Ketones, Red Light and Hot Tubs: What Three New Recovery Trials Found

Before you add another recovery tool, ask one question: what did it beat? Three new 2026 trials tested popular recovery add-ons against a placebo, a sham treatment, or a direct comparison. None showed a clear edge. Here is what each found, how small the studies were, and a two-week test you can run on your own routine.

Ketone drinks: no clear recovery benefit

In a double-blind trial, 18 well-trained cyclists completed a simulated 8-day stage race. After each stage and 30 minutes before sleep, 8 riders took 25 g of a ketone ester and 10 took a taste-matched placebo. Both groups got more tired as the race went on: peak heart rate fell by about 11 beats per minute and 30-minute time trial performance dropped about 3%. The authors found no clear benefit of the ketone ester on recovery, sleep, cognitive function, or endurance performance. In the ketone group only, mechanical efficiency at 200 W got worse and fat oxidation rose 120%.^[1]

The limit: with 18 riders, a trial can miss a modest effect. It also tells you nothing about people who lift, walk, or train for a few hours a week.

Red light therapy: no change in muscle mitochondria after one session

Photobiomodulation (low-level laser or LED light) is sold on the idea that red and infrared light boosts mitochondria, the energy-producing parts of your cells. To test it in people, researchers gave 12 healthy adults (average age 25) three cycles of about 5 minutes of light on one randomly chosen leg and a sham treatment, with the light off, on the other. Skin on the treated leg warmed by 8.0 °C, so the device did something. But maximal mitochondrial respiration did not differ between legs, in skin or in muscle (muscle: 474 vs 467 pmol/sec/mg dry weight, P=0.71). Of 91 muscle genes measured, only 3 differed in expression.^[2]

The limit: this was one session, measured right afterward, in young healthy volunteers. It tested a cell-level claim, not soreness, joint pain, or performance, and it does not cover every device or dose.

Cold bath vs. hot bath: same result

Twenty-two active men played a simulated football match, then sat in either cold or hot water right afterward and again at 24 and 48 hours. The match cost them about 7.0% of maximal quadriceps strength, 8.9% of sprint power at 24 hours, and left them sore at 24 and 48 hours. Across 72 hours, cold and hot immersion did not differ on any measure. ^[3]

The authors read this as hot-water immersion being a practical alternative to cold. There is a second reading: the study compared two treatments and had no group that skipped immersion, so it cannot show that either one beat simply waiting. If you like a warm bath or a cold plunge, the study gives you no reason to feel bad about it. It also gives you no proof that the water did the recovering. If you have heart disease or high blood pressure, check with your clinician before deliberate hot or cold immersion.

A two-week test for any recovery add-on

1. Lock in the basics first: a steady sleep window, protein at your meals, and an easy day after a hard one.
2. Change one thing at a time and run it for two weeks.
3. Log two numbers: next-morning soreness from 0 to 10, and one repeatable performance marker, such as reps at a set weight or your time on a regular route.
4. Compare against the two weeks before. If both numbers are unchanged, drop it. If soreness improves and performance stays flat, you have a comfort tool, which is a fair reason to keep it. Just call it that.
5. Ask what the claim was tested against. A placebo or sham group is what lets a result mean something.

A self-test like this cannot rule out placebo effects. It can tell you whether something is worth your time and effort.

What these trials do and do not show

• All three were small: 8 and 10 per group, 12 people, and 22 people.
• The abstracts do not report results specific to people over 40.
• A study that finds no difference does not prove an effect is zero. It sets a ceiling on how big the effect is likely to be in that group.
• Each tested one dose and one timing. Different protocols could behave differently.

References

[1] Engelbrecht L, Lauriks T, Robberechts R, Stalmans M, et al. Ketone ester intake did not improve performance, neither cognitive function or sleep, during an 8-day simulated cycling race. Med Sci Sports Exerc. 2026. Finding as used: 18 well-trained cyclists, 25 g ketone ester (n = 8) vs placebo (n = 10); no clear benefit on recovery, sleep, cognitive function, or endurance performance; peak heart rate fell ~11 bpm and time trial performance ~3% in both groups; in the ketone group only, impaired mechanical efficiency at 200 W and 120% higher fat oxidation. https://doi.org/10.1249/mss.0000000000004119 ↑︎

[2] Aussieker T, Petrick HL, Kuin R, Kaiser J, et al. Photobiomodulation does not increase mitochondrial respiration in skeletal muscle or skin tissue in humans. Med Sci Sports Exerc. 2026. Finding as used: 12 healthy adults, within-participant sham-controlled; skin temperature +8.0 ± 1.4 °C on treated leg only; no difference in maximal respiration in skin or muscle (474 vs 467 pmol/sec/mg dry weight, P=0.71); 3 of 91 genes differed. https://doi.org/10.1249/mss.0000000000004120 ↑︎

[3] Bandiera D, Di Domenico H, Samozino P, Racinais S, Rupp T. No differences between cold and hot water immersion for neuromuscular recovery, sprint mechanics and delayed onset muscle soreness after a simulated football game. J Sports Sci. 2026. Finding as used: 22 active males; 7.0% drop in maximal voluntary contraction, 8.9% loss of sprint power at 24 h, soreness up at 24 and 48 h; no significant differences between cold and hot immersion during 72 h of recovery. https://doi.org/10.1080/02640414.2026.2713869 ↑︎

Kurt Greiner

Kurt is a digital strategist and IT professional blending emerging technology with practical application, exploring how individuals can leverage modern tools to navigate the second half of life with purpose.