Posted by Smart Strips
on October 20, 2026
Last updated: 19 October 2026
If your muscles hurt more two days after a workout than the day after, that is normal: delayed onset muscle soreness (DOMS) typically peaks 48 to 72 hours after a hard or unfamiliar session (Hotfiel et al., 2018). It eases over several days, and the most useful things you can do are sleep well, eat enough protein and keep day two light.
Monday evening you went back to the gym after the summer: squats, lunges, a few sets on the leg press. You felt fine walking out. Tuesday was a little stiff. On Wednesday morning the stairs down to the kitchen feel like a negotiation.
This guide explains why soreness arrives late, how to plan the days while it peaks, and where a post-training oral dissolvable strip such as Smart Strips Refuel fits into the two days after a session.
Why do my muscles hurt two days after a workout?
The name for it is delayed onset muscle soreness, or DOMS. A review of its causes describes the symptoms as typically delayed, with peak soreness at 48 to 72 hours after exercise (Hotfiel et al., 2018). The soreness you feel on day two is a response to small-scale strain in muscle that was asked to do more, or something different, than it is used to.
Researchers who study it usually provoke it on purpose with eccentric exercise, the lowering phase of a movement, where the muscle lengthens under load. That is why walking downhill, lowering a heavy weight slowly or returning to squats after a break tends to leave the strongest memory.
How long does muscle soreness last?
For most people it eases over several days. What matters more in practice is the window when it is strongest. If you train on Monday, Wednesday is the day to expect it, and planning the week around that helps: a lighter session, a walk, or training a different muscle group on day two or three.
Should you train when your muscles are sore?
Usually yes, but lighter. Walk, stretch gently or train a different muscle group, and save the hardest session for when the soreness has passed its peak. Two habits make the biggest difference to how those days feel.
Sleep. The American Academy of Sleep Medicine and the Sleep Research Society recommend that adults "should sleep 7 or more hours per night on a regular basis to promote optimal health" (Watson et al., 2015). Recovery happens on the nights after training, so a short night before a hard session and another after it is a poor combination. If you wake at 4am with a busy mind, our guide on why you wake up at 4am covers that second half of the night.
Protein, spread through the day. The International Society of Sports Nutrition states that 1.4 to 2.0 g of protein per kilogram of body weight per day is sufficient for most exercising individuals, and that doses are best spread every 3 to 4 hours (Jäger et al., 2017). Many people who train after work eat most of it at dinner and very little at breakfast. Moving some of it to the morning is often the easiest change.
For the full routine after a session, with protein, water and sleep in detail, see our guide to recovery after a workout.
Where does Refuel fit in?
Think about the ten minutes after training. Shower, bag, keys, the drive home, already thinking about dinner and tomorrow's meetings. Recovery is the part of training that gets planned least. Refuel was made for that moment: one oral dissolvable strip on the tongue after the session, while you are still in the changing room.
It melts in 7 to 30 seconds, without water. It is vegan, free of sugar and gluten, sweetened with stevia, with a ginger and lime flavour.
What is in each strip
| Ingredient | Per strip |
|---|---|
| Liposomal curcumin | 40 mg |
| Palmitoylethanolamide (PEA) | 20 mg |
| NAD+ | 10 mg |
Liposomal curcumin. Curcumin is the main active compound of turmeric; the liposomal form wraps it in tiny lipid spheres. The amount in one strip sits well within EFSA's acceptable daily intake for curcumin of 3 mg per kilogram of body weight (EFSA, 2010).
Palmitoylethanolamide (PEA). A fatty acid amide the body makes itself.
NAD+. A coenzyme that "acts as a cofactor in multiple reduction-oxidation (redox) reactions related to energy production" (Navas and Carnero, 2021).
The purpose of Refuel is to give recovery a fixed place in the routine, next to the habits that do the heavy lifting: sleep and protein. Once there is a small post-training step, the rest of the routine (water, a proper meal, an earlier night) tends to follow. Athletech News, the US fitness business publication, has featured Smart Strips.
Why an oral dissolvable strip after training?
Part of each strip's dose is absorbed through the lining of the mouth, in places only 100 to 200 µm thick (Hua, 2019), and the rest is swallowed with saliva. Compared with a swallowed tablet, the Smart Strips format stands on three figures: up to 95% bioavailability, up to 4x faster and up to 30% more effective. The strips are made with QuickRelease™ technology (patent pending). More on the format in What are oral dissolvable strips.
The practical reason is simpler. After training, few people want to mix another drink or swallow capsules in a car park. The sachet is light and lives in the gym bag.
What does a 48-hour plan look like?
Right after the session. One Refuel strip in the changing room. Water. If the next meal is more than a couple of hours away, something with protein: yoghurt, a sandwich with eggs or cheese, a glass of milk.
The evening. A proper dinner with a protein source. Screens away a little earlier than usual. If you train late and sleep lightly, our Z-z-Zen strip is made for the night, one strip 20 to 30 minutes before sleep.
Day two. Expect the stiffness to rise rather than fall. Walk, stretch gently, train a different area or rest. This is the day people often decide they are "not made for the gym". They are; the timeline is normal.
Day three. Soreness is usually past its peak. A good day to train again, ideally with an energy routine you can plan around. Our guide to pre-workout without the crash explains how FCKN Fit before training and Refuel after it work as a pair, and the Fitness Ready set puts both in one box.
Who should not take Refuel?
Refuel is for adults. Follow the daily intake on the box. Consult your doctor if you are pregnant, nursing, taking medication (particularly blood thinners) or have a medical condition, including any liver or gallbladder condition. Food supplements are not a substitute for a varied, balanced diet and a healthy lifestyle.
Sources
- Hotfiel T, Freiwald J, Hoppe MW et al. Advances in Delayed-Onset Muscle Soreness (DOMS): Part I: Pathogenesis and Diagnostics. Sportverletz Sportschaden. 2018;32(4):243-250. DOI 10.1055/a-0753-1884
- Watson NF, Badr MS, Belenky G et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the AASM and SRS. J Clin Sleep Med. 2015;11(6):591-592. DOI 10.5664/jcsm.4758
- Jäger R, Kerksick CM, Campbell BI et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. DOI 10.1186/s12970-017-0177-8
- EFSA ANS Panel. Scientific Opinion on the re-evaluation of curcumin (E 100) as a food additive. EFSA Journal. 2010;8(9):1679. DOI 10.2903/j.efsa.2010.1679
- Navas LE, Carnero A. NAD+ metabolism, stemness, the immune response, and cancer. Signal Transduct Target Ther. 2021;6:2. DOI 10.1038/s41392-020-00354-w
- Hua S. Advances in nanoparticulate drug delivery approaches for sublingual and buccal administration. Front Pharmacol. 2019;10:1328. DOI 10.3389/fphar.2019.01328
