IB Summer Analyst 2026

·

What the data says

· fundamental read
ASSOCIATIONS ONLY

Sleep was recorded on 68 of 68 eligible internship mornings (100% coverage). Median sleep was 6.1 hours; 36 nights were over six hours and 9 were under four hours.

Compared with all available pre-internship records, available data suggest sleep duration was 0.7 hours lower (consistent evidence), recovery was 12 points lower (consistent evidence), HRV was 12 ms lower (consistent evidence), and resting heart rate was 7 bpm higher (consistent evidence).

Following mornings after the listed social nights were associated with 1.3 more hours of sleep and 15 points lower recovery in weekday-matched comparisons (matched n≥18; evidence varies by metric).

Recorded sleep
68 of 68
WHOOP
Over six hours
36 nights · 53%
Under four hours
9 nights · 13%
Median sleep
6.1h
Median bedtime
3:17 AM
Median wake time
8:41 AM

Each cutoff is a descriptive threshold, not a medical diagnosis or personalized target.

This observational analysis describes associations, not causal estimates; work-hour intensity, alcohol exposure, travel, illness, and other factors were not available as controls.

The all-history pre-internship benchmark is neither duration- nor season-matched to the internship window.

Daily recovery and sleep

· health through Aug 7 · NYC events through Aug 9

Social events are plotted on the following morning. Filled event bubbles sit on recorded recovery; hollow bubbles above the plot indicate no recovery value.

Recovery

Recovery (%)Following-morning event · 20No recovery recorded

Sleep duration

Over 6h · 36Under 4h · 9

Sleep performance

Sleep performance (%)

Cardiovascular

HRV (ms)RHR (bpm)

Hover a point to inspect its day and values. Keyboard: focus a chart and use the left and right arrow keys.

Comparisons at a glance

· first cohort minus second
Internship health comparisons showing cohort means, medians, coverage, changes, and evidence.
MetricCohorts · first vs secondChangeEvidence
Internship − all prior dataInternship first · All prior data second
Sleep duration
Mean5.9h vs 6.7hMedianmedian 6.1h vs 6.6hCoverage68 of 68 (100%) vs 268 of 275 (97%)
−0.7 hMedian Δ −0.5 h
Consistent association
Sleep performance
Mean55% vs 65%Medianmedian 60% vs 72%Coverage68 of 68 (100%) vs 268 of 275 (97%)
−9 ppMedian Δ −13 pp
Consistent association
Recovery
Mean42% vs 54%Medianmedian 40% vs 59%Coverage68 of 68 (100%) vs 268 of 275 (97%)
−12 ppMedian Δ −19 pp
Consistent association
HRV
Mean29ms vs 41msMedianmedian 29ms vs 42msCoverage68 of 68 (100%) vs 268 of 275 (97%)
−12 msMedian Δ −12 ms
Consistent association
Resting heart rate
Mean73bpm vs 66bpmMedianmedian 71bpm vs 64bpmCoverage68 of 68 (100%) vs 268 of 275 (97%)
+7 bpmMedian Δ +7 bpm
Consistent association
Social − non-socialSocial-night mornings first · Non-social-night internship mornings second
Sleep duration
Mean6.9h vs 5.6hMedianmedian 6.7h vs 5.7hCoverage18 of 18 (100%) vs 50 of 50 (100%)
+1.3 hMedian Δ +1.1 hMatched weekday +1.3 h · n=18
Consistent association
Sleep performance
Mean53% vs 56%Medianmedian 53% vs 61%Coverage18 of 18 (100%) vs 50 of 50 (100%)
−3 ppMedian Δ −8 ppMatched weekday −3 pp · n=18
Consistent association
Recovery
Mean36% vs 44%Medianmedian 31% vs 41%Coverage18 of 18 (100%) vs 50 of 50 (100%)
−8 ppMedian Δ −11 ppMatched weekday −15 pp · n=18
Consistent association
HRV
Mean23ms vs 32msMedianmedian 20ms vs 32msCoverage18 of 18 (100%) vs 50 of 50 (100%)
−9 msMedian Δ −13 msMatched weekday −14 ms · n=18
Consistent association
Resting heart rate
Mean77bpm vs 71bpmMedianmedian 78bpm vs 69bpmCoverage18 of 18 (100%) vs 50 of 50 (100%)
+6 bpmMedian Δ +9 bpmMatched weekday +8 bpm · n=18
Consistent association
Weekend − worknightWeekend mornings first · Worknight mornings second
Sleep duration
Mean7.2h vs 5.4hMedianmedian 7.5h vs 5.6hCoverage18 of 18 (100%) vs 49 of 49 (100%)
+1.7 hMedian Δ +1.9 h
Consistent association
Sleep performance
Mean60% vs 54%Medianmedian 61% vs 57%Coverage18 of 18 (100%) vs 49 of 49 (100%)
+7 ppMedian Δ +4 pp
Consistent association
Recovery
Mean45% vs 40%Medianmedian 40% vs 38%Coverage18 of 18 (100%) vs 49 of 49 (100%)
+4 ppMedian Δ +2 pp
Consistent association
HRV
Mean27ms vs 30msMedianmedian 27ms vs 32msCoverage18 of 18 (100%) vs 49 of 49 (100%)
−2 msMedian Δ −5 ms
Consistent association
Resting heart rate
Mean77bpm vs 71bpmMedianmedian 78bpm vs 69bpmCoverage18 of 18 (100%) vs 49 of 49 (100%)
+5 bpmMedian Δ +9 bpm
Consistent association
Late − early internshipLate internship first · Early internship second
Sleep duration
Mean6.1h vs 5.7hMedianmedian 6.1h vs 5.7hCoverage34 of 34 (100%) vs 34 of 34 (100%)
+0.4 hMedian Δ +0.5 h
Consistent association
Sleep performance
Mean57% vs 54%Medianmedian 61% vs 60%Coverage34 of 34 (100%) vs 34 of 34 (100%)
+3 ppMedian Δ +1 pp
Consistent association
Recovery
Mean43% vs 41%Medianmedian 40% vs 38%Coverage34 of 34 (100%) vs 34 of 34 (100%)
+3 ppMedian Δ +2 pp
Consistent association
HRV
Mean28ms vs 31msMedianmedian 27ms vs 32msCoverage34 of 34 (100%) vs 34 of 34 (100%)
−3 msMedian Δ −5 ms
Consistent association
Resting heart rate
Mean74bpm vs 71bpmMedianmedian 73bpm vs 70bpmCoverage34 of 34 (100%) vs 34 of 34 (100%)
+3 bpmMedian Δ +3 bpm
Consistent association

Internship comparisons use each metric’s full available pre-internship history from the same selected source. Positive changes mean the first cohort was higher. Social-night rows also show the weekday-matched estimate when available.