REF-1468 · Hawari et al., 2013 · Inhalation Toxicology · Paper · PubMed

What does a hookah do to exercise half an hour later?

In 24 young male users, VO2 fell 1.86 to 1.7 L/min and oxygen pulse dropped in a fixed test; effort felt harder. Pilot, no control group. From the abstract.

Main caveat: Abstract only; no SDs or P values for individual results.
limited, mixed evidenceMeasured on non-athletes and recreational people

Hawari and colleagues (King Hussein Cancer Center, Amman) characterised the acute effects of waterpipe smoking on lung function and exercise capacity. Twenty-four healthy male waterpipe users, mean age 20.4 years, were tested after abstaining for at least 48 h and again within 0.5 h of a 45-min session, with spirometry, diffusing capacity and a time-limited cycle test.

After the session exhaled CO rose from 3.7 to 24.4 ppm, oxygen consumption fell from 1.86 to 1.7 L/min, baseline respiratory rate rose from 17.7 to 19.7 breaths/min, forced expiratory flow over the middle half of FVC fell from 5.51 to 5.29, and perceived exertion rose at mid and peak exercise.

Resting systolic pressure and pulse pressure rose (118.9 to 129.2 and 45.3 to 55.6 mmHg). During exercise oxygen pulse fell (10.89 to 9.97 mL/beat), and the heart-rate to oxygen-consumption relationship rose (3.52 to 3.91 beats/mL/kg). The authors say acute waterpipe smoking appears to impair lung function and exercise capacity, and call for larger studies.

Our reading: the only exercise test straight after a hookah in the base, and the direction fits CO: less oxygen per heartbeat and a harder feel. But a fixed order, one group and a test that stops at 10 min leave the size uncertain.

Protocol

Participants: n = 24 healthy male waterpipe smokers, mean age 20.4 years.
Design: single group; test after at least 48 h without waterpipe, retest within 0.5 h of a 45-min session; always in that order.
Exercise test: time-limited cycle ergometer test: 2-min 20-W warm-up and 25-W increase every 2 min for 10 min.
Other tests: spirometry, diffusing lung capacity, Borg scale.
Funding and interests: PubMed lists non-US government support; the record names no funder and holds no conflict statement.

Key Results

OutcomeBeforeAfter
CO level (ppm; printed without "exhaled", which the unit implies)3.724.4significant
Oxygen consumption (L/min)1.861.7significant
Oxygen pulse in exercise (mL/beat)10.899.97significant
Heart rate-oxygen consumption relationship (beats/mL/kg)3.523.91significant
Resting respiratory rate (breaths/min)17.719.7significant
Forced expiratory flow, mid FVC (printed as L)5.515.29significant
Resting systolic pressure (mmHg)118.9129.2significant
Resting pulse pressure (mmHg)45.355.6significant
Perceived exertion: higher at mid and peak exercise (no values in the abstract).
Not in the abstract: SDs, P values for each, the point in the test where oxygen consumption was measured, COHb.

Mechanisms

Measured: higher exhaled CO, lower oxygen pulse, more heart rate for the same oxygen use, higher perceived effort.
Authors' interpretation: acute waterpipe smoking appears to impair lung function and exercise capacity.
Inference: oxygen bound up by CO would lower oxygen pulse and push heart rate up at the same work (PHYS-09, PHYS-12). Lower oxygen consumption at set workloads is harder to read, since the abstract does not say at which point it was measured or whether it means less delivered oxygen, a shorter test or a change in efficiency.

Practical Application

What does a hookah do to exercise half an hour later? In 24 young male users, VO2 fell 1.86 to 1.7 L/min and oxygen pulse dropped in a fixed test; effort felt harder. Pilot, no control group. From the abstract.
Reading the session: after a hookah, higher heart rate and harder effort at the same work may be the CO, not lost fitness (PHYS-12); this is an inference from the direction here.
Timing: this measured half an hour after, not the morning after; for 10 h see REF-1460. Not from this paper; the base's own practice: any "easy next morning" rule is practice and does not carry this entry's level.
What it does not show: performance in a race or to exhaustion; effects at longer delays; anything in women or trained athletes.

Limitations

Abstract only; no SDs or P values for individual results.
Fixed order, no control: all first tests were before all second tests; expectation is not controlled, as nobody can be blinded to a hookah.
Abstinence differs from usual state: the baseline was at least 48 h off, not typical of a regular user's day.
Who was measured: young male users of unknown fitness.
Time-limited test: no peak capacity or performance.
Unit oddities as printed: forced expiratory flow in L and "pulse pressure product" in mmHg/min.
Funding and interests: non-US government support per PubMed; no statement in the record.
How this entry was checked and changed
Why this level

(from the abstract) — an uncontrolled pre-post pilot (rubric B) with a further serious limitation: fixed order, abstract only, and a time-limited test that gives no time to exhaustion or race measure