Should I do high-intensity interval training? — Whalespan
Should I do high-intensity interval training?
⚠ High risk
Our read is that high-intensity interval training (HIIT) is well-supported for improving various aspects of health and fitness, but should be approached with moderation and proper technique.
✓WELLSUPPORTED
⚠
High-risk intervention — consult a physician before acting.Drug-drug interactions, dose-dependence, and screening contraindications apply.
Consensus
95%
broad agreement
Evidence quality
77/100
developing
Risk
High
specialist only
Cost / month
$
estimated
Effort
Med
time & habit
Abstract
HIIT is well-supported for improving cardiorespiratory fitness, VO2 max, and promoting skeletal muscle adaptations like mitochondrial biogenesis and fat oxidation, according to Rhonda Patrick.
Andrew Huberman and Bryan Johnson note that HIIT can increase testosterone and enhance stress resilience, while Peter Attia and Rhonda Patrick suggest limiting sessions to no more than two per week to avoid potential downsides.
While beneficial for mental health and glucose regulation, excessive HIIT may harm mitochondria and lead to overtraining, as cautioned by Rhonda Patrick and Peter Attia.
Method
A HIIT protocol can include a 10-minute warm-up, a 5-minute maximal effort, and a 10-minute gradual cool-down with deliberate breathing exercises, as suggested by Peter Attia and Andrew Huberman. Bryan Johnson notes that the 4x4 high-intensity training protocol can be performed on various equipment like an elliptical, bike, or by running or swimming. Rhonda Patrick describes the Norwegian 4x4 HIIT protocol as 4 minutes of hard effort followed by 3 minutes of light recovery, repeated 4 times. Andrew Huberman also mentions six maximal all-out sprints on a stationary bicycle, each followed by a one-minute rest, for acute brain performance improvements.
Evidence detail
01Rhonda Patrick states that incorporating vigorous intensity exercise, especially HIIT, improves VO2 max and cardiorespiratory fitness.
02Rhonda Patrick also notes that HIIT and Zone 2 training promote skeletal muscle adaptations including mitochondrial biogenesis, fat oxidation, and mitophagy.
03Andrew Huberman suggests that for women aged 20-30, HIIT can be incorporated by adding sprint interval training to one resistance session or performing at most two HIIT sessions on separate days.
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04Andrew Huberman claims that short, repeated physical stressors like HIIT promote stress resilience, reduce rumination, depression, and anxiety by tuning up the nervous system.
05Andrew Huberman and Bryan Johnson indicate that high-intensity interval training (HIIT) and sprinting increase testosterone, mimicking the neural activity of moving heavy weights.
06Rhonda Patrick states that high-intensity exercise, including HIIT or long steady-state runs, can positively impact mental health and feelings of well-being.
07Rhonda Patrick suggests that high-intensity interval training (HIIT), when volume-matched, may be as good as or slightly better than moderate-intensity training for improving fat-burning capacity.
08Andrew Huberman and Rhonda Patrick note that HIIT protocols, such as one minute on/one minute off repeated six times, can significantly increase BDNF.
09Rhonda Patrick reports that participants with metabolic syndrome who performed the Norwegian 4x4 HIIT protocol 3 times a week for 4 months each year over an 8-year span experienced no increase in medication use.
10Peter Attia and Rhonda Patrick advise that most individuals should limit HIIT sessions to no more than two per week.
11Andrew Huberman states that six maximal all-out sprints on a stationary bicycle, each followed by a one-minute rest, can lead to significant acute improvements in brain performance.
12Peter Attia and Rhonda Patrick claim that HIIT, such as hour-long spin classes, can significantly blunt the negative effects of sleep interruption on glucose regulation.
Caveats
Peter Attia cautions that very high intensity training and extreme diets are not sustainable long-term, and combining them is worse. Rhonda Patrick warns that excessive high-intensity interval training (HIIT) can harm mitochondria and cause mitochondrial dysfunction. Peter Attia also states that high volumes of high-intensity exercise are not the ideal approach to overall fitness. Andrew Huberman suggests that a 3:1 work-to-rest ratio in HIIT, such as 30 seconds of hard effort followed by 10 seconds of rest, may lead to degraded repetition quality and increased injury risk. Rhonda Patrick notes that antihistamines taken before HIIT exercise may blunt exercise-induced benefits. Andrew Huberman indicates that HIIT can interfere with hypertrophy training if calories and rest are not adequately accounted for. Peter Attia warns that HIIT protocols like Tabata, performed five days a week, may lead to overtraining or burnout. Andrew Huberman advises that individuals with poor cardiovascular health should not immediately engage in HIIT protocols. Rhonda Patrick also states that hypoxic training, such as mouth taping during HIIT, is unlikely to potentiate training responses and may compromise performance. Peter Attia questions the assumption that making intervals shorter increases acceptability, as the original Wingate test protocol (30 seconds all-out) was extremely demanding.
What would change this verdict
Rhonda Patrick indicates that there is insufficient evidence to link specific amounts of interval training to reduced risk of all-cause mortality or cardiovascular disease, suggesting that more robust evidence in this area would change the verdict.