Rest is part of training
Fitness grows while you recover, not only while you train. Rest days and good sleep let a hard session pay off.
Training is the push; recovery is when your body adapts to it. A joint consensus from the European College of Sport Science and the American College of Sports Medicine puts it simply: getting better needs overload and enough recovery. A short dip after a tough block can turn into a gain once you've rested, while hard training with too little recovery can keep performance down for weeks.
How long recovery takes depends on the session. A review of heart rhythm after aerobic exercise found the heart's resting control (what HRV reflects) took up to 24 hours to settle after easy sessions, 24–48 hours after hard but steady threshold work, and 48 hours or more after high-intensity sessions. Fitter people bounced back faster.
Sleep is one of the best-studied recovery tools, next to easier days and time off. A 2018 recovery consensus also stresses that people respond differently to the same training, so your own data is a useful guide.
That's why Pajdo notices when training ramps up fast while sleep or HRV lags behind, and treats it as a nudge to ease off, not a warning.
Worth a try
Mix running with walking
The NHS Couch to 5K plan opens with 1 minute of running and 90 seconds of walking, repeated, after a 5 minute warm-up walk. Each week the runs get a little longer, and by week 9 you're running for 30 minutes.
The plan has three runs a week with a rest day between each, and says to go at a pace that feels comfortable.
Try it: set an interval timer for run 1, walk 1:30, and repeat it 7 times. Stay at that level until it feels easy, then stretch the runs a little.
Add a little at a time
WHO's activity guidelines say to start small and gradually increase how often, how hard and how long you go. Training works when extra load comes with enough recovery, according to a joint statement from European sport science and American sports medicine colleges.
In practice that means changing one thing at a time. Add a few minutes to one run, or add one more run a week, then hold there until it feels routine.
Rest days count as training too. The NHS beginner plan puts one between every run.
Keep most rides easy
Studies of professional and elite cyclists show they spend most of their riding time at low intensity, with a smaller share of hard efforts. A joint sports medicine consensus adds that training works through overload paired with enough recovery.
That pattern comes from well-trained riders, so treat it as a sensible shape, not a strict recipe.
Try it: after a hard or long ride, make the next one an easy spin in a light gear where you could chat the whole way. Keep your harder rides to one or two a week.
Keep reading
Sources
- Prevention, diagnosis, and treatment of the overtraining syndrome: joint consensus statement of the ECSS and ACSM (Meeusen et al. 2013), Medicine & Science in Sports & Exercise
- Recovery and performance in sport: consensus statement, International Journal of Sports Physiology and Performance (Kellmann et al. 2018)
- Cardiac parasympathetic reactivation following exercise: implications for training prescription, Sports Medicine (Stanley et al. 2013)
- Couch to 5K running plan, NHS Better Health
- Get running with Couch to 5K, NHS Better Health
- World Health Organization 2020 guidelines on physical activity and sedentary behaviour (Bull et al.), British Journal of Sports Medicine
- The training intensity distribution among well-trained and elite endurance athletes (Stöggl and Sperlich 2015), Frontiers in Physiology
Checked against these sources on September 15, 2026.
This is general wellness information, not medical advice. If a number worries you, or stays away from your usual for a while, talk to a doctor.