Metabolic demands of a simulated smoke-diving drill

Figures & data

Table 1. Characteristics of all professional and contract firefighters. An activity rating of 7 corresponds to over 3 hours of strenuous exercise per week.

	All firefighters (n = 37)		Professional (n = 32)		Contract (n = 5)
	Mean (SD)	Range	Mean (SD)	Range	Mean (SD)	Range
Age (years)	36.1 (9.0)	21–56	37.4 (8.5)	24–56	27.8 (8.5)	21–42
Height (cm)	177.7 (6.9)	167–196	177.5 (6.1)	167–196	179.4 (7.0)	169–188
Weight (kg)	82.1 (8.5)	68–107	82.8 (8.6)	68–107	77.4 (7.2)	70–89
Activity rating (0–10)	6.9 (0.8)	5.0–8.5	7.0 (0.8)	5.0–8.5	6.6 (0.5)	6.0–7.0
V̇O2max^a (ml/kg/min)	48.6 (7.3)	37.1–67.0	48.6 (7.4)	37.1–67.0	48.6 (6.9)	39.0–56.7
V̇O2max^a (l/min)	3.94 (0.59)	2.92–5.43	3.96 (0.59)	2.92–5.43	3.78 (0.65)	3.00–4.65
HRmax^b (bpm)	190 (7)	174–206	190 (7)	174–206	193 (4)	188–200

^a V̇O_2max: maximal oxygen consumption.

^b HR_max: maximal heart rate.

Figure 1. (a) Going under obstacles, (b) hose pull.

Figure 2. Heart rate and oxygen consumption of one participant averaged in 30-second time intervals during baseline, Finnish smoke-diving drill and 10-minute recovery.

^aTask 1: walking without and with two rolls of hose; Task 2: stair climbing; Task 3: hammering a truck tire; Task 4: hose pull and going over and under obstacles; Task 5: hose rolling.

Table 2. Physiological parameters measured during Finnish smoke-diving drill, mean (SD).

	Walking without and with two rolls of hose (Task 1)	Stair climbing (Task 2)	Hammering a truck tire (Task 3)	Hose pull and going over and under obstacles (Task 4)	Hose rolling (Task 5)	Whole drill
Duration (s)	158.9 (17.1)	152.4 (15.2)	49.2 (26.4)	159.6 (43.3)	70.4 (13.2)	836.1 (40.4)
HR^a (bpm)	117.7 (12.6)	137.5 (12.7)	153.9 (14.8)	164.8 (10.8)	157.7 (13.3)	147.1 (12.4)
HR^a (%max)	62.0 (6.3)	72.4 (6.3)	81.0 (7.1)	86.8 (4.9)	83.1 (7.0)	77.5 (6.1)
V̇O2^b (l/min)	1.69 (0.20)	2.36 (0.28)	2.06 (0.35)	2.87 (0.40)	2.17 (0.35)	2.34 (0.28)
V̇O2^b (ml/kg/min)	20.8 (2.8)	28.9 (3.2)	25.1 (3.7)	35.2 (4.6)	26.6 (3.7)	28.6 (3.0)
V̇O2^b (%max)	43.3 (6.9)	60.1 (8.0)	52.3 (9.9)	73.1 (10.9)	55.3 (9.4)	59.2 (7.8)
VE^c (l/min)	38.5 (6.1)	53.8 (8.5)	66.1 (11.7)	88.0 (15.1)	76.6 (12.6)	67.0 (10.4)
RER^d	0.78 (0.05)	0.85 (0.05)	0.99 (0.07)	1.02 (0.05)	1.10 (0.04)	0.94 (0.04)
[La-]^e (mmol/l)						7.3 (2.3)
RPE^f	9.1 (1.5)	11.4 (1.7)	13.0 (2.0)	15.1 (1.9)	12.2 (2.0)

^a HR: heart rate.

^b V̇O₂: oxygen consumption.

^c VE: ventilation.

^d RER: respiratory exchange ratio.

^e [La-]: blood lactate concentration.

^f RPE: perceived exertion.

Table 3. Physiological parameters measured at baseline and 10- and 30-minute recovery after Finnish smoke-diving drill, mean (SD).

	Baseline	10-min recovery	30-min recovery
HR^a (bpm)	75.3 (7.1)	98.6 (9.3)***	86.8 (8.5)***$$$
V̇O2^b (l/min)	0.46 (0.06)	0.54 (0.07)***
V̇O2^b (ml/kg/min)	5.7 (0.9)	6.6 (0.9)***
VE^c (l/min)	13.8 (2.2)	18.3 (3.1)***
[La-]^d (mmol/l)	1.5 (0.4)	5.1 (1.8)***	3.2 (0.9)***$$$

* Statistically significant difference from baseline value, p < 0.001.

^$ Statistically significant difference from 10-min recovery value, p < 0.001.

^a HR: heart rate.

^b V̇O₂: oxygen consumption.

^c VE: ventilation.

^d [La-]: blood lactate concentration.

Table 4. Pearson correlation coefficients controlled for age between maximal oxygen consumption and physical strain during Finnish smoke-diving drill.

	1.	2.	3.	4.	5.	6.	7.	8.
1. V̇O2max^a (ml/kg/min)	1.00	0.80***	0.53***	0.29	–0.72***	–0.48**	–0.50**	–0.37*
2. V̇O2max^a (l/min)		1.00	0.21	0.56***	–0.73***	–0.57***	–0.54***	–0.20
3. V̇O2^b (ml/kg/min)			1.00	0.52**	0.19	0.08	0.03	0.09
4. V̇O2^b (l/min)				1.00	0.10	–0.11	–0.04	0.25
5. %V̇O2max^c					1.00	0.59***	0.56***	0.55***
6. HR^d (bpm)						1.00	0.90***	0.41*
7. %HRmax^e							1.00	0.40*
8. [La-]^f (mmol/l)								1.00

*p < 0.05.

**p < 0.01.

***p < 0.001.

^a V̇O_2max: maximal oxygen consumption.

^b V̇O₂: oxygen consumption.

^c %V̇O_2max: oxygen consumption in relation to maximal.

^d HR: heart rate.

^e %HR_max: heart rate in relation to maximal.

^f [La-]: blood lactate concentration.

Data availability statement

The datasets generated and/or analysed during the current study are available from the corresponding author on reasonable request.