01Chapter 1 · The engine and the erg
Hit the split, whatever it costs?
- Reel
- The Why
- Our rule
Transcript
- Hit the split, whatever it costs?
- The split shows the work.
- Effort shows what it cost.
- Heat, same watts? Heart rate climbs.
- Same split. Harder day.
- Our rule: check the cost.
- Easy feels hard? Slow down.
- Use both. Every session.
- See your capacity.
In short
Hitting the split no matter what it costs isn't the rule. Use the split and your effort together.
The split measures the work. Effort out of 10 tells you what that work cost you today.
Ratings of perceived exertion track heart rate, lactate and oxygen uptake. A 2002 meta-analysis called them a valid measure of intensity, if less precise than people assumed.
Heat is one reason the cost moves. In one lab cycling study, heart rate at the same work rose 11% over half an hour at 35 °C, against 2% at 22 °C.
Our rule: check what the split cost you. If an easy day feels hard, ease the split.
Rating the whole session out of 10 is a tested way to track training too.
Read the full explainer: Heart-rate drift and heat: why the same work costs more →
How to run and pace each test, and how to read the result.
See the four engine testsSources
Paper
Borg GA (1982) Psychophysical bases of perceived exertion. Med Sci Sports Exerc 14(5):377-381. PMID 7154893 (the Borg scales for rating perceived exertion; beat 3)
Paper
Chen MJ, Fan X, Moe ST (2002) Criterion-related validity of the Borg ratings of perceived exertion scale in healthy individuals: a meta-analysis. J Sports Sci 20(11):873-899. doi 10.1080/026404102320761787, PMID 12430990 (RPE correlates with heart rate r=0.62, lactate 0.57, %VO2max 0.64; 'a valid measure of exercise intensity' but 'not as high as previously thought'; beats 3 and 8, caption line 3)
Paper
Foster C, Florhaug JA, Franklin J et al. (2001) A new approach to monitoring exercise training. J Strength Cond Res 15(1):109-115. PMID 11708692 ('the session RPE method is a valid method of quantitating exercise training during a wide variety of types of exercise'; caption last line)
Paper
Lafrenz AJ et al. (2008) Med Sci Sports Exerc 40(6):1065-1071, PMID 18461000 (HR +11% vs +2%, min 15-45, 35 vs 22 °C, cycling, 10 trained men; beat 4)
Paper
Wingo JE, Ganio MS, Cureton KJ (2012) Exerc Sport Sci Rev 40(2):88-94, PMID 22410803 ('the increased heart rate reflects an increased relative metabolic intensity during prolonged exercise in the heat'; beat 5)
Worked out
Concept2 pace-to-watts formula: 2:20.0 = 127.6 W
Ours
Our rule: check what the split cost; if easy feels hard, ease the split. Coaching only, not a claim that RPE is more accurate than the split. Shown as OUR RULE, no product
Nothing here is medical advice. The tests are maximal efforts: if you have a health condition or any doubt about training this hard, check with a doctor first, and stop if you feel unwell.