BOB STEWART

Head of Medical at the a Tier 1 International Rugby Team

Team Deployment

Injury Prevention Muscle Priming, Sustained Training, Recovery, Travel, Sleep

Daily use

PROBLEM TO SOLVE

• Camp weeks include one session “tougher than a game” with 48–72 h to be match‑ready; high collision load + speed meters for backs in particular.

• Day‑to‑day pain, stiffness and tendon complaints, especially around high‑force accelerations/decelerations.

• Need a low‑friction recovery system that athletes will wear consistently (beyond standard compression).

KYMIRA INTERVENTION PROTOCOL

Post‑match & post‑session recovery: leggings/socks immediately; sleep overnight in leggings.

Travel: leggings/socks on coach/flight days to reduce stiffness and swelling.

Clinic use: non‑compressive IR for tendon and joint cases (avoid compression‑induced joint swelling); encourage self‑managed joint‑space “carry‑over.”

Optional training use: 5–6 athletes “religiously train in them,” with broader organic adoption in recent tournaments

IMPLEMENTATION NOTES

Recovery rhythm: post‑field (2–4 h) → sleep → travel. Issue 3 outfits/player to maintain compliance during laundry cycles.

• Clinic pathways: for tendon/joint complaints, prefer non‑compressive IR to avoid joint swelling; leverage the hip‑stiffness carry‑over by getting athletes to sleep in leggings.

• Culture lever: start with backs/speed specialists; adoption spreads squad‑wide as athletes feel the difference.

METHODS AT A GLANCE

In‑camp observational tracking across the 2018 Six Nations and subsequent camps: wellness (pain/mobility) and medical notes on soft‑tissue injury incidence.

Context: club → international intensity spike; backs often complete a typical club week’s full‑speed meters in one session at camp

CLINICAL EVIDENCE SUPPORT

The squad‑level reductions in pain (−25%) and stiffness/mobility impairment (−33%) observed across the tournament, together with the group’s ability to sustain higher training intensity, are directionally consistent with controlled studies on far‑infrared (FIR)–emitting textiles that demonstrate locally improved oxygen availability and performance‑relevant recovery effects

In placebo‑controlled trials, FIR garments increased transcutaneous oxygen tension (tcPO₂) by ~5–8% within 30–90 minutes, establishing a plausible pathway for comfort, tissue oxygenation, and readiness between sessions in collision sports that carry a high soft‑tissue load.

Beyond oxygenation, randomized work has also shown objective performance benefits after recovery in FIR—including higher countermovement‑jump metrics and improved neuromuscular status at 24–48 h—supporting the day‑to‑day “bounce‑back” the squad reported. In parallel, laboratory studies with FIR apparel have recorded lower oxygen cost (VO₂) at sub‑maximal intensities for the same external work, a mechanism that can reduce perceived exertion and shorten practica readiness turnarounds when training density is high.

Analgesic and inflammatory pathways provide a second explanatory thread. FIR exposure has been associated with pain modulation and anti‑inflammatory signalling in pre‑clinical and clinical contexts, aligning with the decreases in soreness/stiffness seen at squad level. Finally, a large tcPO₂ RCT and related human datasets (e.g., grip‑strength increases alongside tcPO₂ rises within 90 min) reinforce that the biological effects are measurable under controlled conditions, not solely in field observations.

Selected references: Gordon et al., 2019; Washington et al., 2018; Worobets et al., 2015; Gale et al., 2006; Djuretić et al., 2021; Lever et al., 2025; Bond et al., 2026.