You head off on holiday with a bag already packed with guilt: two weeks without training and it feels like you’re throwing away months of work. Relax. That deload isn’t wasted time — it’s exactly the part of your training where you get stronger. You just have to let it happen.
Rest isn’t the opposite of training
While you’re training, you’re not improving yet: you’re getting tired. Training is only a stimulus that breaks an equilibrium, and the real progress comes afterwards, while you recover and your body rebuilds itself a notch above where it started — what coaches call supercompensation. So without recovery there’s no adaptation: fatigue just piles up without ever turning into fitness.
It’s the principle any serious programme rests on. The consensus statement by Meeusen and colleagues (2013, Medicine & Science in Sports & Exercise) puts it plainly: effective training isn’t just about load, it’s about the balance between load and adequate recovery. When that balance tips too far towards work and not enough towards rest, you don’t get faster — you slide towards overtraining. Seen this way, switching off for the holidays is no betrayal of your plan: it’s part of it.
How much do you really lose in one or two weeks? Less than you think
Let’s start with the numbers, which are more reassuring than the gut feeling. In a study of 15 trained runners, ten days of complete rest changed neither VO2max (the maximum volume of oxygen you can use during effort, the key marker of aerobic fitness) nor heart size (Cullinane et al., 1986, Medicine & Science in Sports & Exercise).
Beyond that, a decline does start to show, but it stays modest — around 6% over the first two weeks — and it’s really after two weeks that it becomes more noticeable. And it’s far more recoverable than you’d imagine. A good part of that early drop isn’t the “engine” shutting down: it’s plasma volume — the liquid part of your blood — falling and then returning within days once you start again (Mujika & Padilla, 2000, Sports Medicine). As for the engine itself, it holds up for a long time: even after three weeks without training, the capillaries and enzymes your muscles use to burn oxygen stayed well above the levels of a sedentary person (Coyle et al., 1984, Journal of Applied Physiology).
The full picture, with the factors that speed up or slow down that decline, is in our article on how quickly you lose fitness after a break. In short: the fitter you are, the more slowly you lose your base — and the faster you get it back.
Active recovery or complete rest?
There are two ways to switch off, and they suit different situations.
- Active recovery — moving lightly without training: a walk, a swim, a hike, an easy conversational-pace bike ride. It keeps your blood volume, your mood and the habit of movement going without adding any stress, and it’s the right choice in most cases. That’s exactly why a holiday is never a real “stop”: between the beach, the trails and swims, you keep moving anyway, and that little is enough to preserve most of what you’ve built.
- Complete rest — no structured activity at all. It makes sense when you reach your holiday truly drained, or carrying a small niggle that just needs to be left alone.
The rule is simple: if the urge to move is there, move easy; if the very idea of any effort puts you off, give yourself a few days of full rest, because that reluctance is information, not laziness.
If you want concrete ideas, we’ve put together 6 tips for training on holiday and a 20-minute bodyweight strength circuit you can do anywhere, with no equipment.
Use your holiday as a planned deload week
In a well-built plan, deload weeks aren’t accidents: they’re scheduled at regular intervals, with less volume, to give the body time to absorb the work and supercompensate. That’s also the logic behind 2PEAK, which is built on periodisation: the structured alternation of load phases and recovery phases. Every cycle ends with a transition phase (phase 4), a low-load, less structured regeneration period — and that’s exactly where your holiday belongs. If you reach the summer tired, after a demanding block or a race, the timing is perfect: you’ll come back not just rested but often a notch above, because what you sowed in the hard weeks blooms while you’re resting.
The signs you needed to switch off
Sometimes the holiday doesn’t fall by chance: it comes just when your body was already asking for it. The signs of accumulated fatigue are fairly recognisable, and the overtraining literature describes them well (Meeusen et al., 2013): a tiredness that sleep doesn’t repay, flagging motivation, a shorter temper than usual, disturbed sleep, performances that stall or slip even though you keep training. If two or three of these ring true, the break isn’t a luxury but genuine treatment, and stubbornly pushing on would be the quickest way to tip into an overtraining state that takes weeks, sometimes months, to climb out of. Two weeks under a parasol now are well worth it.
Enjoy your holiday
So set off with a clear mind. Move the little you feel like — a walk, a swim, nothing structured if you don’t fancy it — and stop counting what you’re “losing”; think instead about what you’re rebuilding. You’ll come back with a clear head and fresh legs, and that’s where you set off strong again. And on your return you’ll have no backlog to catch up on: 2PEAK recalibrates your plan to your real current form, adjusting it after every session, so you pick up exactly where you actually are — not where a rigid schedule assumed you should be.
Sources
Cullinane EM, Sady SP, Vadeboncoeur L, Burke M, Thompson PD (1986). Cardiac size and VO2max do not decrease after short-term exercise cessation. Medicine & Science in Sports & Exercise, 18(4), 420–424.
Coyle EF, Martin WH 3rd, Sinacore DR, Joyner MJ, Hagberg JM, Holloszy JO (1984). Time course of loss of adaptations after stopping prolonged intense endurance training. Journal of Applied Physiology, 57(6), 1857–1864.
Mujika I, Padilla S (2000). Detraining: loss of training-induced physiological and performance adaptations. Part I. Sports Medicine, 30(2), 79–87.
Meeusen R, Duclos M, Foster C, et al. (2013). Prevention, diagnosis and treatment of the overtraining syndrome: joint consensus statement of the ECSS and ACSM. Medicine & Science in Sports & Exercise, 45(1), 186–205.
