Time trials
A time trial is a solo 5K run as hard as you can hold it. Every couple of months it refreshes your fitness estimate, so your training paces keep up with you.
A time trial is a race without the race: you, 5 km and an honest, even effort after a warm-up. The time says more about your fitness right now than any easy run can, so it's the cleanest way to refresh your paces.
Spacing matters. When recreational runners (all men) ran the same 5K twice on a track a few days apart, their times varied by about 3.4%. In training studies, 8 to 10 weeks improved recreational runners' 10K and 2 km times by about 3 to 5%. Test every few weeks and you mostly measure a good or a bad day.
In Pajdo's plan the time trial takes the first harder day of the week after every other lighter week: usually weeks 5, 13, 21 and so on, on fresh legs. There's no pace alert, just you and the distance. Afterwards, add your time in the race goal's form and your paces update. One slow day can't drag them down: while your earlier result is under 90 days old, the faster one counts.
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Sources
- Reprodutibilidade do desempenho em provas de corrida de 5 e 10 km em pista de atletismo, Revista Brasileira de Ciências do Esporte (Andrade Machado et al. 2015)
- Does polarized training improve performance in recreational runners?, International Journal of Sports Physiology and Performance (Muñoz et al. 2014)
- Effects of different training intensity distribution in recreational runners, Frontiers in Sports and Active Living (Festa et al. 2020)
Checked against these sources on October 16, 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.