Effect of Weight and an Increased Workload on Heart Rate and Blood Pressure

Abstract

Previous studies have shown that personal protective equipment (PPE) is responsible for increases in heart rate (HR) and VO2max response in firefighters (FF), but has not been examined in collegiate lacrosse players. We have found that FF have exaggerated blood pressure (BP) responses to a treadmill test, and during recovery when wearing PPE (data unpublished). PURPOSE: To compare the effects of weight and an increased workload on BP and HR, between FF and lacrosse players. METHODS: Division III lacrosse players (5M, 20.4 ±0.5yrs) and volunteer firefighters (5M, 21.8 ±2.2yrs) who were matched by body size (FF BMI 26.9 ±3.7kg/m2; lacrosse BMI 26.3 ±3.5 kg/m2, p=0.79) came to the lab for two visits within two weeks for two symptom-limited maximal treadmill tests. The first treadmill test (Regular) was completed following Bruce Protocol in normal clothing; ECG, BP, and HR were continuously monitored. The second treadmill test (PPE) was completed following Bruce Protocol while participant was wearing full gear or PPE; BP and HR were monitored. Changes in HR and BP were compared within groups. RESULTS: Between FF and lacrosse players, gear weight (FF 54.2±4.5 lbs.; lacrosse 6.1±2.1 lbs.), reported number of times exercise/week (FF 1.8±1.5; lacrosse 5.2±0.4), Regular HRmax (FF 230.2 ±31.0 bpm; lacrosse 190.4 ±9.2 bpm), and Regular VO2max (FF 40.2±8.0 ml/kg/min; lacrosse 50.4±4.7 ml/kg/min) were different between groups (p<0.05 for all). For lacrosse players, there were no differences in the BP at each stage or HR at each minute - in Regular compared to PPE. However, for the FF there was a difference in the stage systolic BP and minute HR - in Regular compared to PPE (p<0.05 for all). CONCLUSION: Division III lacrosse players are not affected by the weight of their gear in the same way as FF. Future research should be done to verify the effect of different weights of gear and an increased workload on HR and BP responses.