Training when you're sick, travelling or short on sleep

Every training plan meets the same three obstacles sooner or later: you get ill, you travel, or you sleep badly for a while. None of them means your fitness is slipping away. Each one does call for a slightly different response, and knowing which is which saves you from both overdoing it and stopping for longer than you need to.

Training when you're ill

A common rule of thumb among coaches is the "neck check". If your symptoms are only above the neck, such as a runny nose, a mild sore throat or a blocked head, light exercise is often fine. If symptoms are below the neck, such as a chesty cough, body aches, an upset stomach or a fever, rest.

It's a useful starting point, not a medical test. A few points make it safer:

• Fever means rest. Don't train with a raised temperature, even if the rest of you feels fine. Your body is already working hard.
• Lower the dose, not just the pace. If you do train with a head cold, make it short and easy. A 20-minute walk or gentle spin is plenty.
• Stop if you feel worse. If symptoms build during the session, end it. Feeling slightly better afterwards is a good sign. Feeling worse means the body wanted rest.

The International Olympic Committee's consensus statement on load and illness lists rapid changes in load, travel, poor sleep and psychological stress among the things that raise illness risk in athletes. It also notes that performance can stay lower for a short while after you feel recovered. So the end of symptoms isn't the moment to test yourself.

Coming back after illness

The return matters more than the time off. A few days of rest costs very little fitness. A rushed comeback that turns into a relapse costs much more.

A sensible pattern is:

1. Wait for a normal day. Get through at least one full day of feeling normal, without medication masking symptoms, before training again.
2. Start with easy sessions. Your first one or two sessions back should be short and comfortable, about half the usual duration and at an effort where you could hold a conversation.
3. Rebuild over days, not in one go. If the easy sessions feel fine, add duration first, then intensity.
4. Skip the catch-up. The sessions you missed while ill are gone. Doubling up after illness stacks a load spike on a body that's still recovering. There's more on why in how an adaptive plan handles missed sessions.

Training while travelling

Travel creates two separate problems: disrupted routine and, across time zones, a body clock that's out of step with local time.

The CDC's travel guidance says the body clock adjusts by about one hour a day after flying east and about an hour and a half a day after flying west. A six-hour shift eastward can take most of a week to settle. The same guidance recommends getting daylight at the right times for your direction of travel, keeping naps to about 20 to 30 minutes, and stopping caffeine about six hours before bed.

For training, that suggests a few practical rules:

• Keep sessions short and easy for the first days. Intervals and heavy lifts at 3 am body time are rarely good sessions.
• Use exercise to anchor the new day. An easy run or walk outdoors in local daylight gives you light and movement at once.
• Pack a hotel-room session. Bodyweight squats, lunges, push-ups, planks and a resistance band cover a lot in 20 minutes.
• Protect sleep over volume. If the choice is an early session or an extra hour of sleep after a long flight, the sleep usually wins.

If your trip takes you somewhere hilly, it can be a good chance to explore. The approach in walk the climbs works well for unfamiliar terrain: run by effort, not pace, and walk the steep parts.

Training when you're short on sleep

The CDC recommends that adults aged 18 to 60 get seven or more hours of sleep a night. Plenty of weeks fall short of that, so the question is what to do about it.

One short night rarely changes much. You might feel flat, but your capacity to train is mostly intact. Keep the session, perhaps trim the hardest part, and get to bed earlier.

Several short nights in a row are different. The effect builds, and hard sessions start to feel harder than they should. A few adjustments help:

• Swap intensity for easy volume. An easy run or a lighter strength session still counts.
• Keep the week's key session if you can. Move the quality work to the day after your best night.
• Look at the trend, not one number. Sleep, resting heart rate and HRV are noisy day to day. What they mean together is covered in your morning numbers explained.

The common thread

Illness, travel and short sleep all point the same way. Ease off while the stress is there, return gradually, and don't try to repay missed sessions. Fitness built over months doesn't vanish in a week. It's far easier to lose with an injury from rushing back.

How Stwong handles it

In Stwong, when you're sick, travelling or busy, your coach moves sessions and proposes a new week: easier sessions, fewer sessions, or rest. Each morning it reads sleep and recovery from Apple Health and treats readiness as a trend, the median of three days, so one bad night alone doesn't change the plan. Every change is a proposal you can apply, tweak or keep.

Maya, the longevity coach, is calm and explains the why behind each suggestion. She never rushes anyone back after illness.

Your sleep was short two nights running, so today is a gentle walk. Rest is part of training too. What would help you wind down tonight?

Stwong is a training companion, not medical advice. If you'd like a plan that bends around illness and travel, see how to get Stwong.