Training load
How much work your workouts add up to, from minutes in each heart rate zone, with a recent average and a longer one.
Pajdo works out each workout's load from heart rate with Edwards' summated heart rate zones: a minute in zone 1 counts once, a minute in zone 2 twice, and so on up to zone 5. Heart rate below zone 1 adds nothing, and a workout without heart rate adds no load. In two small studies of athletes, this score lined up closely with how hard they rated their sessions and with another heart rate load score, Banister's TRIMP.
The daily loads become two averages that give recent days more weight: an acute one over about 7 days and a chronic one over about 28. Rest days count as zero. The acute average is your recent week, the chronic one what you've been used to.
Your zones come from your own heart rate numbers, so your load is best compared with your own weeks, not with a friend's. Apple's Activity app has its own training load, which also uses the effort you rate for workouts, so the two won't match.
What tends to push it up
- More workouts or longer ones
- More time in higher heart rate zones
What tends to pull it down
- Rest days
- Shorter or easier sessions
Worth a try
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.
Give HIIT days some space
HIIT is short bursts of maximum effort broken up with rest, as the NHS puts it. A joint consensus from European sport science and American sports medicine colleges says training works when overload comes with enough recovery.
Even elite endurance athletes do most of their training easy. Reviews of their training suggest two high-intensity sessions a week can be enough to drive progress.
Try it: schedule your interval sessions with at least one easier day between them. Walks, easy rides or a gentle swim are all fair game on the in-between days.
Keep reading
Sources
- Validity of Session Rating Perceived Exertion Method for Quantifying Internal Training Load during High-Intensity Functional Training (Tibana et al. 2018), Sports
- The convergent validity between two objective methods for quantifying training load in young taekwondo athletes (Haddad et al. 2012), Journal of Strength and Conditioning Research
- Track your training load on Apple Watch, Apple Support
- World Health Organization 2020 guidelines on physical activity and sedentary behaviour (Bull et al.), British Journal of Sports Medicine
- 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
- Couch to 5K running plan, NHS Better Health
- The training intensity distribution among well-trained and elite endurance athletes (Stöggl and Sperlich 2015), Frontiers in Physiology
- Physical activity guidelines for adults aged 19 to 64, NHS
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.