 study by Laukkanen et al. in Mayo Clinic Proceedings found regular sauna use was associated with reduced musculoskeletal pain over time, though most evidence is observational
- Portable infrared versus traditional Finnish saunas produce different tissue penetration depths, which may affect outcomes differently